BionX rear wheel experience

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sverker
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BionX rear wheel experience

I have not used this equipment and so would like your feedback on the below question.
With system turned off does the motor/wheel rotate just as freely as a normal wheel. I.e. Test by lifting upp the rear wheel and turn it how long does it rotate compared to the front wheel.

I would hope one does not feel any difference.

thanks in advance

reikiman
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Re: BionX rear wheel experience

Is this true even for a normal bike that doesn't have any motor on it?

I just went into my garage and checked the bikes there. I don't have one with a BionX kit but I do have a bike with a hub motor.

On a normal (no motor) bike the rear wheel makes more sound than the front wheel, there's this clicking sound that I suspect comes from the freewheel. The hub is more complex on the rear than the front. So the rear is gonna naturally have slightly different behavior than the front.

On my hub motor bike the hub motor adds weight to the wheel making it require more inertia to rotate the wheel.

sverker
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Re: BionX rear wheel experience

Ok let me ask in this way then does it have added friction ( i.e. the permanent magnets interact with the el motor rotor) that will cause added effort when biking on a flat surface at constant speed.

sandorszabo
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Re: BionX rear wheel experience

The rear wheel with the Bionx motor does NOT turn as freely as a wheel without the motor. The permanent magnets significantly slow the wheel down, even with the system turned off.

andys
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Re: BionX rear wheel experience

The BMC rear hub kit I got from EV tech spins as freely as the original non motorised hub. It was a big selling point for me on that hub.

http://www.texaselectricbikes.com/catalog/brushless-geared-motor-p-163.html

proton
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Re: BionX rear wheel experience

Right...
To test this, simply hold the BMC motor wheel ( but only from texas e.. b.. )in your fingers and blow gently on the tire.
It will amazingly start to spin !

The LiFepo4 BattMan www.falconev.com

strawhistle
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Re: BionX rear wheel experience

:?

Ok there are perment magnets on the rotor , and copper coils with IRON back iron ( makes Horse Shue madnets) +-+-+-+- in a closed circle ! On the "stater , to answer the questoin ? the magnets work aginst the poles and back iron , that causes the wheel to move as a "cog" !! Some hub motors have "one way clutch" !!! If the wheel is turned " Generator" a "load " will be generated 3PH , and a Potential will load the wheel . SO the answer i think is no Pluse you have "mass x Inertia" to over come !! LATER

thank GOD I wake up above ground !!!!

strawhistle
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Re: BionX rear wheel experience

after one way cluch (insert ) "NO DRAG free wheeling" Please ?

thank GOD I wake up above ground !!!!

davew
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Re: BionX rear wheel experience

There is a little bit of friction in the rear wheel, but not enough to feel while you are riding. The effort it takes to peddle a 60 lb bicycle will be much more noticeable especially on hills

What's the point of your question? An ebike is supposed to help you. Are you going to be riding around a lot with the power off?

"we must be the change we wish to see in the world"

Dennis
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Re: BionX rear wheel experience

Gearless hub motors add drag when the system is off and does not freewheel like geared hub motors. But when you spin it at a speed it is designed for, the EMF seems to make it easier to pedal even when the motor is off, but it's harder to keep it at that speed with no power input compared to a non motorized bicycle due to the added weight of the kit. It's a good trade off because I hate pedaling up hills at 8 or less mph.

I especially noticed the drag down steep hills, where non motorized road bikes could coast down at 45 plus mph. With the high torque 350W motor, the speed it likes coasting down the same hills with no pedal or power input is about 25 to 28 mph. With the low torque 500W motor, it's about 33 to 35 mph. If you exceed the optimal speed the motor is designed for by pedaling, you will begin to feel the resistance of the EMF. I've tested this out today with a planetary geared Schlumpf high speed drive which increases the front gear range by 2.5 times at high gear. I was able to add full pedal power going down those same steep hills without pedaling like a de-evolved monkey. With the 500W motor, I was only able to get it up to about 42 mph with alot of pedal effort.

20" wheeled Dahon Mu SL with PL500HS Bionx Kit and Schlumpf high speed drive.

sandorszabo
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Re: BionX rear wheel experience

The perceived effect of motor drag will, of course, vary with the diameter of the wheel.

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