Shimming Vespa & Lambretta transmissions

Here we show you how to properly shim the Vespa transmission: shimming Vespa transmissions

In order to balance out too much free play in the gear box you need shims in the corresponding thickness. We have introduced these high quality BGM PRO shoulder rings for Vespa and Lambretta engines to our programme.

The hardened and grounded transmission shims generally have a tolerance of just +0/-0.04mm and during manufacture each batch is subject to comprehensive testing.

SI FasterFlow 004

Vespa shims/ spacers / shoulder rings

Vespa Rally, Sprint, VNB etc.

There is reason for enthusiasts of the older Vespa Largeframe models like the Vespa Rally, Sprint & Co. to be pleased: for these gearboxes, the fitting shoulder rings ranging from 2mm to 2.50mm are finally available again, thanks to BGM PRO.

The shoulder rings feature, as is the case for the stronger Vespa PX EFL version, 4 nibs for locking in. Hence, with the new production design it is no longer possible to chop off an individual nib.


We had the shoulder rings for the older 3 and 4 speed gearboxes (can be identified by the single shoulder ring that is required on the shifter bolt side) manufactured for you in standard dimensions.


Vespa PX EFL and Vespa Smallframe

For the Vespa PX EFL and Vespa Smallframe gearboxes we offer the shoulder rings in standard dimensions from 1.00mm to 1.40mm and additionally also in 0.9mm. This dimension is often required when converting the sprockets on the main shaft in order to restore the proper free play but also in case you wish to use the stronger circlips according to DIN.


The BGM PRO shoulder rings are hardened and ground parallely so that your transmission keeps the adjusted free play reliably and for a long period.

Vespa BGM PRO transmission shims
BGM PRO shoulder rings

  • hardened and grounded parallely
  • just +0/-0.04mm tolerance
  • available in many thicknesses
  • for a precise gear change
  • and a long lasting gearbox

Lambretta shims/ spacers / shoulder rings

For Lambretta gearboxes we can offer you transmission shims in different thicknesses as well. BGM6020_2

Gear box shim -BGM PRO- Lambretta series 1-3

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