My hub project was fun:
Just got my electric kit from china
but I think next spring I'm gonna sell it off and start fresh. Been looking at the cyclone motor that runs inline with the chain (which other people have bought on this forum). Some buy the 500watt kit available from the american site, I think I'm going to buy the 1200watt kit directly from the Taiwan website:
I know most people complain that the derailluer pulleys wear out fast because it's a fast metal chain pulling on plastic gears. Did some research, and I'm sure I'm not the first one to discover this but they make ceramic bushing on aluminum alloy cogs:
$32/each isn't cheap, but not terrible. Did a search on ebay, some are selling a pair for $30. Metal chain on metal cog, and a ceramic bushing which can handle high speeds and high temperatures, should work out well.
For anyone that doubts the power of gearing, check out these videos:
75mph using dual 1500watt motors:
Climbing stairs like it's nothing :
With that said, there's definitely a sharp trailing off return as you approach high speeds. One 1200watt motor is rated at 45mph (for lightweights), it takes 2-1/2 times more power to bump that up to 30mph more. I'm sure it has to do with wind resistance. By the way, I don't intend on doing those speeds, my likely top speed will probably be 35mph. BUT, if I'm even going to be going that fast, I'm going to want to start with a bike that at least has disc brakes.