Primary transmission gear kit TOP RACING +21% 13/43 for 14-tooth countershaft

The Portuguese tuning specialists, Top Racing, are a symbol of high-quality scooter components. Thanks to advanced production techniques and over 50 years of experience, many European brands entrust their tuning to Top Racing. The relatively simple installation of the Top Racing transmission is another reason to look no further than this Portuguese brand.
To increase performance and speed, you need more power and a longer gear. Since most vehicles are factory-fitted with a very short gear, you should install a longer gear to protect the engine from over-revving and make use of higher speeds.
Top Racing transmissions are pre-pressed and ready for assembly. Simply replace the original parts and you’re done!
Not really suitable for 50cc cylinders. Fits Minarelli engines with an original intermediate shaft with 14 teeth.
Top Racing factory specification: Ratio 13/43, 21% longer than the original.
Tuned transmissions generally feature straight-cut teeth to reduce friction. This leads to slightly more noise, but is harmless.