Part 5 for stage 4

Fortunately, as with so many things in life, everyone has their preferences...
More RPM and more peak power or more torque at low RPM.

That's why in today's part I'm looking for more... But not top performance, but for speed range and torque. The "tractor engine" is sought.

In part 4 with stage 3, I looked in the direction of the higher control angle by raising the cylinder and making a small adjustment to the exhaust. If I were now to increase the exhaust further in order to perhaps achieve higher peak performance and speed, the way would be backwards; to try the cylinder with more blowdown at lower control angles installed.

So today I lower the cylinder. Overall, this results in lower control angles, but the pre-release increases slightly. The smaller transfer angle should allow the cylinder to produce a little more torque at low rpm.

The spacer on the cylinder head was changed from 1mm to 3mm compared to the third construction stage. At the cylinder base, the 2mm spacer leaves the field and the cylinder is only supported by a normal 0.3mm thick gasket. The squeezing edge remains at 1.3mm, as with the other construction stages.

In the following graphs are the current curves of construction stage 4 RED to see. The curves from the previous stage three appear in BLUE.

Elron is the first to show what he thinks of the change.

As can be expected, the absolute top performance drops slightly, but the maximum performance and torque shift in the direction of lower speeds. The torque increases slightly and feeds the range between 5100 and 7000 rpm.

The Polini box, which is more intended for engines with less transfer time, is placed next on the exhaust port.

At first glance, the curves may seem sobering. On closer inspection, the Polini Box turns out to be a real torque animal. At the end of this series of tests, it will rank second in terms of torque with 37.4Nm. The graph already passes the 4700 hp mark at 20 rpm. The maximum power shifts by an impressive 1000 rpm in the direction of a lower speed, culminating at 6400 rpm. The maximum torque pulls at the rear wheel at 6000 rpm. An engine constructed in this way is just begging for a long gearbox.

This allows the M244 to move over the asphalt with extreme shift laziness. Jack off the stand, shift into gear 4 and just pull the cable. Don't worry, it will be quick...


The aged all-rounder in the field.

The JL left arm puts its torque in the range between 5000 and 7000 rpm and thus offers more drivability. Although the peak power falls by one hp, the JL can still offer very good drivability in the field of resonance exhaust systems.

New Line

The handwork from the north is also responding to the adjustments as expected. Already at 5000rpm, 20 horses are ready to move significantly. Full torque is available at 6100 rpm. Although it pushes the absolute top performance down a bit and the Newline gives up 2 horses in favor of the early torque, it is happy to take the larger pre-release in order to go over 10.000 rpm and maintain it there with over 20 hp.
The Newline behaves here almost like a box exhaust system, seasoned with a significant torque kick.

Posch Nessi

The sea monster ducks its head slightly due to the reduced steering angles. But that's not bad at all. As with the Newline, the rev range shifts slightly towards early revs and develops more torque in the process. At 5200 rpm the curve already exceeds the 20 hp mark. The slightly increased pre-let helps the Nessi to a wider speed range.

Posch Racing Resi

The lush Resi handles the steering angle that is unsuitable for you amazingly well. Although it also loses peak performance, it gives an idea of ​​the bandwidth that can be possible with the appropriate control angles and more forward airflow. With a speed range of almost 4100 rpm, it is in the top league here.


The Lakers, made for a lot more alert, don't like the slack head angles that much. The exhaust craves for larger time cross sections. The speed range shifts to lower speeds as expected, but the low time cross sections are not the right playing field for the Lakers. But his chance will come with the following expansion stages...


Here again all maximum values ​​in the overview

In the fourth part of our little blog series let's make the following changes to our test engine:

The cylinder is at the foot with two 1mm Spacers Raised by a further 2mm compared to construction stage 0.5. This changes the control angle of the transfer channels from 124 ° to 126 °. Milling is used to adjust the outlet to a control angle of 190 °. For this purpose, the outlet in the cylinder was raised by 1.8mm. The outlet width remains unchanged at 57%.


The first attempts are made with the Elron


A little more nervous exhaust systems would show a clear shift in the direction of performance with the changes made, but the Elron is almost unimpressed by the specifications of the cylinder and retains control over the characteristics of the engine. A slight increase in the maximum values ​​after the decimal point only indicates that the Elron has noticed that the cylinder is sending a clearer signal through the exhaust. However, the maximum torque remains at the same level as in the first construction stage.
The available speed range is reduced by 500 rpm to 3540 rpm.


Polini box


As a box exhaust, the Polini exhaust system reacts as expected. Similar to the Elron, the can from Italy only shows small reactions. The lower effective compression makes the curve dip somewhat in the increase between 4000rpm and 6200rpm. The system implements the slightly increased time cross-section at the outlet window with a gain of just over one horsepower at its peak.
The maximum torque remains the same at 35.2Nm and only shifts by a few hundred revolutions in the direction of higher speeds.
With a bandwidth of 3800 revolutions, the Polini system is slightly behind position 2, but this experiment shows that the box does not necessarily prefer the very small control angles. In direct comparison to construction stage 1, the bandwidth and maximum values ​​have increased significantly.




JL left hand / JL performance


Our test subject had a short break in the previous construction phase, due to appointments away from home; but now plays again in the third construction stage. Therefore, here is the comparison between levels 1 and 2.
So that it is also very clear how clearly an exhaust can behave when it is operated from other control angles. JL, who is considered good-natured, turns out to be a very approachable partner in search of performance.
At the top, the JL provides almost five and a half more horses and climbs over the 36PS line in the graph. The torque remains at 32.6Nm at the same level as in the first attempt. However, the torque extends over a much wider range - beyond 7000rpm. The performance peak is reached with 36.4PS at 8400rpm. The JL falls below the 25 HP line considered in the bandwidth only beyond 9600 rpm and can therefore not be described as a lazy speed. In general, the graph shifts significantly in the direction of higher speeds. With a bandwidth of only 3400 revolutions, the JL even lags behind the Elron and brings up the rear in terms of bandwidth in this construction stage.


Scooter and Service Newline


The angular power man from the north feels right at home in this expansion stage and takes two top marks with him.
There are no notable changes in the rise in the newline, but it does quite a bit due to the larger advance angle in the engine speed range. With 37.3Nm, it takes the top position in terms of torque in the third construction stage. The available speed range is narrower compared to the previous tests, but here too the Newline achieves a range of 4000 revolutions. With these values, considerations germinate after a longer primary with 24-60 ...




Similar to the Elron, the Seemonster from Posch Performance is not quite sure what to do with the changed steering angle. The maximum torque remains the same and the peak power increases by one horsepower. While the Nessie was way ahead in level 1 with 4300 revs in the range, the available rev range in level three goes a bit to the diving station and is in the upper midfield with 3700 revs.




Racing Resi


Racing Resi tastes the changes better. Rather attached to the higher steering angles, the Resi develops one more horsepower at the top and adds torque, which hardly affects the bandwidth on the 25HP line. In absolute terms, the Resi holds the position of the highest peak performance at this level with 38.9PS. We are slowly approaching the 40 HP brand with the expansion stages.






With 126 ° to 190 ° the Lakers is not yet in its comfort zone. Although it also clearly converts the changed control angle into performance. With 38.4PS at the top, it is only just behind the Resi. With a speed range of 3700 revolutions, which now extends to 10.100rpm, the Lakers shows where the journey can go with suitable peripherals.

