Electric Bikes - Motorizing a folding bike, have motor, need bike

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rkdjones
12-14-11, 11:24 AM
There was an earlier thread on asking about motors to fit a particular bike. My question is finding a bike to fit a particular motor. I have a BMC V2-T hub motor on a 20" front wheel with a 36V battery pack. It is the perfect motor for my application - it has no drag, and climbs the hills I need to climb, and has a perfectly adequate top speed of about 15mph.

I want to find a bike with a decent gear range (a good 7 or 8 speed), that I can mount the motor, and swap out the crankset with my 115mm Isis crank (why a short crank is another story). I want to keep the price down. Weight is not a concern. A strong steel fork is required.

My first thought was getting a used kids bike and getting a long seat post and stem (not as easy as it sounds). This is still an option, but a folder is already set up for adults (I'm 5'9") and might have a longer wheelbase than a kids bike. So I am looking around for a folder that would work. Giant Expressway I, Downtube Nova, and Citizen Miami look good on paper.

I would like to hear what you think about my approach.

Robert

cerewa
12-24-11, 07:04 AM
don't get a kid's bike. A BMX bike that is made to be used by an adult might be fine (don't get a longer seatpost than the bike is made for because the bike may not be able to cope with the additional stress... more length equals more leverage on the connection between the seatpost and the frame).

A folding bike should be great though. The questions you need to ask (and don't buy until they get resolved) are whether the front fork is narrower than a standard bike (since a narrow fork won't fit your hub) and whether the fork is aluminum. (Aluminum and carbon fiber may be too soft to survive the turning force that an e-bike axle puts out).

If those issues are resolved, then any quality folding bike will do.
rkdjones
12-26-11, 07:53 PM
The more I look around, the more I am leaning toward a non-folding 20" mini velo. I don't need the attributes of a folder (and don't want to pay for them), and it looks like there are a few mini-velos that would be well suited. The only folder that still looks attractive is the Xootr Swift (or original Swift) if I can find a used one. Robert

GTALuigi
02-29-12, 04:06 PM
the best setup is what i had before Mu SL which is the lightest folding bike with a motor + battery kit of your choice
once you add on the e-bike kit the bike will gain a few pounds and it'll not be as easy to flip around any more, but still great for the subway rides