I think its my back tire im not sure, its only squeaky at low speeds when i get up to ten mph it stops and I never full throttled yet because the engine gets very loud and It sounds like im destryoying insides of the motor and I here the chain and freaks me out so I just go back to normal speeds about ten mph. I never go above 15 mph because after that the engine is very loud I want to full throttle without So I can see how fast my bike can go.