Here in the overview the results. Best values ​​are highlighted in green.

M244 Quattrini cylinder Vesoa on the test bench

Quattrini M244 king shaft - the super tourer in the second expansion stage "outlet" M244_2

M244 - part 3

Im second part this Series we simply adapted the cylinder and the engine housing to each other and put the cylinder on the engine without further processing "Plug & Play".

This resulted in very moderate control angles:

  • with 124 ° transfer angle
  • and 177 ° outlet angle

Some exhaust systems get along well with these short steering angles and thus provide quite astonishing performance.

On the other hand, the exhaust systems, which are trimmed more for performance, require larger steering angles.
In the course of the test series, the character of the performance curve of one or the other exhaust system will change.
Therefore we remove some material from the M244 in the exhaust duct and set the upper edge of the exhaust to 182 °. The outlet width remains unaffected and remains at a chord dimension of around 57%.

As a spacer, we use 1.5 mm on the cylinder head and the cylinder base plus a 0.3 mm seal on the cylinder base. This means that the control angles remain at 124 °:

  • 124 ° transfer angle
  • 182 ° outlet angle
  • 57% tendon size

Cylinder cooling hood for the long M244 Quattrini

In the meantime we have also received a matching cylinder cooling hood from GRP specialist BSK. You can find the blog here -> QUATTRINI GRP CYLINDER HOOD



The Elron uses the larger steering angle rather cautiously. With a 1,7 HP increase in peak performance, a slight loss in torque and a little less band due to the 300 rpm later entry, the exhaust shows that it takes note of this requirement but does not yet represent the right playing field for the concept . However, the Elron takes this very calmly. Presumably, the exhaust will deliver a very pleasing performance curve even with significantly different control angles and thus the concept does not completely submit to the dictates of the control angle.

Test bench diagram as PDF:  M244_1_2_ELRON


The Polini Box reacts very clearly to the small change in the outlet and provides a lot of power. The box adds over 3PS and not quite 1 Nm. The speed range is even wider by 700 rpm, whereby the graph does not even pass the 100 hp mark at 25 rpm until 5.500 rpm later and the output lasts significantly longer up to 9.400 rpm. The control angles of 124 ° to 182 ° seem to be clearly pleasant to the Polini Box.


Test bench diagram as PDF:  VGL_M244_1_2_POLINI

Test Scooter and Service NEWLINE

The Newline generally shows a different character in terms of power increase at small steering angles than the Elron or the Polini Box.

Similar to the Elron is the rather unimpressed behavior on the changed exhaust control angle. The peak power increases by almost one hp, the maximum torque remains almost identical and the speed range becomes somewhat narrower, as with the Elron, due to the later start of resonance. Even in the second expansion stage, the Newline retains the top position when it comes to torque with 36,7 Nm at 6.137 rpm.


Test bench diagram as PDF:  M244_1_2_NEWLINE

Test Posch Nessie

The Nessie, like the Newline, is intended for moderate control angles, and also shows the clear shift at the start of resonance. Viewed in absolute terms, the Nessie “only” adds 2,5 HP to the top, but in the range between 6.300 rpm and 9.000 rpm it can be clearly seen that the larger outlet angle significantly increases the performance over this range.

Test bench diagram as PDF: M244_1_2_NESSIE

Test Posch Racing Resi

The Racing Resi with its imposing, bulbous appearance already gives the impression of performance and the greed for steering angles. Therefore, the slightly increased outlet angle is not enough to achieve absolute top performance. Here, too, the start of the response is much later. At its peak, the Resi increases by 1,7 HP and this can use the slightly increased exhaust control angle between 7.300 rpm and 10.000 rpm to increase power and torque.


Test bench diagram as PDF: M244_1_2_RAC_RESI

Kingwelle Lakers test

The robust racing exhaust from Lake Constance has already shown on the plugged-in version of the M244 that it is also a good all-rounder. As with all other tested resonance systems, the speed range also shifts in the direction of higher speed, but without the bandwidth being affected. With a band of almost 4.300 rpm, it provides the largest bandwidth in this expansion stage. With 37,8 PS at its peak, the Lakers, at least in this expansion stage, has to admit defeat to the Resi with 37,9 PS - but we are only just warming up on the subject of the steering angle.


Test bench diagram as PDF: M244_1_2 LAKERS

The results of the test bench runs, expansion stage 1_2

Here again the results in tabular form. The best values ​​are highlighted in green for each construction stage

Part 4 is already in progress ...


Quattrini M244 Kingwelle - the super tourer

Quattrini M244 king shaft - the super tourer in the first expansion stage "Plug & Play" M244_1

That's part 2 of this Quattrini M244 - Series. In this first construction stage, M244_1, we have the M244 without any further changes, only with spacers on the cylinder head and the cylinder base our engine eingerichtet.

We have entered the resulting control angles in the list for the test plan.

In terms of design, this setup is in the middle of the range of expansion stages.


We have the control angle in the list for the test plan


First we send the all-purpose weapon from Polini into the race.

Polini Box exhaust Vespa

Performance diagram Polini exhaust on Quattrin M244i

Test bench diagram POLINI BOX exhaust on Quattrini as PDF: M244_1_POLINI

The result is quite clear. Already at 4000rpm there are 15 HP and 26Nm on the rear wheel.

The maximum values ​​are 30.5PS at 6500rpm and 34.4Nm at 5900rpm.
Even at 9500rpm there are still 22PS on the rear wheel. This constellation already calls for a longer primary translation.



The next test subject comes from FalkR and listen to the name Elron's.

Performance diagram FALRR ELRONi exhaust on Quattrin M244i

Test bench diagram FALKR ELRON exhaust on Quattrini as PDF: M244_1_ELRON

With regard to the maximum values, the Elron ranks as real resonance exhaust already above the Polini Box. But the tide is turning only beyond the 6500rpm in favor of the Elron. In the range before 6500 rpm, the Polini Box has the lead here. After passing the 6500rpm mark, the Elron gains significantly and is above the Polini Box up to the end of revs beyond the 10500rpm.



Another old friend is that JL performance.

JL performance

Performance diagram JL PERFORMANCE exhaust on Quattrin M244i

Test bench diagram JL-PERFORMANCE exhaust on Quattrini as PDF: M244_1_JL_LH

The somewhat outdated concept of the JL still delivers reliable values ​​today. The JL does not cope with the first stage of the engine quite as well as the Elron. With 31PS at 8200rpm, that's something like suffering at a high level. The rather gentle entry and a good performance of 16PS at 4000rpm make the JL a very drivable exhaust with a good start in Reso optics.




The Newline exhaust from Scooter & Service is with us in Scooter Center Shop .


Performance diagram SCOOTER & SERVICE NEWLINE exhaust on Quattrin M244i

Test bench diagram NEWLINE exhaust on Quattrini as PDF: M244_1_NEW_LINE

The new line Scooter and Service from Hamburg already delivers its maximum power of 6300PS at 32rpm. Even if the playing field doesn't quite fit the Newline, which would like to see a little more steering angle, the manual work from Hamburg delivers a remarkable 6000Nm already at 36rpm. The torque beast in this expansion stage



As the first representative of the “Performance” department, we let the Nessie from Posch Performance work on the M244.

