which ever motor you decide on you need to look at how you can connect the transmission to the rear end. if you mount it in the frame like bikes the transmission will line up with the middle of the rear axle. i know that the rear drive sprocket it connects to will need something to bolt to. i dont thonk they make one that is made to be part of an axle. at least i havent seen one. i think the suggestion of not using plastic rims is more for your safety. going over a bump when you are pedallonh a boke is way different than hitting a bump on a bike going 30 mph. even in my bike ive got a double spring fork setup that is pretty stiff yet i have a dent in my front fender from where the forks that generally dont move came up and hit the fender. not to mention it loosened some fillings in my teeth. if i were using plastic rims when i hit that the rim would have probably broke or worse. thankfully the only thing that happened to my bike was the dent on the fender. im also glad the bike came with heavy duty spokes. when you decide to start a project to motorize something that was originally made not to be, whether you are doing it for the first time or the tenth time your first and foremost concern HAS TO BE safety. not just for you when you are riding it but also for other people you are sharing the road with. You might cause an accident where you are hurt but there will more than likely be another person involved. ..i could be in a bunny outfit riding a unicycle and look cool...lol...
so looking cool has to always come after safety. i look good no matter what so i dont worry about it...lmao
you may think about an electric conversion. that woll give you more options on your set up. that way tou can use a front wheel drive motor that way it would be less of a problem. your biggest problem the would be how to run the wiring foir everything. or you can choose to ignore safety and do it how you want. if you do that al;l i ask is that when you are recooperating from a hospital bed you get on the site here and tell is how it went
