nothing wrong with experimentation....and learning new things....
but most people will tell you if you already have a bicycle you like, its usually much better to buy a complete brishless hub kit and install it, then rig up a homemade kit using cheap components that will be inefficient and heavy in weight...
in other words, if you are serious about wanting a ebike, you could buy a complete front mount brushless hub kit , with battery/s , for around $400 - $ 750 and you would have a much more reliable, faster setup that will also go alot farther then the homemade 12 volt battery setups , in which you have to lug around a lead acid battery that weighs up to 40 lbs.....and thats only for a 12 volt system...
the current technology and low price point of premade brushless hub kits, almost make it totally absurd to try and build home kits out of weak brushess motors , friction drive systems and heavy 12 volt batterys.