Test bench diagram NESSIE - POSCH exhaust on Quattrini as PDF:

Test bench diagram NESSIE - POSCH exhaust on Quattrini as PDF: M244_1_POSCH_NESSIE

Until just before 6500rpm, the world is pretty fine for the Nessie. Then the curve takes a course that suggests that the Nessie would like to see significantly more outlet angles.

Nevertheless, the Nessie with 34.8Nm at approx. 6000 rpm can already be counted among the clearly high-torque systems.




Of course we also tested the Racing Resi from Posch Performance.

Test bench diagram RACING RESI- POSCH exhaust on Quattrini as PDF: M244_1_POSCH_RAC_RESI

The Racing Resi from the same manufacturer runs very similar to the Nessie and also requires more ventilation over longer control angles. With almost 35Nm at 6100rpm, the Resi is also well ahead in the league of absolute torque animals.



The Lakers as a thoroughbred racing exhaust, stands well in the feed despite the high performance and engine speeds to be expected with the low control angles.

Test bench diagram KINGWELLE LAKERS exhaust on Quattrini as PDF: M244_1_LAKERS

With almost 36PS at 7700rpm, it is the front runner in terms of performance in this expansion stage.
In the later expansion stages, when higher control angles and a wider outlet come into play, this exhaust can probably live out much better.


Overview test run 1 Quattrini M244 exhaust systems

Quattrini cylinder M244 in the first construction stage, M244_1 "Plug & Play" without further changes only with spacers on the cylinder head and on the cylinder base on the Malossi engine and Kingshaft crankshaft adapted.

Exhaust comparison overview Quattrini M244


Be curious to see how the second expansion stage will continue ...

Alex builds a Quattrini engine

Vespa Quattrini M244 engine 252ccm - from super tourers to top racers

The story of the Quattrini cylinder

Towards the end of 2015, rumors grew that Max Quatrini launches a potent cylinder for the PX200.

The time has come at the beginning of 2016. The M232 and the big brother M244 are available on the market.

A construction that took some getting used to seemed to follow the concept, a cylinder with a maximum bore of 72mm in the M244 and without a supporting cylinder base.

Due to the design of the crankshaft by Quattrini, with a connecting rod of 126mm, which is rather long for the Vespa engines, the piston does not work so deep in the engine housing and therefore does not need a long, classic cylinder base.

Today, in 2021, the cylinder is enjoying increasing popularity due to its very high torque values ​​and the smooth-running design thanks to the long connecting rod of the Quattrini crankshaft.

Reason enough for us to build an engine with it and play through many possible scenarios for you and see what comes out of it. We have tested exhaust systems and carburettors for you in various stages of expansion.

In the delivery note attached here for our technology department, you will find all the components that we have used for this engine and that, in our opinion, function permanently with this concept.

200 test runs on our test bench

In total, we have over 200 test runs with the Quattrini M244 Completed on our P4 test bench with various engine expansion stages. We have more than 50km measured runs documented and almost 20 liters of fuel burned.
We would like to share the experiences gained from this test with you in this blog series.


Quattrini Vespa Motor - All Parts


To select the parts:

The high torques to be expected from the M244 speak in favor of a reinforced motor housing.

The experience from many kilometers on the road with our own scooters has taught us that engines in the range from 22 to 25 HP can be implemented as "durable" in conjunction with a Piaggio engine housing.

Our M244 Quattrini cylinder but should be expanded a bit in the course of the test. This is why the choice here is a motor housing from Malossi with membrane inlet.

A Displacement of over 220ccm at erhigher engine speed, can no longer be supplied with sufficient fresh gas via a classic rotary valve on the narrow Vespa crankshaft. That's why we choose this Malossi motor housing with membrane control .

We have one to make the fuel mix Polini 30mm carburetor used. In this experiment he stands for one Carburettor with 30mm bore. In the course of the tests, we also tried a PHBH30 in a counter-test. We will present the result of this in the following part of this blog series.

On the topic crankshaft we trust king wave. Here we find exactly what we are looking for to build a high-torque, smooth-running and durable engine.

The choice falls on one king wave with 62mm stroke and 128mm connecting rod. Due to the 2mm longer connecting rod and increased stroke, we have the opportunity to work with the control angles by moving the cylinder using spacers on the cylinder head and the cylinder base in the stroke direction. The longer connecting rod in connection with the weighty crankshaft also brings a significant plus in smoothness.

The stroke of 62mm results Cubic capacity 252,4ccm - already very promising to build a torque-oriented engine.

The ignition should keep our tourer running smoothly, so we chose the one here bgm ignition with the PX pole wheel with a mass of 2300g.

The performance of the 252ccm unit is controlled by a bgm superstrong Clutch, the bgm primary 25-62 and one bgm Transmission with the graduation 12-13-17-20 passed on to the rear wheel. The short, fourth gear on the auxiliary shaft keeps the most frequently used gear more stable. With one tooth less in fourth gear, the teeth become significantly wider in the tooth base and thus offer a significantly higher load capacity than the variant with a gear wheel with one more tooth.


Concept and test plan

The requirement for the test setup is that we work from a rather good-natured touring design to a sporty design. Just to be able to depict a section through the possible variants. As a starting point for the test series, we set a basis with small control angles in order to be able to test as many sensible variants as possible later

To determine a starting point, the crankshaft is mounted with bearing dummies and the cylinder is attached to determine the control angle.

Based on this initial data, we can consider the extent to which we can set up the cylinder sensibly with spacers and also edit the outlet in later expansion stages.

After measuring back and forth a bit, we decide to start from the middle position of the control angle with one Transfer angle of 124 ° and a Outlet angle of 177 °.




Assembling the engine

Dream team: Malossi | bgm PRO | Kingwelle | Quattrini

The brand new Malossi motor housing will be finished by king wave for the crankshaft with 62mm stroke and the enlarged diameter of the crank webs with 99,4mm. The bearing seat for the bearing on the alternator side is also checked and reworked in individual cases, as the bearing seat is manufactured by Malossi with a very tight tolerance.

We also offer the completely machined housing with a high-quality crankshaft from Kingwelle as a set. We use the set for this engine KWM46228.

The one attached by Malossi Bearing Kingwelle does not recommend 6205 for the alternator side. We follow Kingwelle's recommendation and use a here NU205.

Before inserting the bearings, we process the motor housing and adapt the cylinder and the overcurrent ducts to each other. On a Piaggio engine case, this tends to degenerate into an evening event. The Malossi housing is already designed for the channels of the Malossi Sport and MHR cylinders and requires little rework for the Quattrini M244. Most of the work goes into removing the sealing surface on the cylinder base, which allows the M244 to be used on Piaggio engine housings.

Adjusting the transfer channels to the motor housing is done quite easily. The cylinder base seal shows how little needs to be adjusted here.

All bearings are traditionally used by shrinking in order to avoid damage to the bearing seats by simply pulling in the bearings. The shrinking or cold / warm process offers the advantage that no mechanical stress acts on the surface of the bearing seats and the seat is not widened as a result.


Wandering Malossi engine cases

Another peculiarity of the Malossi motor housing is that the supplied original silent rubbers are too narrow for the motor housing. Or rather, here Malossi has simply oriented the seats for the silent rubbers deeper in the housing than was originally the case. This allows the motor housing to move over the silent rubbers in the direction of the frame.

We have been here with one quite a while ago Spacer set BGM7952SP A remedy was created for the silent rubbers and thus ensured a secure fit of the silent rubbers in the correct position.

