I recently had a Leo Vince pipe installed along with necessary jetting and more than doubled my horsepower at the rear wheel. This was verified on a dyno. Along with this, a Malossi variator was installed along with a racing clutch. The stock top speed was 27-28 mph on a level road with W.O.T. I can now cruise 30-35 mph with partial throttle, the bike easily does 40+ mph and holding W.O.T. long enough will hit 45+ mph. Moderate hills which used to slow me down are just the opposite now as I am accelerating on them. Also it was found that my compression was out of spec by ~ 24 psi, so once that is corrected, there may be a modest additional gain.