closeupbelt sidefull view
OwnerGregory Zaitoon
LocationChicago, Illinois United States map
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Vehicle2009 Trek 820
steel framed Trek 820, heavy but durable,added motor to it. Perfect match for such a heavy bike.
DrivetrainCurrie 36v 1000 watt motor running on 24v with initial 3 to 1 belt drive then a chain reduction, the belt drive makes it a very quiet ride. Has an end reduction of about 8 to 1 which I feel is perfect
about a 10 year old 36v controller that I had from previous projects.
Batteries8, 3.20 Volt, Lithium-Polymer
lifepo4 20AH bought them on ebay for about $28 per cell. Would not recommend that experience to anyone. I guess you get what you pay for. I think 3 or 4 of the cells only have about a 10-12 AH capacity. Also have a very quick internal discharge if storing.
System Voltage24 Volts
Don't ask. I'm actually using a lead acid charger but closely monitoring the voltages. Skipping the CV part of cycle altogether. Don't think it would really improve the performance of the cells anyways. Charge tham at about 8 amps until voltage of each reaches about 3.7. What's good about a 24 volt charger is when the cells reach about 3.7 volts the current draw will drop dramatically thus not destroying the cells
Instrumentationnone currently. use the wind as a gauge
Top Speed35 MPH (56 KPH)
Once you shift through about three gears , you don't want to go any faster.
AccelerationPretty good for 24v. Motor has awesome torque but smells funny after a hard ride. I hope it doesn't burn out.
Range10 Miles (16 Kilometers)
EV Miles
Current:60 Miles (96 Kilometers)
    As of 3/21/2010
Seating Capacityme and my parakeet
Curb Weight0
Not sure, but not too heavy, maybe 50 to 60 pounds
Conversion Timecouple of days at the end but much more than that machining the parts
Conversion Cost50 for motor
200 for battery
every thing else I already had on hand
This project is not the easiest to make. You need to fabricate the motor plate, mount and use a lathe extensively to machine adapters for the freewheels, not to mention the cranks also have a freewheel on them. I didn't want to purchase cyclone parts so I made them myself. The crank arm has a threaded piece on it to accept the freewheel. The crank sprockets are bored out to bolt onto the freewheel. The belt reduction shaft is 5/8 diameter with one bearing on each side. The large pulley is a Gates model. The one attached to the motor was made on a milling machine and was a serious pain to make right, because the motor only has a stub of a shaft when you receive it. But overall a very fun bike to ride, more fun than a hub motor because you can shift gears, and much less noisy than a geared reduction. I personally think I should use a proper charger and battery management, but for these cells, I don't think it's needed. If anyone has any questions feel free to email. Thanks

code by jerry