The gear

The M244 with a 62mm stroke of the king shaft brought to 252ccm, will transfer a lot of torque to the rear wheel. A guarantee to achieve a high cruising speed at a reduced speed. That enables the primary. Starting from a massive and early onset of torque mountain, the primary can be selected to be long or even very long. With 25 to 62 teeth, we use the longest primary offered by bgm. The reinforced primary repair kit from bgm creates a durable primary drive.

Shift pins and crossbar are included threadlocking assembled.

The bgm secondary gear is set with the smallest possible clearance with the bgm shoulder rings.

Assemble the Malossi motor housing

Further adjustments to the motor housing are no longer necessary and all other innards find their way into their place.

To assemble the crankshaft, the shaft sealing ring is moistened with a little oil so that the sealing lips slide cleanly onto the crankshaft and are not damaged.

The Malossi engine case, contrary to the Piaggio engine case, is without a solid seal composed. Instead of the paper seal, as in a modern engine concept, the housing is also included Surface seal sealed.

To connect the housing halves, M8 hexagon socket screws are used at Malossi. Due to the different lengths of the screws used, it is helpful to take a look at the Application listto find the correct attachment point.



bgm PRO Superstrong clutch & King shaft

The King Shaft is supplied with its own thrust washer and special key. The thrust washer has a clear radius that fits exactly to the radius of the crankshaft. A breaking thrust washer is almost impossible.



The Kingwelle has a special feather key on the drive side, which is specially manufactured for Kingwelle and fits exactly into the groove of the coupling hub.

We use one as a coupling bgm Superstrong CR a. With the standard equipment, 10 bgm springs XL, the CR clutch manages a reliable transmission of power up to 40hp. The coupling nut of the Kingwelle has a fine thread of the dimension M12x1. The nut comes with a screw lock and a Tightening torque of 70Nm attached.


Assembly of further components

The engine is then completed with the rest of the components.
Intake manifold with the Malossi 2-valve membrane. Clutch cover, switch latch, cover for the starter motor and the bgm ignition system with static ignition timing.

Stress-free assembly of the ignition base plate on Malossi engine housings

The Malossi motor housing is reinforced in many places. This can lead to contact between the base plate and the bearing seat when the ignition is installed. The base plate of the ignition must sit tension-free in the centering, so in individual cases the base plate and / or the motor housing must be slightly reworked to ensure a tension-free fit of the base plate.


Check crush dimension

Before the final assembly of the cylinder, we check the squish size with tin solder.
Due to the increased stroke, we aim for the squeeze dimension in the range from 1.3mm to 1.4mm and set this using the enclosed cylinder base seals.

By compensating for the larger stroke, there is no need for centering on the cylinder head. For this reason, holes for fitting sleeves are made in the cylinder head and cylinder. The adapter sleeves prevent the spacers used for the cylinder head in the course of the test from protruding into the combustion chamber and causing unwanted damage there.


The new Quattrini engine on the test bench

For the test runs, we set the ignition to 19 ° BTDC.

The runs of the first expansion stage We will introduce M244_1 to you in the next blog post before…

Just a quick note - none of the runs were below the 30PS Mark on the unprocessed M244











Vespa Wideframe Tuning

bgm SUPERSTRONG Vespa Wideframe GS

The proven bgm SUPERSTRONG clutch is now also available for the Vespa GS150 / GS160 and SS180 models.

bgm SUPERSTRONG clutch Vespa Wideframe

Ready-to-install coupling for your Wideframe Vespa

The bgm PRO coupling is delivered ready for installation. The scope of delivery includes

  1. the assembled coupling,
  2. a new lock washer,
  3. Clutch cover gasket and
  4. Crescent wedge

We also recommend the same Pressure plate and the separating mushroom to replace, available here in a practical set!

The Superstrong GS coupling replaces the serial coupling of the GS / SS models 1: 1 and can usually * be used without further modifications. The clutch is available with 22 teeth (like original) or with 23 teeth (longer stocky). Helical teeth for use with the standard 67-tooth primary gear.

The bgm SUPERSTRONG 2.0 Ultralube coupling combines:

  • extreme durability,
  • absolute reliability and
  • easy operation

It is the foundation of any solid Vespa engine tuning. The CNC-manufactured clutch basket has excellent concentricity and extremely high torsional rigidity. The Vespa clutch thus offers perfect coupling behavior with a clearly defined grinding point and clean separation of the clutch linings.

It is suitable for that Touring riderwho values ​​high quality, as well as ambitious ones Racer, the one extremely resilient and stable coupling .

Vespa Wideframe Tuning


The latest generation of Superstrong clutches now has an innovative new technology: Ultralube.
Ultralube pumps (through precisely defined bores and centrifugal force) transmission oil both into the highly stressed hub profile (between clutch basket and clutch hub) and onto the clutch linings themselves.
This in the Vespa area unique technology makes the legendary Superstrong 2.0 clutch even more stable than it already is. A clutch designed to last.


The ready-to-install clutch is designed for a power range up to approx. 20PS / 22Nm by means of the mounted clutch springs. Reinforced springs (sold separately, bgm PRO XXL Reinforced clutch spring) expand the performance range of the clutch to over 40 hp. It is still easy to operate.


The scope of delivery includes the complete ready-to-install clutch with bgm PRO Cosa clutch facings and ten BGM PRO XL springs. A new O-ring for the clutch cover and a new crescent wedge are also included.


We also recommend a low-alloy gear oil of classes API GL3 / GL4 for high-performance engines in order to prevent the clutch from slipping even under extreme loads. This also applies to our bgm Superstrong couplings. The old engine oil specification SAE30 corresponds to today's transmission oil specification SAE 85W / 90. We recommend this as a lubricant bgm PRO Street gear oil (BGM2025, corresponds to specification API GL-3).

* In some cases it may be necessary to rework the clutch cover and arm, see Instructions & Video:

Instructions for installation and adaptation

You can also find the installation instructions here: Instructions

Tool list:

TIPP: Toptul tool

  • Ratchet; SW10
  • Slotted screwdriver sizes 5 to 6
  • Ratchet; SW14
  • Open-end wrench SW19
  • Torque wrench up to 100Nm
  • Clutch holding tool
  • Clutch puller

Item list, alternatives and accessories

bgm PRO Touring Alu Vespa Clutch Lining Cosa

Vespa Cosa clutch plates bgm PRO Touring Alu

bgm PRO Touring Alu - our new clutch linings from bgm PRO - now retrofit a Vespa Cosa clutch with the properties of the Honda CR80 clutch linings

The bgm PRO Touring Aluminum facings are greatly improved clutch discs for all Cosa clutches. Revolutionary clutch linings in the Honda CR80 style with significantly more surface, but that Plug & Play fit into the normal Cosa couplings!

bgm PRO Touring Alu Vespa Clutch Lining Cosa

Clutch linings BGM PRO TOURING Alu type COSA2

  • Perfect symbiosis of racing technology and reliability for touring riders
  • Suitable for all conventional Cosa2 clutch baskets (strap width as original, 14mm)
  • Aluminum carrier material with reinforced contact surface on the tabs
  • Sinter pad material such as Honda CR80 in a wide design

The bgm PRO Touring aluminum pads combine the advantages of the popular CR80 racing pads with the high demands of touring riders.

