Originally Posted by peace
I don't know much about electric bicycles any specific things to look for or recommended brands.
Voltage, Amp Hours (Ah), and a C-factor which is kind of like a multiplier to the Ah figure, and drive type.
Is it "safe" to get a used one off cragslist (probably not one answer to that).
Sure if it's from an experienced builder, I advertise on my local craigs as a Retailer not Private seller, search your local CL with 'electric' as the key word in Bicycles and check the Dealer box.
Also Does the watt output matter? I believe that 750 w is the legal limit yet a 300 w and a 700 w both max out at 20 mph ( i think for legal reasons) does the wattage translate to how much weight the motor can hold/pull or acceleration or something like that? thanks.
As mentioned above it all matters.
Personally I am no fan of hub motors or batteries under 36V.
Though a good engine can move you around pretty good direct drive (single speed) kind of like a 3 speed Pinto stuck in 2nd gear, and build a lot of direct drive and shifting gas bikes, I only do shifters for electrics.
This build for a mom and her teenage daughter that are both barley 5' tall just went out last Friday so I haven't even had time to post it here yet.
That is just a 24" 3-speed Macargi Rover bike but the system works fine on a 26" 3-speed bike.
The Rover was ~$230 delivered.
The 36V electric motor kit was ~$400 delivered from SickBikeParts.com
The 36V Battery had pretty wimpy stats at 12Ah but came with a mounting rack that would mount direct to a mountain bikes front downtube via the water bottle mount holes, comes out via a keylock, and came with a charger delivered for ~$370.
The system would work just dandy on a used 10-speed type bike for under $800 and trust me, gears make all the difference in the world.
It's a cool system, and as green and quite as you get on a motor assisted bicycle which would really impress your green friends.
All that aside they really are a pleasure to ride and even that bike would hit 30MPH in 3rd gear, they have the least amount of maintenance, and you can park it your kitchen with no ill effects.