Understanding the mechanics of different electric bikes

sunil

Pedelecer
Aug 25, 2016
26
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bournemouth
hi All,

I am a new user to this useful community. I am looking to buy a new e-bike and have looked at multiple choices
1)front hub motor ..Not interested in them as manouevrability with heavy front wheel could be difficult
2)rear hub motor..quite interested in them. One of the reasonable bikes i am thinking is Carrera cross fire
3)crank drive motors..Liked them most but finding quite expensive. Some of the models which i liked are Giant and Raleigh ..basically which has yamaha or Bosche motors.
4)crank drive motor(with throttle). i only came across them today and finding them surprisingly cheaper than crank drive motors. example woosh bali or volt pulse

I am struggling to understand how the 'crank drive motor(with throttle)' works without pedalling them i.e just on throttle because as per my understanding the pedal wheel should keep on moving to get the power from battery.
Can someone please explain that. Let me know if i have not made my question clear enough.

Regards
Sunil
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
hi All,


I am struggling to understand how the 'crank drive motor(with throttle)' works without pedalling them i.e just on throttle because as per my understanding the pedal wheel should keep on moving to get the power from battery.
Can someone please explain that. Let me know if i have not made my question clear enough.

Regards
Sunil
Some crank drives incorporate a freewheel in the mechanism, allowing the chain wheel to turn while the pedals remain stationary.
 
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Benjahmin

Esteemed Pedelecer
Nov 10, 2014
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There is normally either a rotation sensor, on the crank or chain wheel, or a torque sensor somewhere in the drive chain. These sense the peddles being rotated and give instruction to the motor to drive. If there is a throttle, then, generally, this overides the sensor and gives drive when operated.
I think that's what you were asking.
There is some complication with different systems interpreting a rather wooly law in different ways. However if you give specific models then there's bound to be someone who knows that one specifically.
Myself, I have a front hub conversion and it's true that, when the drive kicks in suddenly, there can be some 'interesting' moments, especially on loose surfaces. But, Hey! It's an e-bike:D
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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The Bafang or any other after market type have an internally wired pas sensor but in a addition have the option of the throttle, throttle will over ride the pas usually. WIth the pas there is a freewheel element when the throttle is engaged so that if you have tired legs they can remain stationery.
This is borne out with my bbs01 lift the rear wheel off the ground rest the crank/ pedal against your leg and engage throttle wheel and chain rotates without pedal movement also same applies to the GSM.
 
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