Crankshaft -BGM- (rotary valve) 48mm stroke and 51mm stroke, 105mm connecting rod- Vespa P80X, PX80

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Crankshaft Vespa PX80 BGM031080G (3)

Crankshaft Vespa PX80

Many of you still know and may have discovered your love for the Vespa on this scooter:

The Vespa PX80, which was built by Piaggio only for the German market.

80cc - the German way

With the fall of the old regulation valid in Germany until 14.02.1996/80/80, 80ccm up to a maximum of 80km / h, the sale of the PXXNUMX in Germany was also discontinued. Unfortunately, the spare parts supply from Piaggio became very scarce. For a long time there was no alternative to the expensive, original and difficult to find Piaggio PXXNUMX crankshaft.

In the meantime, however, the PX80 has also stood out from the shadows behind the PX200, which is favored in Germany, and there is a loyal fan base for the smallest motor from the PX family.

Vespa PX80 tuning

With the appropriate components, however, the PX80 can again experience an enchanting second or third spring and catch up with the performance of its big sister.

Well-known friends are here “The 139er” from Malossi and “The 135” by Diffusione Ricambi, DR for short.

While Pinasco tried to add a shovel with the 149 aluminum cylinder, Polini never tried the PX80.

Vespa PX80 crankshaft - the weak point

Regardless of which cylinder was driving the unit of the PX80, the original crankshaft went the usual way: by losing the thrust washers and the resulting death of the lower connecting rod bearing, it quit its service - good advice was expensive.

The solution: our Vespa PX80 crankshaft from bgm PRO

You will learn from experience, which is why we have the easy-to-turn PX80 with our bgm PRO Crankshaft for Vespa PX80 donated a set of sturdy thrust washers.

With the bgm crankshaft there is finally a suitable replacement for the PX miniature motor.
With the bgm standard crankshaft with 48mm stroke, there is only a very slightly longer intake time.

Other crankshaft manufacturers design a much too large opening angle for the PX80, the result is that the cylinders with the small control angles in connection with the small inlet provided by the "anti-tuning bores" no longer run usefully in the lower speed range. The tunability of such motors also suffers due to the large opening angle.

Also available as a long stroke shaft Vespa PX80

So that screwing on the PX80 is fun again, we also have a "Long stroke version”Placed on the bgm crankshaft.

With 51mm stroke On the small engine, other performance values ​​can be achieved and the existing cylinders benefit from the increased control angles.


Order crankshaft for Vespa PX80 here

Comparison of long-stroke and standard shaft

Here is a quick comparison when using the different cylinders on 48mm and 51mm stroke.

Series stroke 48mmOutlet angle °Overcurrent angle °Advance °
Malossi 13918212031
SC conversion cylinder 125ccm15511022,5
Long stroke 51mmOutlet angle °Overcurrent angle °Advance °
DR135 + head gasket 1,5mm15812118,5
DR135 head gasket 1,5mm (+ 2mm outlet height)16812123,5
Malossi 139 head gasket 1,5mm18412629
Malossi 139 head gasket 2,0mm (foot -0,5mm)18212429
SC conversion cylinder 125ccm head gasket 1,5mm15811720,5
SC conversion cylinder 125ccm head gasket 1,5mm (+ 2mm outlet height)16811725,5


Tip: Pay attention to the correct translation

If the PX80 is equipped with a larger cylinder, the Primary reduction be changed.

The PX80 has the shortest version with 20/68 teeth. For the original clutch with 6 springs and a diameter of 108mm Clutch pinion available with 21, 22 and 23 teeth.

A clutch for life:

Alternatively, the entire clutch can be exchanged. Also the BGM Superstrong Fits into the PX80 after a few small changes and can be operated with the primary wheel of the 80s. Here, too, there are variants with 20, 21, 22 and 23 Teeth.

Vespa clutch bgm PRO Superstrong MADE IN GERMANY Cosa clutch Vespa PX


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