I bought a Motorized bicycle engine kit from Bumblebeebolton and it was super easy to install. The entire kit is held on by one bolt! theres a total of 3 bolts on the entire kit and your ready to go. I put alot of miles on it these past few weeks and it has proven to be a very reliable kit. I have been riding motorized bikes for years and this is definatly the simplest and most reliable kit out there. my other kits are just collecting dust!