the chain was least of my worries lolthe engine sits a little close to my leg. i know to keep it away know since i already burned mydelf on it. i have 3 lines on my leg now from the engine fins. only did that once lol. i love driving the bike around i get such confused looks when i start peddling it. people always ask me about it when i stop. i try not to stop near to many people since it tends to slow me down lol. i have had it going about 40 so far but it can go faster. i need to change the gearing on the rear sprocket to make it go a little quicker.