I cant turn the lights off my derbi senda sm 125 cross city

SOURCE: i need to tighten the chain on my derbi cross city 125

looks like you have a nut at the rear of thr swing arm, one on each side, these are the rear wheel/chain adjusters. slacken the wheel nut and then adjust the nuts, there should be some kind of markings on the swingarm so you can get both sides the same. when done tighten the wheel nut and you are done

SOURCE: i want to have more horsepower

Hey. Replacing the stock cam with a performance camshaft will help. To gain more horsepower you should also make the airflow to the engine better. Replacing the stock sylinder with a big bore 150cc kit will sure make the engine more willing. The engine on a 08 Derbi senda baja model, is the same engine that you will find on a Yamaha TTR 125. So that is what you should search for. Hope it helps:)

SOURCE: Hi i have a derbi cross city 125 back wheel problem

You can get new wheels on ebay, or at your local motorcycle dealer, and it does not have to be the exact same tyre, but it does have to be the same hight, i would reccomend bridgestone tyres as they last a hell of a lot longer than the stock, well worth your money