|Location||Phoenix, Arizona US map|
|Vehicle||2009 Custom Built |
Designed and built over a few months from at least three scrapped bicycles and quite a number of other components, it is the second successful e-bike I've made, and the first for which I've built the bike itself, too.
|Motor||Invacare None marked Permanent Magnet DC|
24VDC 3.6A (no load) unknown full power rating. 120RPM gearbox integrated.
UPDATE August 2009: Same motor, now being run on 36V, so gearbox running at 180RPM max output.
|Drivetrain||Pedal plus motor assist. Pedals on first BB drive left side single chain ring driving chain to large ring on left side of bike's second BB Motor is a power chair motor plus 120RPM gearbox. Gearbox drives 24 tooth sprocket, driving chain to granny ring on left side of bike's second BB. Both of these can drive (simultaneously or independently) that spindle which drives the rightside pair of chainrings, which are the front part of a standard 12-speed bike drivetrain driving the 24" rear wheel. It should be an 18-speed, but I don't currently have another 3-ring set I can use on the right side. |
UPDATE August 2009: 2-ring and 3-ring are swapped, so motor 24T now drives 52T ring of 2-ring (pedals on other one. Motor now on 36V, so is more like 180RPM @ gearbox output at max throttle. Similar speed range, but much quicker rev up to speed and much lower current draw, as motor is kept more in it's higher speed range.
Originally a (maybe 10A) Scoot'n'go controller, was fried when I got it. Replaced relay and several cooked resistors, rebuilt it with two NTY100N10 123A/100V externally-mounted MOSFETs using old salvaged JFETs to drive them, with externally-mounted large TO-style snubbing diode pack from a PC PSU. Small but long heatsink salvaged from dead car stereo amp with active cooling used to mount all external parts on.
UPDATE August 2009: Now using a 2QD PCB with rest of electronic components being recycled parts from various junked electronics. Four MOSFETs, half-bridge regen-capable. Not currently using regen from wheel, because of freewheel at rear wheel cassette. If I pedal faster than motor is running (or leave throttle at zero and pedal), motor is driven by pedals for regen, and successfully puts current back to batteries thru controller.
|Batteries||3 MU-1SLDG, 12.00 Volt, Lead-Acid, Gel|
Used U1 deep cycle power chair batteries, 31Ah @ 12V, about 23 pounds each. :-( MK-Powered MU-1SLDG
UPDATE August 2009: Now using 3x 12V 17Ah 15 pounds each, Sacred Sun UPS batteries. (They don't list this model on their site; the closest they list is a 12V 18Ah). They're well used but seem to be working normally. The third (bottom in pack) directly powers the 12V lighting system, eliminating the 12V 7Ah SLA (5pounds) I had been using up to now. Weight savings using these smaller batteries is negligible this way, but simplifies charging and wiring. Also makes it easier to place batteries on bike as they're physically half the size of the others, even though there's one more (it goes where the lighting battery used to, in the central triangle).
|System Voltage||36 Volts|
|Charger||Guest Pride 2904-24L|
power chair battery charger, 3A @ 24VDC. Takes overnight to fully charge the system from dead, only about 30 minutes max to recharge from my short work commute.
UPDATE August 2009: Since now it's a 36V system, this only charges 2/3 of the pack. I use a Sorenson 60V/1.5A current-limited adjustable voltage and current bench supply to charge the third battery, set at 14.4V 1.5A.
|Heater||None needed, this is Phoenix, AZ. ;-)|
That said, motor would make a good one; it's too hot to keep my hand on for long after a couple of miles.
Controller heatsink, though very small, is at most around 10F above ambient.
|Instrumentation||m100 PDA running Veloace. Analog needle-deflection style voltage and current meters.|
UPDATE August 2009: No longer have voltage and current meters since update to 36V; they were for 24V system, and current meter only went to 6A, not useful for measurements on this system. Used cheap DMMs for test results listed above, not permanently mounted on bike.
Want to use Cycle Analyst, can't yet afford one.
|Top Speed||22 MPH (35 KPH)|
22.3MPH on a flat straight canal path, with pedal and motor. Typical ride is 16-17MPH with pedal and motor. Can do about 15MPH on motor alone, but is hard on motor, time it would last is unknown.
UPDATE August 2009: At 36V with regeared drivetrain, it's max *tested* speed is 20.3MPH, but could probably go signifcantly faster than that for a moment or two if I put full pedaling power into it as well as full throttle in highest gear. 17-18MPH typical is possible with no pedalling, but would probably only have 8-10 miles range on that at best.