Buy clutch linings here

Vespa Cosa clutch upgrade


The linings use an aluminum carrier, the lugs of which have a large contact surface for the clutch basket. This makes the coverings very stable over the long term. The slow shearing of the tabs, which often occurs with conventional decks with steel girders, is completely eliminated due to the large contact surface. The aluminum also makes the coupling more thermally resilient. This is a great advantage in extreme situations (e.g. starting with a heavy load on a steep mountain pass), but also offers a reassuring reserve in everyday life. The width of the flaps is made to fit precisely, so that the pads are almost free of play in the basket.


The lining material for the clutch discs is the same for the bgm PRO TOURING aluminum linings high quality sintered material as used for the CR80 racing pads. Due to the larger contact surface in the TOURING variant, the coupling is softer and not aggressive. The large support surface also improves durability.

Vespa clutch facing Cosa



The bgm PRO TOURING aluminum clutch linings are available as 1: 1 replacement for conventional Cosa2 clutch facings designed. They harmonize perfectly with the standard steel discs.
The thickness of the pad package corresponds to that of the original, which means that no shims or spacers have to be used. The pads fit into all serial clutches of the Vespa Cosa2 models, into the PX125-200 models from year of construction 1998 as well as into all vehicles that have been retrofitted with a Cosa2 clutch. The linings are also compatible with clutches / clutch baskets based on the Cosa2 technology, e.g. clutch –SC-, MMW, Scooter & Service or Ultrastrong.  (Strap width as original = 14mm)



The pads are not suitable for clutches / baskets that have been specially manufactured to hold the CR80 clutch pads, e.g. BGM PRO Superstrong 2.0 CR80, ONKEL MIKE 'DDOG' CNC or similar (strap width CR80 = 16mm)


The set includes:

  • 1x clutch cover plate (one-sided covering)
  • 3x clutch friction disks (facing on both sides)

Sufficient for a Cosa2 coupling.

CONCLUSION: The BGM PRO TOURING aluminum clutch linings are an ideal upgrade for your Vespa Cosa2 clutch.

Buy clutch linings here

bgm Tuning Lambretta

bgm Tuning Lambretta Highlights available again

Suitable for the new one bgm catalog 2018, are now two bgm Tuning Lambretta Essentials back in stock. Our 225cc RT cylinder and the Lambretta Superstrong clutch with 46 teeth, which harmonizes very well with the cylinder, are now available again:

bgm Racetour 225 Lambretta cylinder

bgm Tuning Lambretta cylinder -BGM PRO MRB-Racetour 225 cc- Lambretta TV 200, SX 200, DL 200, GP 200.

Mark Broadhurst has incorporated his experience from several decades of Lambretta tuning and over 1.700 tuned two-stroke cylinders into the development of the RaceTour cylinders. The bgm Tuning Lambretta cylinders are available with 195ccm (65mm bore) for the small engine cases with 125-175 ccm and with 225ccm (70mm bore) for the 200ccm engine cases.

Buy Lambretta cylinders here

Read more

The cylinders offer significantly increased performance and thus more suitability for everyday use and driving fun.
The power is available relatively early in the rev range and the kits have enough torque to drive longer gear ratios. The power delivery is very even, so that RaceTour engines feel like an original Innocenti 200 engine but with twice the power.

Like the original cylinder, the carburetor is on the left-hand side. No changes need to be made to the frame or the add-on parts. This makes the RaceTour the ideal cylinder for everyone who doesn't want to change the look of their Lambretta, but still doesn't want to forego performance.
All required seals, stud bolts and small parts are included in the scope of delivery.
Update: Pistons now from Meteor (made in Italy) with run-in coating.


  • Ceramic coated aluminum cylinder
  • Quadruple screw connection at the outlet
  • 200 ccm stud spacing for the intake manifold in the version for small and large engines
  • Piston: Meteor (made in Italy), with drive-in coating (RT195 = Ø65mm, RT225 = Ø70mm)
  • Piston rings: 2x1mm (made in Italy)
  • Solid, completely CNC manufactured head with recessed combustion chamber. Eight-fold screw connection. Made in Germany.
  • Compression ratio for maximum reliability when used with both 58 mm and 60 mm strokes.
  • Porting layout for high cruising speeds, lots of torque and a wide range of power
  • The purchase price is refinanced through the moderate consumption values
  • There is sufficient material on all sealing surfaces and channels to machine the cylinder to the maximum

Show installation instructions as PDF: bgm-Racetour-Cylinder-Installation-Instructions-BGM2225N

bgm Superstrong clutch Lambretta 46 teeth

bgm Tuning Lambretta clutch -BGM PRO Superstrong 6 discs, 10 springs- Lambretta LI, LI S, SX. TV (series 2-3), DL / GP -

BGM PRO Superstrong - the original
Extremely resilient coupling, very easy to use - Made in Germany
The Superstrong coupling combines extreme durability, absolute reliability and easy operation.
It is the basis of any solid engine tuning.
The massive, CNC-manufactured clutch basket has excellent concentricity and extremely high torsional rigidity. It thus offers perfect coupling behavior with a clearly defined grinding point and clean cutting. It can be used by touring riders who value high quality, as well as ambitious racers who are looking for an extremely resilient and stable clutch.

Buy a Lambretta clutch here
Read more

The ready-to-install clutch is designed for a power range up to approx. 8010PS / 20Nm by means of the mounted soft clutch springs (BGM25W). Reinforced springs, which are available separately, extend the performance range of the clutch to over 40 hp. The following spring types are available:

  • BGM8010W - soft (k = 4,7N / mm)
  • BGM8010L - medium (k = 6,8 / mm)
  • BGM8010F - hard (k = 13,8 / mm)

The bgm Pro Superstrong replaces the conventional coupling type used in the entire Lambretta LI vehicle family. Thus suitable for Lambretta LI, LI S, SX. TV (series 2-3), DL / GP models.

All CNC machined parts of the coupling are made of 42CrMo4.

The scope of delivery includes:

  • CNC rear sprocket with either 46 or 47 teeth
  • CNC clutch spider
  • CNC pressure plate
  • Adapter to use the pressure plate with both Li / SX and dl / GP motor cover
  • CNC machined cover plate with shoulder to ensure sufficient air between the cover plate and the kick starter shaft
  • Six clutch discs
  • Five 1.5 mm steel discs
  • Ten clutch springs, BGM8010W (k = 4,7N / mm, soft)
  • bgm PRO coupling socket

The clutch pressure plate and spider can also be used with all other five- and six-plate clutch pinions. As long as the pinions are within the Innocenti tolerances, this fits without reworking the parts. With such combinations, the protrusion of the coupling spider in particular should be checked.

 Also order the shim for spacing the coupling. This is installed under the clutch pinion and is available in thicknesses of 0,8-1,6 mm. The protrusion of the BGM hub (coupling spider) to the BGM pinion is in the tolerance range of 0,10mm to 0,12mm. A sufficiently large distance is set using thrust washers of various thicknesses. If the distance is too small, the clutch does not run freely.

Show installation aid as PDF: bgm-superstrong-assembly-aid-bgm8011nr46



Clutch centering aid -BGM PRO, Lambretta Superstrong- LI, LIS, SX, TV (series 2-3) - can only be used with BGM8011 article no. BGM8011TL2

Assembly aid for Lambretta Superstrong clutch

For our BGM Superstrong Lambretta clutch, we can now also offer the right centering aid for inserting the springs.

With the centering aid BGM8011TL2 it is very easy to position all springs in their place of use during assembly.

