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Old 03-12-2012, 03:31 AM
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a_dam a_dam is offline
Motorized Bicycle Elite Member
Join Date: Feb 2009
Location: Momence, IL
Posts: 349
Default Re: ON MY FIRST BUILD From Pearland , Tx

i will be using my bike to just cruise around so the most i would need out of it is about 40mph
HAH! Is that all? 30mph is fast on a bike. 40 must be scary. That motor might be able to do it. My connection is too slow to open that video to see what kinda bike you have (would be easier if you just tell us).

But a 26" bike tire at 40mph is 515 rpm. That motor has a 6-tooth sprocket. If you had a 60 tooth on the rear wheel, that would be 10:1 reduction. So your motor would turn 5150 rpm at 40mph. That's really not nearly enough reduction. At 15:1 the motor rpms would be 7725. That's not a bad rpm for top speed, but your rear sprocket would have to be 90 tooth. It aint gonna happen without a gearbox or jackshaft setup. (unless you do friction drive)

That's why most people here use bike motor kits. Even with a good kit you will have to be mechanically handy. Without a kit, you will REALLY have to be ready and willing to do a lot of "crafting".

But whatever route you go, if you are serious, then this is the right place to get good help. I'd like to see that motor working on a bike.
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