SteveMush
10 mW
Recently finished installing a Kollmorgen HiKol 440W CCW motor in my converted 10-spd road bike.
This is the counter-clockwise motor version that can be had cheap on line - I got mine for $49.00 new.
Installation consisted of:
Reverse the one way needle bearing clutch in the output sprocket of a Lashout 4.75:1 planetary gearbox & install on motor in an aluminum support structure bolted across the down-tubes & under the top horizontal bar of the bike frame. #25 chain drives a 72T sprocket from the 19T sprocket at the planetary gearbox output. (spring loaded idler keeps tension high) The 72T sprocket is on a 5/8 inch aluminum jackshaft with go-cart ball bearings, the other side of which holds a 16T ACS freewheel sprocket mounted on a threaded adaptor. The 16T ACS sprocket drives a bike chain to a 44T freewheeling sprocket at the bottom bracket. Original chainrings are bolted to the 44T freewheel sprocket. I can use 5 gears, either leg or motor driven, which is quite adequate. The motor and jackshaft drive unit is enclosed in a neat rectangular box, painted a textured black for "stealth", that sits between my knees and legs below the horizontal frame bar.
Four 12V, 12AH SLA batteries and a charger are in a fabric bag atop a carrier platform over the rear wheels. Batteries are wired to 4-peg connectors so that the motor sees 24V, 24AH, but when the motor plug in the battery bag is unplugged and the charger plug is substituted, the charger sees a 12V, 48AH battery array for charging with a 12V, 10A 'smart' charger (quite a bit cheaper than the 24V versions of same). Full charge after full use in 4 hours (I don't fully drain the batteries).
Overall reduction ratio from the motor to the bottom bracket pedals axle is 49.5:1. This motor's highest efficiency is at 3271 RPM, which figures to a liesurely equivalent pedal cadance rate of 66 RPM at the bottom bracket at that motor speed. The motor can go to 3500 RPM, so there is some reserve speed above that. With my 280 pound fat *ss on the bike, it will cruise at 16.5 MPH on level ground. I intend to replace the 16T ACS drive sprocket with a 17T one, which should get about 18 MPH at cruise on a level road. If it still has reserve power, I will go to an 18T sprocket and look to get closer to 19 MPH on level ground. By letting the motor wind out to its most efficient speed, the amps load is kept low and the motor has yet to heat up at all in use. Moderate hill climbing ability is quite good, as I can shift down as needed. On level ground, one need not shift at all - it can be left in cruising gear and "lugged" from a standing start quite well, so long as I start at minimal throttle. One must throttle back a bit before shifting gears to avoud 'thunking' the rear gear set.
This motor, geared this way, has remarkable driving power for only 400W, while providing a decent commuting speed - I used to average 14 MPH pedalling and now average 16 MPH 10 miles to work and arrive without being in 'ball of sweat' condition at all. I just completed a 20 mile ride with moderate hills and had considerable power left. I expect the range on strictly flat ground would exceed 30 miles.
The installation is neat and contained in an unobtrusive 'black box' in the frame, so the stealth aspect is quite good, except for the whine from the planetary gearbox when under electric drive. I do pedal past police cars, as ebikes are not yet legal in the state of NY, where I live.
I would definitely recommend the Kollmorgen 400W HiKol motor in a homebuilt with this gearing ratio scheme. If it can get my fat *ss to work and back nicely, it should do fine for the more average rider!
This is the counter-clockwise motor version that can be had cheap on line - I got mine for $49.00 new.
Installation consisted of:
Reverse the one way needle bearing clutch in the output sprocket of a Lashout 4.75:1 planetary gearbox & install on motor in an aluminum support structure bolted across the down-tubes & under the top horizontal bar of the bike frame. #25 chain drives a 72T sprocket from the 19T sprocket at the planetary gearbox output. (spring loaded idler keeps tension high) The 72T sprocket is on a 5/8 inch aluminum jackshaft with go-cart ball bearings, the other side of which holds a 16T ACS freewheel sprocket mounted on a threaded adaptor. The 16T ACS sprocket drives a bike chain to a 44T freewheeling sprocket at the bottom bracket. Original chainrings are bolted to the 44T freewheel sprocket. I can use 5 gears, either leg or motor driven, which is quite adequate. The motor and jackshaft drive unit is enclosed in a neat rectangular box, painted a textured black for "stealth", that sits between my knees and legs below the horizontal frame bar.
Four 12V, 12AH SLA batteries and a charger are in a fabric bag atop a carrier platform over the rear wheels. Batteries are wired to 4-peg connectors so that the motor sees 24V, 24AH, but when the motor plug in the battery bag is unplugged and the charger plug is substituted, the charger sees a 12V, 48AH battery array for charging with a 12V, 10A 'smart' charger (quite a bit cheaper than the 24V versions of same). Full charge after full use in 4 hours (I don't fully drain the batteries).
Overall reduction ratio from the motor to the bottom bracket pedals axle is 49.5:1. This motor's highest efficiency is at 3271 RPM, which figures to a liesurely equivalent pedal cadance rate of 66 RPM at the bottom bracket at that motor speed. The motor can go to 3500 RPM, so there is some reserve speed above that. With my 280 pound fat *ss on the bike, it will cruise at 16.5 MPH on level ground. I intend to replace the 16T ACS drive sprocket with a 17T one, which should get about 18 MPH at cruise on a level road. If it still has reserve power, I will go to an 18T sprocket and look to get closer to 19 MPH on level ground. By letting the motor wind out to its most efficient speed, the amps load is kept low and the motor has yet to heat up at all in use. Moderate hill climbing ability is quite good, as I can shift down as needed. On level ground, one need not shift at all - it can be left in cruising gear and "lugged" from a standing start quite well, so long as I start at minimal throttle. One must throttle back a bit before shifting gears to avoud 'thunking' the rear gear set.
This motor, geared this way, has remarkable driving power for only 400W, while providing a decent commuting speed - I used to average 14 MPH pedalling and now average 16 MPH 10 miles to work and arrive without being in 'ball of sweat' condition at all. I just completed a 20 mile ride with moderate hills and had considerable power left. I expect the range on strictly flat ground would exceed 30 miles.
The installation is neat and contained in an unobtrusive 'black box' in the frame, so the stealth aspect is quite good, except for the whine from the planetary gearbox when under electric drive. I do pedal past police cars, as ebikes are not yet legal in the state of NY, where I live.
I would definitely recommend the Kollmorgen 400W HiKol motor in a homebuilt with this gearing ratio scheme. If it can get my fat *ss to work and back nicely, it should do fine for the more average rider!