Casa Performance have just released a new close ratio gearbox for Lambrettas. The ratios were chosen by Vittorio Tessera to offer a cheaper sporting alternative to the Cyclone 5-speed.
This all new, 4 speed gearbox is designed to fit any Lambretta Series 1, 2, 3 GP / DL or Serveta scooter. It uses a forging for the gear cluster and has been tested on the racetrack.
The gearbox uses an interesting set of tooth combinations which is similar to the old MSC close ratio, apart from 2nd gear:
cluster – loose gear (same ratio as) % rise
11-50 LI 150 1st
14-41 LI 150 2nd 55%
16-39 LI 125 3rd 20%
18-36 GP 200 4th 22%
Advantages of this gearbox are :
- Close, even ratio jumps of around 20% from 2nd to 3rd and from 3rd to 4th
- The same final drive ratio in 4th gear as a GP200 gearbox.
- Top gear will give approx.. 9.43 mph per 1,000rpm with 18×47 sprockets.
The last point is important because it means that you’ll need to run a big front sprocket (18T or more) with most tuned engine conversions.