BGM Pro auxiliary shaft 'made in Europe' for Vespa Smallframe

BGM Pro transmission parts are ultra-solid material. The auxiliary shafts are manufactured in Europe from high-alloy NiCrMo case-hardening steel (14NiCrMo13) to withstand the highest loads.
The precisely machined, very tough and strong steel is then hardened at Thyssenkrupp and is therefore ready for maximum engine performance. To guarantee exactly this, BGM transmission parts are subjected to extensive series of tests.

TESTING LAB
Pulsation tests in a German testing laboratory, in which we compared the very stable old original Piaggio auxiliary shafts with our BGM prototypes, showed a 50% higher load capacity of the BGM PRO auxiliary shaft. The precisely defined surface hardening to 58-60HRC also makes the sprockets extremely resistant to wear. Better than Piaggio goods. Always consistently high quality. No compromises.

Application
Suitable for all types of use, whether tourer or hardcore racer.
They harmonize perfectly with the BGM PRO gear wheels for Vespa Smallframe.
The BGM PRO auxiliary shafts are available in three gradations:

STANDARD GRADING (BGM01822)
The standard gear ratios correspond exactly to the original Piaggio gearbox as used in almost all 50-125cc Smallframe engines ex works. Can be used with the original gears (Z 58-54-50-46) or (as an alternative to BGM01821) combined with a short 4th gear (Z 48).

SPORT GRADING (BGM01821)
BGM01821 is ideal for sportier setups that require a closer gear connection between gears 3 and 4. Here, fourth gear is one tooth shorter, which means that the engine is always perfectly in the power band when shifting from 3rd to 4th gear. Very popular when a strong resonance exhaust is used with a tuning cylinder.
A very good alternative to a short 4th gear (Z48) as fewer teeth always result in a more stable gearwheel / auxiliary shaft (wider tooth base). Is used with the original gear wheels (Z 58-54-50-46).

RACE STEP (BGM01720)
Here the third gear is already one tooth shorter, the fourth gear is already two teeth shorter. These short gear steps make it possible to always remain perfectly within the power band of a high-revving engine. For road use, this is usually combined with a longer primary reduction ratio to achieve a sufficiently high top speed. Gears 1-2 are then already correspondingly long and can already be used as full gears. Is used with the original gear wheels (Z 58-54-50-46)

FIT
The BGM PRO auxiliary shaft fits all smallframe engines with four-speed gearboxes.

EXCEPTIONS
An exception are the so-called moped gearboxes (so-called 'ÖAustrian gearboxes').
The Austrian mopeds have a longer secondary gearbox.
Here it is possible to convert to the BGM Pro auxiliary shaft if the gearwheels are also replaced. This transmission was also used in vehicles for other markets (e.g. Portugal).
Also excluded are the V50 1° series (V5A1T) vehicles with 1° series engine (V5A1M up to engine number 92876): These engines have a narrower engine housing and a narrower main shaft. Conversion is not possible here.

Conclusion: Very stable gearbox components with an excellent price-performance ratio