UPDATE August 2009: Still no numerical measurements, but now even under solely motor power, will accelerate from a complete stop to stable 8-9MPH in a couple of seconds. Previously this required pedaling as well.
|Range||22 Miles (35 Kilometers)|
Best range, totally drained with no recharging till returning home, with about 2 hours of rest time half way through, was 22 miles. Typical one-way range (recharge only at destination) about 15 miles.
UPDATE August 2009: Max range since 36V update not yet tested. Using some pedalling and medium speeds of 12-16MPH, have had at least 11 miles with at least 36V left (nominal 40V full charge). Expect I could probably get another 5-10 miles like that, so similar performance to the 24V setup, even though the 36V setup uses batteries with half the capacity.
|Watt Hours/Mile||30 Wh/Mile |
Haven't measured the full current draw, but it is at least 10A at load with pedaling at about 17MPH. Meter I have that reads higher won't take that much current for long enough to test it. Other meter pegs at 10.
UPDATE August 2009: Some better measurements for 24V operation with old drivetrain were well over 20A+ (guesstimating 50+) for acceleration from dead stop even with some pedal, and around 15A cruising at speed.
36V and new gearing is 6-10A typical cruising, and up to just over 25A (breaker pop level) at startup from stop with no pedaling. At higher speeds, 17MPH+, current draw goes up past 20A (max meter reading) to hold 20MPH speed with any headwinds. Under no winds, stays around 17-19A.
|Seating Capacity||1 adult, not including flatbed trailer (which might seat two small people, or one average).|
|Curb Weight||150 Pounds (68 Kilograms)|
At least 46 pounds is battery, plus another 5 or so for wiring, controller, and misc hardware only needed for the motor and batteries. The motor/gearbox is around 15 pounds. The rest of the bike isn't light either, at roughly 55 pounds. Was several pounds heavier before changing from the wooden seat to the tube/mesh version. (Have never weighed entire bike, just most components).
UPDATE August 2009: With the swapout of batteries being roughly equal in weight (51 pounds separate lighting + traction for 51 pounds traction/lighting combined), plus some cages to hold the new batteries (old ones were in my cargo pods, new ones are on bike frame) minus the old rear over-tire rack, weight is still roughly the same at a guesstimate. Have not measured it yet.
|Tires||24" knobby MTB tires, with Slime protection strips and regular tubes with Slime chunky automotive version installed. Would rather have smooth tires but don't have any available in my scrap bikes. 50PSI inflation.|
UPDATE August 2009: Front tire is still 24" MTB style, but is a gray wheelchair/powerchair tire; center is continuous so reduces rolling resistance a little on straights (turns still bumpy). Rear tire is now a 26" road-style tire, much reduced rolling resistance. Same 50PSI inflation and Slime protection/strips.
|Conversion Time||Probably a couple of hundred hours or so of time scattered over 3 months or more. Some of it is work from previous bike ideas, so really less than that. |
At least half of the time was spent evolving the frame design and chainline; the actual time to build it as it is now might only be 1/4 of the total, were I to start with what I know now.
UPDATE August 2009: Still in progress, changing as needed to suit new parts available or new ideas.
|Conversion Cost||$20 for welding wire, $8 for grinding discs. Everything else on it is recycled from something else, and cost nothing. Perhaps call it $20 for any parts I might have bought for other projects that got recycled into this one instead, that I just don't remember.|
|Additional Features||Full street-legal lighting system, including turn signals, brake lights, and running/marker lights. Runs on separate 12V7Ah SLA. Lights salvaged from Honda gas scooter carcass and from a prior bike I built LED lighting for, with CCFL headlights salvaged from computer scanner transparency/slide/negative adapters. |
Recumbent seat is nice and comfy. Like riding your lawn chair around. :-)
Lockable aluminum cargo pods, roomy enough for a complete grocery run for at least a couple of weeks' worth.
UPDATE August 2009: Lighting now runs on bottom 12V17Ah traction battery, removed unneeded 12V7Ah battery.
|At the May 1st 2009 Phirst Phriday Phoenix Phreaks ride, it was a big hit. |
Anyone looking to build their own is welcome to visit the blog at WebPage and comment their questions there on specific posts; I'll reply as needed with what info I have.
Since this and all other such projects are made from donated and found parts, any scrap bikes or other part donations are welcome, contact me via email link above.