The clutch with built-in clutch compressor system

The BGM Superstrong for Lambretta already has a "built-in" clutch compressor system.

The coupling comes with two screws and long nuts for this purpose.
On the face of the coupling spider, two of the legs are marked with a point, at the bottom of which is the threaded hole for the screw.

Fully practical - and very easy to use:

The screws for pre-tensioning the base plate are threaded in here.

The cut-out in the centering aid exposes areas for the tall nuts, which are used to preload the coupling for assembly.


Very simple: as soon as the coupling is pre-tensioned, the centering aid can simply be pulled out.




super strong

Superstrong - the bgm PRO clutches for Vespa and Lambretta

Bgm - this is the brand of Scooter Centers, the word has got around so far and is no secret - on the contrary. In 2017 we are celebrating 25 years Scooter Center and all of our experience and know-how flows into our bgm products. We are proud of bgm and ours Superstrong clutches.

The highlights in product development were certainly the

Superstrong - the label keeps what it promises

The bgm PRO coupling is THE plug & play solution - Made in Germany.

Vespa bgm PRO Superstrong smallframe Clutch Made in Germany


The superstrong Clutch united

  • extreme durability,
  • absolute reliability and
  • easy operation.

The massive, CNC manufactured clutch basket offers excellent concentricity and superb torsional rigidity. It thus offers perfect coupling behavior with a clearly defined grinding point and clean cutting. It can be used by touring riders who value high quality, as well as ambitious racers who are looking for an extremely resilient and stable clutch.

Vespa clutches available

bgm PRO SUPERSTRONG couplings are back in stock

Here you come directly to the Superstrong couplings in the Scooter Center Shop


Vespa clutches available

Our best Vespa clutch is back in stock

In time for the summer season is ours bgm Superstrong clutch for the Vespa Largeframe Models available again. The robust and reliable coupling is so popular that we were unfortunately sold out at times.

New generation of friction disks for the Vespa clutch

From now on we deliver the bgm superstrong and the Superstrong CR with a new generation of steel discs. Did you know that the steel discs should be installed in a certain order?

Vepsa Superstrong clutch for Vespa Largeframe P1390241

Vepsa Superstrong clutch for Vespa Largeframe P1390241

The new clutch is each disc is clearly markedso that it is always clear in which position it should find its place.

bgm Superstrong - new friction discs for the Vespa clutch

bgm Superstrong - new friction discs for the Vespa clutch

All lenses have been redesigned and the fit has been optimized.

The disc at position two was given a defined curvature in a specially designed radius so that a clean separation behavior is achieved under every load condition when the clutch is operated.

The steel disks are subject to series testing, during which we always keep an eye on the concentricity and the planar quality, as well as the material quality and hardness. All steel disks are here in the 10hrc range.

Except for the optimization of the steel discs, nothing changes in the proven and stable concept of the Superstrong clutch for Vespa PX, T5, Sprint, Rally etc.


bgm pro superstrong honda cr vespa

NEW: clutch bgm PRO Superstrong “CR” for Vespa

Our 1000 times proven bgm PRO Superstrong clutch for the Vespa Largeframe-Engines received an update.
In the version "Superstrong CR”The CR clutch facings can be assembled without machining.




Pre-assembled coupling available

Only the upper surface is specially processed and offers space for the reinforcement of the cover plate.
Nothing changes in the mere assembly of the coupling itself.

Super strong CR 045

Easy construction

As a rule, as with the Cosa version of the Superstrong, it is sufficient to machine the clutch cover.
The necessary Information about this you can find in Article download area in our shop.


Super strong CR 040

The clutch basket of the CR version has not increased in outer diameter.

We only changed the contour so that the CR pads fit without machining.

Super strong CR 038
All other components such as the hub, pinion and steel disks are identical to those the Superstrong Cosa version.

New Vespa clutches:

The Superstrong CR is available in the following versions:

Plug & Play

Vespa PX80/PX125/PX150/Cosa125/Cosa200 (the large primary gear has 67 or 68 teeth)

Vespa PX200 (the large primary gear has 65 teeth or the BGM primary gear has 64 teeth)


Alternatively, you can of course also put together your own CR coupling.


Recommendation for torque monsters

For high-torque motors, we recommend that you change the Primary gear to 64 teeth also a reinforced repair kit. The stronger springs offer better shock absorption and mechanically digest the higher torque of the Monster motors better than their series counterparts.


Advantages of the CR rubbers

We have the advantages of CR pads on powerful engines in Contribution of the covering sets already mentioned. Here is an excerpt from it again:

"Why can such a small, flat clutch lining work better than the larger cork lining?"
In addition to the lining material with a better coefficient of friction, the keywords here are “effective radius”.
The decisive factor is the outer diameter in connection with the height of the covering and the resulting radius.

Pad set Honda 012

This means that the lever arm facing the torque acting on the hub is longer with the same outer diameter because the center of the lining is further away from the pivot point of the shaft. In the end, the simple law of leverage. It is therefore “easier” for the clutch lining to cope with the torque introduced. So he literally sits on the longer lever.

On the one hand, it is the common, ubiquitous physics and, on the other hand, the type of lining material that enables a clutch with CR linings to transmit a higher torque with the same pressure of the springs.

A CR pad set enables a clean and freely separating clutch with very little lever travel. The lining material also enables very simple and safe switching operations at high speeds.

Gear oil for clutches with CR facings

We recommend an oil with the specifications Jaso MA / MA2 or API GL-4 as a lubricant for these clutch linings.
For example that Valvoline 10W40 MA2.

Oil -VALVOLINE 4T- 4-stroke SAE 10W-40 mineral

Upgrade for the Vespa Cosa2 clutch types!

More power, more torque, more everything ... This is what the new Malossi MHR221, Quattrini M232 & Co. motors offer.
The concentrated torque of these units has to reach the road somehow.
One of the most important interfaces between the steam hammer and the road is also the coupling.

Super strong CR 050


She has one of the toughest jobs to do in the engine. On the one hand, every little bit of torque should be transmitted to the transmission with as little loss as possible and, on the other hand, reliability, durability and ease of use should be a matter of course.

Up until now, the rule that applied to Vespa clutches was that the more power you want to keep in check, the higher the spring strength you have to choose for the cork clutch linings.
Such an “improved” clutch, however, often requires almost Herculean effort to operate. The clutch lever is really just incredibly difficult to pull - so no real solution either ...

In order for the coupling to reliably provide propulsion over the long term, the spring force would have to be increased at engine outputs of over 35 HP and the resulting torque in such a way that the surface pressure of the cork coverings reaches its limits.
The natural material cork begins to behave like a sponge at high pressures and thereby influences the grinding point and the behavior of the clutch. The material is simply overwhelmed by the plastic deformation, the acting torque and the mechanical load during sliding friction. If the cork material has slipped under such a high load, i.e. the clutch has slipped, the surface of the covering burns and the material can no longer build up adhesion to the steel disc.

Pad set Honda 002

But how do you get a well-functioning clutch with low operating forces and a high level of transmissible torque?
The only remedy here is a different pad material with a better coefficient of friction and a trick from physics ...

Pad material from the motorcycle sector is considered to be very resilient. Unfortunately there are no pads here that would fit directly into a Vespa clutch.
That's why we have clutch linings machined to match, which are used, for example, in the VFR400 and the Honda CR.

