OwnerAndy Schank
Owner's Other EVs2007 Xtreme X 1200
2006 Lashout Electric Scooter
Electric Trek 950 Singletrack
LocationRichmond, California US map
Vehicle2001 KHS Westwood folding mountain bike
I rode this as a non motorized folding bike for 5 years. Hadn't been riding it much lately, mostly because it is kind of heavy. I decided to make a powerful small EV out of it with ability to climb hills and go off road
Motor BMC Brushless DC
This is a new high end entry in the bike hub market from EV Tech in Texas. Light weight, powerful, very quiet and efficient, with loads of torque. No drag freewheeling.
DrivetrainBMC 900 watt brushless hub with planetary gears
ControllerCrystalyte 48V 20 amp brushless
I wanted to run the bike at 48 volts up from the 36 volt kit to raise the top end speed, since the bike runs small 20 inch wheels. This controller did the trick and matched up with the throttle wires as a direct plug in. The connection of the phase wires to the hub had to be figured out though, as the controller had a different plug than the original 36 volt kit one.
Batteries1 Ping Battery LIFEPO4 48V 15AH, 48.00 Volt, Lithium-Polymer
Nice compact 15 pound powerful 48 volt 15 AH Lithium Iron phosphate battery has the similar usable output of 4 12 Volt 22AH LA batteries that would weigh 60 pounds or more. Offers 30 amp continuous output. Makes me want to try a slighlty more powerful controller at some point.
System Voltage48 Volts
Charger Came with battery and is dedicated to the LIFEPO4
nice fast 3 amp smart charger at 58.7 volts
Instrumentationelectronic speedometer odometer
Top Speed22 MPH (35 KPH)
My goal was to have the ebike do over 20 MPH no assist on level ground, and it exceeded this. Can pedal past this speed on level ground or slight declines. Will do 14 MPH with no assist on 10% grade.Update: I have now ridden it on a hilly 10 mile route and averaged nearly 20MPH. On my 19 pound rode bike, I have a hard time doing 12MPH on that same route.
AccelerationGets up to 20 MPH pretty quick. With me pedaling, I can keep up with my son on a 1100 watt powered Razor dirt bike.

Did a test from zero to 100 feet, no pedal assist. took less than 7 seconds at a speed of 16MPH.
Range35 Miles (56 Kilometers)
Runs at full power for most of the range because of the linear response of the Lithium battery pack. . We have almost no level roads, so it may go 40 miles or further if not for the abundance of long and steep hills. One ride I did was over 20 miles, and it was still at 52.7 volts at the end of the ride.
Watt Hours/Milevery efficient motor. I can go 1 mile on about 1/3 ah of juice.
EV Miles
Start:486 Miles (781 Kilometers)
Current:705 Miles (1,134 Kilometers)
Total:219 Miles (352 Kilometers)
 
    As of 7/1/2008
Curb Weight60 Pounds (27 Kilograms)
Bike is steel frame and was about 32 pounds by itself. battery in the case with rack is about 16. Rear wheel with Hub motor is a tad over 10 pounds. About 1/2 the weight of many of the hub motors.
TiresMaxxis Max daddy 20 X 2.25
Conversion Time6 hours
Conversion Cost$1250 including Lithium battery pack. Bike itself was about $400 on a closeout.
Additional FeaturesMy 7 speed rear freewheel has an 11 tooth small sprocket and you need it if you want to pedal past the motor on level ground. Now try finding one that goes down to 11 tooth, as Shimano discontinued them and offers a 14 tooth minimum only.

I replaced the front 44 tooth crank ring with a 50. I can still pedal at a decent RPM at 25 MPH in the tallest gear.
This thing is really fun to ride. I have a couple of fast compact electric scooters, and the fact that you can pedal along with the throttle makes riding the bike much more engaging, plus I get a workout trying to out peddle the motor to go as fast as possible. The balance is good and not too tail heavy because of the light battery pack and motor. It rides like a normal bike. It is easy to transport because it still folds up. People are amazed at the power when they try it out for the first time. A cyclist friend exclaimed "you have got to be kidding" when he gave it full throttle.

code by jerry