well the tires on my bike are a bit knobby but I want this bike to do at least 75mph with the right gearing. I know its possible
An L125 should give you 15-20mph beyond stock. Sorry to burst your bubble, but an honest 75mph requires more like 18hp...close to twice the output of a stock L125. Sounds to me like your bike has a generous speedometer and that's probably a good thing. The stock tires, brakes & suspension all run out of capacity around 60mph. A balanced 75mph bike, i.e. a machine that will reach that speed and not be a deathtrap, should have real brakes & suspension that are up to the stresses generated. That can be done, but it's a serious undertaking. 75mph is really "
carrying home the mail" on a CT70.
No 10" knobby tire has higher than a 62mph speed rating, the tread pattern doesn't have enough road holding stability for freeway speeds anyway. Stock K0 suspension, with those pogo stick fork legs, is just plain scary at speed.
The good news is that for most suburban areas, being able to maintain 50mph+/-5 is usually fast enough to keep up with traffic...and fast enough to feel like you're moving.:4: Make sure your fork legs are tight, if they aren't, new lower glides and upper piston slides are cheap enough; that'll give you reasonably stable steering. Upgrade your rear shocks to handle a rider weighing more than 120lbs. That'll give you max bang for your buck, a ~60mph bike that doesn't go into uncontrollable speed wobble or bottom-out from anything taller than an expansion joint.