Due to the processing, the clutch linings without further changes to the existing components in the well-known Cosa couplings.
The upper lining has to take on the task of the cover plate like a normal Cosa coupling.
This covering is also machined on the upper side so that there is space for the circlip.

Pad set Honda 005

The lining package itself and the necessary processing change the overall height of the lining package. The CR rubbers are a bit flatter in the package than the original Piaggo cork rubbers.
In order to compensate for this dimension and to give the upper surface more stability, a washer can be inserted as reinforcement at this point.
When retrofitting a Superstrong or a conventional Cosa coupling, it must be checked in each individual case whether this washer is absolutely necessary as a spacer.

Super strong CR 045

Pad set Honda 003

The base of the CR coverings is made of a high-strength aluminum material and is much thicker than the steel base of a conventional cork surface.
This fact helps the noses to be more resistant to knocking out on the clutch basket. However, if the springs of the shock absorbers in the primary drive are broken or slack, even wide noses on the clutch linings will not help. The force peaks are passed on to the clutch unhindered. One remedy here reinforced shock absorber set.

The stronger noses of the CR clutch linings also lie on a larger area in the clutch basket of the “Cosa variant” of the Superstrong.
In comparison here with a Piaggio Cosa surface. On the left the adapted CR clutch lining - on the right Piaggio Cosa.

Pad set Honda 008

When looking at the CR pads, however, one clearly asks: "Why can such a small, flat clutch pad work better than the larger cork pad?"
In addition to the lining material with a better coefficient of friction, the keywords here are “effective radius”.
The decisive factor is the outer diameter in connection with the height of the covering and the resulting radius.

Pad set Honda 012

This means that the lever arm facing the torque acting on the hub is longer with the same outer diameter because the center of the lining is further away from the pivot point of the shaft. In the end, the simple law of leverage. It is therefore “easier” for the clutch lining to cope with the torque introduced. So he literally sits on the longer lever.

On the one hand it is the common, ubiquitous physics and on the other hand the type of lining material that enables a clutch with CR linings to transmit a higher torque with the same pressure force of the springs. The lining sets are suitable for every Cosa 2 coupling. An existing superstrong can also be easily retrofitted or put together yourself.

A CR pad set enables a clean and freely separating clutch with very little lever travel. The lining material also enables very simple and safe switching operations at high speeds. We recommend an oil with the specifications Jaso MA / MA2 or API GL-4 as a lubricant for these clutch linings.
For example that Valvoline 10W40 MA2.

The pad set is available with and without steel washers:

If you are converting a normal Cosa clutch, we also recommend a set of reinforced springs:

BGM8800A - Clutch spring set -BGM PRO XL- Vespa Cosa2 - 8 pieces

BGM8801A - Clutch spring set -BGM PRO XXL- Vespa Cosa2 - 8 pieces




















New Lambretta clutch MADE IN GERMANY

The bgm super strong A new family is growing Lambretta clutch.

With the BGM Superstrong coupling for the Lambretta GP and LI models we can now offer you a clutch for your Lambretta with sprockets 46 and 47 teeth.


The scope of delivery includes the complete clutch kit with 6 disks and 10 springs, including the pressure plates for the Lambretta GP and LI / SX gearbox cover.

lambretta coupling made in germany

Lambretta clutch with 6 discs

Clutch linings, steel plates and springs

Lambretta Superstrong clutch plates BGM8006


Lambretta clutch with 10 springs

With the 10 bgm PRO XL springs and the bgm 6-disc clutch linings a very high torque can also be transmitted with a very short reduction ratio from pinion to sprocket: Mathematically up to 60Nm.

By the use of ten feathers you have a lot of options to determine the perfect selection of spring force for your engine.


Chain wheels with 46 and 47 teeth

With the sprockets you have the choice between 46 teeth and 47 teeth.

Due to the very open design, the sprocket remains very light and enough oil can penetrate to the coupling socket at any time.
The flanks of the sprockets are lengthened to give other combinations of clutch linings and steel disks enough space.

Together with the bgm pinions you can put together your own individual gradation depending on the gearbox.


Lambretta Superstrong clutch BGM8011R46 (4)


Coupling spider, base plate and cover plate

In order to ensure good operability, the coupling spider, the base plate and the cover plate have been completely reconsidered.

The coupling spider has been lengthened and the flanks have been adapted to the base plate. This guarantees good ease of movement even under high impact loads without the base plate tending to set. This effect is further reinforced by the 10 springs evenly supported.

The overhang of the coupling spider to the chain wheel is a maximum of 0,1mm. By maintaining this low tolerance and by using the BGM coupling socket, clean and good guidance of the sprocket is permanently guaranteed.


Built-in clutch compressor

Practical; the integrated clutch compressor.

With 2 screws you can easily change the pad or spring. Two screws are lighter and easier to stow away than the big brother from the workshop, especially for traveling on longer tours.

Lambretta Superstrong clutch with clutch compressor

Buy Lambretta clutch




Clutch spring bgm PRO XXL

Clutch spring bgm PRO XXL - strong pressure for Vespa clutches

The bgm Superstrong coupling family is getting a reinforcement!

By breeding ever larger herds of horsepower in the area of ​​Vespa Large and Smallframe Engines, the clutches are also subjected to increasing loads. In extreme cases, torque and power increase here over 50PS and 40Nm ...

So that you can always rely on the power transmission of our proven bgm clutches, we provide you with additional reinforced ones for extreme applications bgm PRO XXL springs MADE IN GERMANY to the side. The springs are available for Vespa Cosa clutches and bgm PRO Superstrong clutches.

Clutch spring BGM PRO XXL for Superstrong Vespa clutch BGM8801E

Like all bgm springs that we have produced in Germany, this spring is also made of Oteva70 © manufactured. A very resistant material from vehicle engine construction. The springs do not settle and are very durable.

We deliver the bgm PRO XXL springs galvanized. This way you can tell the difference to the

  • XL feathers in black and
  • XXL feathers in shiny silver

at a glance.

We can provide you with the bgm PRO XXL springs individually or in sets, suitable for your coupling type:

For normal Cosa couplings we offer a set with 8 springs. Each as XL and XXL variety.

For the bgm superstrong Largeframe Couplings a Set of 10 springs

and for the bgm superstrong Smallframe Clutch you can simply use 2 sets with 8 springs. With a set of 8 you even have the option to mix the springs (XL and XXL).

So then,

Torque GO!

The Superstrong coupling family receives in the large and Smallframe Growth.

For the Largeframe We equip the tried and tested models Superstrong with a 24 tooth DRT pinion off to the translation on an original 65 teeth primary gear to extend.

Especially with the current cylinders from Malossi and Poliniwhich provide a very high torque, it makes sense to lengthen the translation to convert the potential into speed.

bgm super strong 005

Im Smallframe Sector an additional coupling spider is suitably deposited for DRT auxiliary shafts in the Superstrong clutches offered. DRT auxiliary waves are a useful addition to almost all engine concepts in the SF area in order to adapt the transmission to a more sporty driving style. There are one here Variety of gradation variants to disposal. The auxiliary shafts offered by DRT are about 1,5mm higher.

Here the DRT variant:

04.12. 2013 021

and the regular version:

04.12. 2013 020

So that you don't become too strong Spacer for the clutch cover, we have adapted the Superstrong accordingly for this area of ​​application.

In order to keep the two variants apart, we have equipped the DRT version with a clearly visible collar.

On the left the regular version and on the right the DRT variant with collar.

04.12. 2013 025

Both couplings are available immediately.

vespa coupling BGM8099

Vespa clutch

[youtube] MJKxoBYbrbQ [/ youtube]

The bgm PRO Superstrong Cosa coupling is the plug n play solution - Made in Germany.

This quality Vespa clutch is with 20,21,22, 23, XNUMX and XNUMX teeth available: Vespa clutch

You get a ready-to-install Vespa Cosa clutch with the supplied reinforced clutch springs in a performance range of 20HP / 22Nm works fine.
With separately available springs with a higher spring rate *, the clutch can keep up with setups without complaint significantly above 30 PS and is still easy to operate.


  • One-piece CNC milled clutch basket - Made in Germany.
  • The extremely robust construction offers perfect and precise guidance of the hub thanks to the shaft teeth.
  • The hub is made of high-strength steel to prevent the hub from cracking.
  • Thanks to the use of ten springs, there is sufficient spring force even for high-torque setups with little effort on the clutch lever.
  • Clutch basket hardened by nitriding, worn out clutch baskets are a thing of the past.
  • Always precise cutting thanks to the pressed sintered bushing.
  • Every coupling is subjected to a quality control. In this way we guarantee that we will deliver a functioning and ready-to-install coupling.

The scope of delivery includes the complete ready-to-install clutch with bgm PRO Cosa clutch linings and ten reinforced springs. A new O-ring for the clutch cover and the crescent wedge.



The number of teeth on the clutch is important for the length of the total reduction. This can also be varied. Possible combinations:

  • Original 20 teeth: 21T, 22T
  • Original 21 teeth: 20T, 21T, 22T
  • Original 22 teeth: 20T, 21T, 22T
  • Original 23 teeth: 21T, 23T

For models up to and including 150cc, a small cast aluminum lug in the motor housing must be removed to mount the clutch. This can be easily snapped off with larger pliers. With some clutch covers, minimal material has to be removed from the drip nose at 12 o'clock in the area of ​​the radius.

The Vespam clutch can be installed in almost all engines of the so-called Vespa Largeframe Class. These are all vehicles whose chassis prefix is ​​three-digit (e.g. VNB, VNL, VNX etc., the addition 1T, 2T, 3T is not taken into account) and which have the carburetor installed directly on the engine housing (not in the frame or on the cylinder). On some old vehicles before the Vespa PX era, the thin washer (1,5mm) under the clutch has to be replaced with that of the PX models (3,3mm Item No. 7671297

* We use bgm PRO XL clutch springs:

Spring rate N / mm
Original Piaggio 4,0
Worb5 XL 6,2
bgm PRO XL 6,5
Worb5 XXL 7,1
Malossi 7,9
Worb5 XXXL 8,9

New Vespa clutch for Smallframe

After the success of the BGM Superstrong Vespa clutch for the Vespa Largeframes, we also have a solution for the Vespa Smallframes developed. Now in Scooter Center Vespa shop available

As with the Vespa clutch for the large engines, the Components made in Germany.

Brief overview:

  • Made in Germany
  • higher transmission power due to more surface
  • longer service life due to more material
  • Even contact pressure thanks to 16 bgm PRO XL clutch springs
  • perfect coordination option
  • Mobile with Vespa PK XL1 and PK XL2 cover
  • stable coupling hub with internal thread for standard pullers
  • extremely resilient, also for engines with 30HP +
  • Plug & Play coupling is delivered ready for installation
  • Spacer available

Superstrong - Extremely high performance

The clutch hub as well as the cover and thrust washer are made 42CrMo4 manufactured. The force is from bgm Racing red clutch plates transfer. The design of the clutch linings in the Vespa PK-XL / Vespa V50 version offers more space to transmit the torque. In this context, more material naturally also means a longer service life.
Vespa clutch bgm Superstrong for Vespa Smallframe

16 springs for even contact pressure

When it comes to springs, we use tried and tested methods. sixteen bgm Pro XL springs ensure even contact pressure.

Vespa clutch bgm Superstrong for Vespa Smallframe

Due to the number of springs and the arrangement on the largest possible extent, a very even pressure behavior is achieved. This effectively prevents the two pressure disks from tilting or locking.

Thanks to the perfect coordination of spring stiffness and number, paired with the stiff design of the pressure plates, the clutch can be operated easily even with a PK-XL1 clutch cover.
The contact pressure of the bgm Pro XL springs and the coefficient of friction of the Racing red pads have a Test in our X-Mas duel already withstood the 30PS.

vespaVespa clutch bgm Superstrong Smallframe

Highly stable & well thought-out coupling hub

The clutch hub is designed for a primary with a shock absorber and has an M28x1 internal thread for pulling off. (The extractors of the Vespa fan wheels with electronic ignition fit there.) Thanks to the internal thread, the area around the cone could be made much more massive. The more stable design without the senseless weakening by an unnecessary keyway makes the hub the first choice for every load. We recommend our for assembly Coupling nut and threadlocking. To dismantle the clutch or to change the linings in the engine, our bgm multitool BGM8819 should be used.

Vespa clutch bgm Superstrong for Vespa Smallframe

Plug & Play Ready-to-install delivery

We offer you the bgm Superstrong for the Vespa clutch for Smallframe Fully assembled with 4-disc bgm Racing red clutch linings and 1 mm steel discs.

Vespa clutch bgm Superstrong for Vespa Smallframe

For PK XL1 & XL2 clutch cover

The pressure plate is for holding a PK-XL2 pressure plate designed and can therefore be used on a PK-XL1 or on a PK-XL2 clutch cover.

Optional spacers available

Depending on the combination of engine housing, auxiliary shaft and clutch cover, it may be necessary to place the clutch cover underneath. For this we offer you a matching spacer set.

Matching Vespa models

(PK-XL1 or PK-XL2 clutch cover required)

  • Vespa 50 PK XL2 (V5N1T)
  • Vespa 50 PK XL2 HP (V5N2T)
  • Vespa 50 PK SS (V5S1T)
  • Vespa 50 PK XLS (V5S2T)
  • Vespa 50 PK (V5X1T)
  • Vespa 50 PK S (V5X2T)
  • Vespa 50 PK S Lusso (V5X2T)
  • Vespa 50 PK XL (V5X5T)
  • Vespa 50 PK XL Rush (V5X4T)
  • Vespa 50 PK N (V5X5T)
  • Vespa 50 PK XL2 (V5X3T)
  • Vespa 80 PK S (V8X5T)
  • Vespa 125 PK (VMX1T)
  • Vespa 125 PK S (VMX5T)
  • Vespa 50L (V5A1T)
  • Vespa 50N (V5A1T)
  • Vespa 50 (V5A1T - 1963)
  • Vespa 50 S (V5A1T - 1964)
  • Vespa 50 Special (V5A2T)
  • Vespa 50 Special Elestart (V5A3T)
  • Vespa 50 Special (V5B1T)
  • Vespa 50 Special Elestart (V5B2T)
  • Vespa 50 Special (V5B3T)
  • Vespa 50 Special Elestart (V5B4T)
  • Vespa 50 SR (V5SS2T - 1975-)
  • Vespa 90 (V9A1T)
  • Vespa 125 Nuova (VMA1T)
  • Vespa 125 Primavera (VMA2T)
  • Vespa 125 ET3 (VMB1T)