Throttle detailFront side viewDrive closeup
OwnerSteve Boser
Owner's Other EVs2009 Tidalforce S-750
2006 Actionbent E-Jetstream
1980 Worksman Adaptable
2010 KMX Cobra Tadpole recumbent
2003 Giant Revive conversion
e bike v1.55
2010 KMX Cobra Recumbent Quad
LocationAloha, Oregon US map
Email email image
Vehicle2008 e bike v1.5
Originally two Motiv mountain bikes cut and spliced together with 10 inch extension. This is my third electric bike. the first two had 17 Ah batteries hanging off each side of the rear rack which made for poor handling. By stretching the bike 10 inches the batteries stack up under and behind the seat making handling much nicer. And the rear seat tube allows various options. So far I've been able to add a second seat and removable pegs so my youngest daughter can ride along, a large rear rack which is capable of holding 2 panniers on each side. Wondering if the engineers at Xtra-cycle got a few idea's from my design.
MotorBosch Permanent Magnet DC
DrivetrainEV Warrior dual friction drive motors using the original Curtis 1505 controller with a custom made 5K throttle
ControllerCurtis 1505
Batteries2, 12.00 Volt, Lead-Acid, Gel
These were originally used in a UPS, purchased used 5 years ago
System Voltage24 Volts
ChargerSchumacher 24 volt
lead acid auto charger originally designed for medical scooter use
HeaterN/A
InstrumentationSchwinn Cycle computer. Still need to add amp meter and volt meter
Top Speed20 MPH (32 KPH)
18 on flat ground
AccelerationAcceptable if you pedal on take off
Range10 Miles (16 Kilometers)
Range is variable, dependent on how much assist you provide. My goal is max range with only start off assist
Watt Hours/MileI haven't yet added instrumentation, however I have blown a 40 amp fuse in series with my battery pack so its probably in that ball park
EV Miles
Current:25 Miles (40 Kilometers)
Seating Capacityone adult one child
Curb Weight80 Pounds (36 Kilograms)
TiresI highly recommend the Specialized Nimbus tire for Ebike use. Even with friction drive which is used on this bike Nimbus tires are worth the cost.
Conversion TimeAbout 1 month
Conversion CostProbably $200, Bikes were purchased second hand. Tires $40 Batteries $5 each. Can't remember what I had paid for the controller and motor. $5 for gears for throttle assy
This was built more as a learning experience than anything else. As I mentioned earlier, previous eBike's I've built had large 17 amp/hr gel cells hanging off the side on the rear rack making handling unpredictable and heavy. I thought moving the location below the seat would make for a more normal ride. I was correct in my assumption as this bike handles every bit as well as it would have without the additional weight.
The throttle was another story as I had purchased several crappy commercial throttles, dissatisfied with what's available I made my own using gears from a RC car and a half hour of time on my lathe. I also put the throttle on the left side of the handle bars to reduce the crowding on the right side. Finally I've been enjoying this task as it seems to require a never ending variety of skill sets, and the good news my welds are still holding!

code by jerry