Better view of the battery packBasket as seen from the front
OwnerEd Resnick
Owner's Other EVCrystalyte e-bike (original)
LocationSan Diego, California United States map
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Vehicle2007 Trek 820
All-steel frame with front suspension fork, 26" wheels.
MotorCrystalyte 5303 (aka Phoenix Racer) Brushless DC
DrivetrainRear hub motor
ControllerCrystalyte 36-72V 35A
Modified with 150V FETs and improved electric insulation around them to allow for reliable performance at 72V or more (I'll eventually upgrade to 96V).
Batteries6, 12.00 Volt, Lead-Acid, AGM
Two UB12-12, two EB12-12, and two EVP12-12. Don't ask. Basically they're each 12V 12Ah batteries, with minor differences in lifetime or range.
System Voltage72 Volts
ChargerSoneil 4808 and 2408
Top Speed42 MPH (67 KPH)
I can reach 42 mph on flat ground with no wind. That's with no pedaling since the gearing is too low on this bike; pedaling is totally useless above 24 mph.
AccelerationNot yet measured, but it's acceptable, if a bit slow.
Range11 Miles (17 Kilometers)
I went for one 10.6 mile trip once with hard riding and little pedaling, and at the end I was only getting 2/3 of normal power and undoubtedly the controller would have shut down power completely very soon, so 11 miles of hard riding is what I'd say.
EV Miles
Current:200 Miles (321 Kilometers)
Seating Capacity1 adult
Curb Weight120 Pounds (54 Kilograms)
Estimated. Bike is 34 lbs, batteries are 54, hub motor/wheel is about 30, and there are a few pounds of miscellaneous parts and components.
Tires26x2.0 Schwalbe Marathon Supremes.
Conversion TimeInitially just a few days; I bought a new motor and a new bike but migrated everything else over from my other e-bike (the red front-wheel-drive one). But the motor had a defect and I had to wait for it to get repaired, which took about a week (for shipping mostly). Then I've made ongoing nonessential enhancements like disc brakes and other bicycle upgrades, rewiring the batteries, etc.
Conversion Cost$3000 so far
Additional FeaturesThe bike can be easily stored inside my Camry without the use of any tools. I put quite a bit of thought into the batteries to keep them portable. I ended up using copious amounts of velcro; I undo a few velcro straps (the red ones), unplug the battery pack from the controller, and then the battery pack can be easily lifted by the makeshift handles (which are also done with velcro) and put away somewhere, like in my car trunk. Then I pop the kickstand down, remove the quick-release front wheel, store it in the car somewhere, and then the bike can be easily lifted and fit on top of the rear passenger bench.

I don't use a car rack because that leaves the bike vulnerable to tailgaters (which sometimes rear-end me), rain, high-speed air resistance that theatens to make it come loose when I'm going 90 mph, or theft if I park it somewhere.

code by jerry