We can referred the 06-09 M109 as the first generation 109, and the 10-on as the second. What's difference between the two gens is not only in the redesigned tachometer but most importantly, the clutch system. We have learned that when entering first gear the impact of gears collision deteriorate significantly with the 10-on models. The inconvenience of shifting from first to second gear on the 06-09 models has been improved. The root of the problem lies on the five clutch plates in the old gens that when in motion, the friction between the plates are not enough without the bigger kg/m clutch spring, which is also the reason why we have to pull pretty hard when reaching the clutch lever. What's worse is that this clutch spring will experience elastic fatigue after consistent usage for two years. The second gens clutch system altered into six clutch plates to increase its friction and lower the kg/m of the spring. The result is easier and more comfortable when reaching the lever and longer lifespan for the clutch spring as well. Revo-cycles has successfully help many of our riders to upgrade their 06-09 models' clutch system into 10-on's.
2012 on the left, 2008 on the right
Although the OEM part number is different, both of them shares the same sizes.
2012 has become lighter
The clutch pressure disk on the outside is the same, so all you need to do is change the clutch plates, clutch driven plate and springs to finish the upgrade.
2012 on the left, with softer handling that is more comfortable for longer ride.