Most electric bicycles, e-Bikes, are powered by hub motors, either un-geared
or using planetary
gears. Even the geared hub motors do not use the bicycle gears, they merely
use internal gears
that allow the motor to run at a much higher speed, and thus reduce the size
and weight of the
motor while producing more torque than an un-geared hub motor.
But mid-drive motors drive the chain and sprocket directly, and so they can
use the full range of
gears provided by most bicycles. It appears to me that mid-drive motors are
much superior to hub
motors for e-bikes, but I would like to hear the opinions of others to see
if I am on the right
track. Here are what I consider to be the advantages of mid-drive motors:
(1) They use the full set of gears provided by the bicycle and so provide
the best torque and
hill climbing ability for a given size motor
(2) They free the wheels from any weight or drag caused by a hub motor
(3) They eliminate any extra work required to change tires or wheels
(4) They keep the center of mass in the middle of the bike
(5) They actually reduce the wear and tear on the main sprocket and chain
because the
force is uniform over the sprocket rotation as opposed to foot pressure that
peaks at
a few points
(6) The multiplication of the rider's strength is uniform as opposed to the
jerky forces
provided by torque sensors.
The only disadvantage that I see is lack of re-generative braking, which
exists in un-geared hub
motors.
I came across what looks to me to be an almost perfect e-bike at an
affordable price at:
http://www.hightekbikes.com/index.html
a 350 watt mid-drive motor (the motor drives the chain-wheel so that all the
bike gears are
utilized giving it awesome hill climbing ability and the wheels are totally
free of any extra
weight or equipment) on an e-bike that weighs only 46 lbs and costs only
$1600 + sales tax. If
anyone has an opinion on such a bike I would like to hear it.
Thanks,
--
Larry Gales
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or using planetary
gears. Even the geared hub motors do not use the bicycle gears, they merely
use internal gears
that allow the motor to run at a much higher speed, and thus reduce the size
and weight of the
motor while producing more torque than an un-geared hub motor.
But mid-drive motors drive the chain and sprocket directly, and so they can
use the full range of
gears provided by most bicycles. It appears to me that mid-drive motors are
much superior to hub
motors for e-bikes, but I would like to hear the opinions of others to see
if I am on the right
track. Here are what I consider to be the advantages of mid-drive motors:
(1) They use the full set of gears provided by the bicycle and so provide
the best torque and
hill climbing ability for a given size motor
(2) They free the wheels from any weight or drag caused by a hub motor
(3) They eliminate any extra work required to change tires or wheels
(4) They keep the center of mass in the middle of the bike
(5) They actually reduce the wear and tear on the main sprocket and chain
because the
force is uniform over the sprocket rotation as opposed to foot pressure that
peaks at
a few points
(6) The multiplication of the rider's strength is uniform as opposed to the
jerky forces
provided by torque sensors.
The only disadvantage that I see is lack of re-generative braking, which
exists in un-geared hub
motors.
I came across what looks to me to be an almost perfect e-bike at an
affordable price at:
http://www.hightekbikes.com/index.html
a 350 watt mid-drive motor (the motor drives the chain-wheel so that all the
bike gears are
utilized giving it awesome hill climbing ability and the wheels are totally
free of any extra
weight or equipment) on an e-bike that weighs only 46 lbs and costs only
$1600 + sales tax. If
anyone has an opinion on such a bike I would like to hear it.
Thanks,
--
Larry Gales
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| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev