Which pedal sensor to use

[Kuorider]

My A2b Kuo is very under geared and I intend to fit a larger chainwheel and longer cranks. The existing unit has the sensor stator and pickup as one sealed unit integral with the chainwheel. the stator part is located by two pins mounted on the BB. This arrangement appears to be a torque sensing device as the pedals turn a few degrees against strong springs before the rotating disk moves.

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The control box is this one, no maker's name,

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Three wires go from the unit to the controller,red ,blue, green. My question is can any one suggest a replacement sensor disk and pickup of the more common type to substitute here so that I can fit a standard chainwheel. Thanks all.

 

[trex]

the controller looks like a Lishui, it should work with a most pedelec sensors.
Please post a picture of the connector where it plugs into the controller

 

[Kuorider]

Hi,Trex, Thanks for your prompt reply. I have reassembled the controller into it's alloy box and it's a bit of a job to strip out being tucked in a fitting under the BB and really tight. The connector looks a fairly common black plastic three pin job, flat with the pins in line across, and a little retainer tab. I would have no problem changing this .I can strip it out tomorrow if necessary and post a pic. Can you suggest a source for parts ?

 

[trex]

PM Hatti @ Woosh - I think they charge a couple of £ for it.

 

[Kuorider]

I found a pic of the same one on ebay this can be zoomed to inspect the part.
http://www.ebay.co.uk/itm/Powercycle-Salisbury-CrankSet-with-Pedals-and-the-Original-Pedal-Sensor-/400733077518?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item5d4d8d800e

 

[Deleted member 4366]

That's interesting. I have a couple of the black plastic housings identical to yours, and they have an optical rotation sensor inside. I guess you can put anything in it.

The sensor goes with the controller. You'd need to know what output it gives - probably analogue 0 -5v like a throttle, so you might be able to replace it with a throttle. The normal pedal sensors are digital, so won't work with your controller; however, controllers aren't very expensive, so you can replace the whole lot. You should get a modern one with LCD, which will allow a throttle and normal PAS. You only need to keep the battery and motor connections. Chuck the rest.

 

[Kuorider]

Hi,Again, The bike has a throttle and an LCD . I may just drill out the rivets and see what's inside.

 

[Deleted member 4366]

The black plastic bit is in two halves that clip together.

 

[Kuorider]

Hi ,Again, Thanks for your input, I've learned a bit more now and had a word with tech help. This is a torque sensing chainwheel and thus makes the bike quite different from the cadence type, so my proposed change is a step sideways to a different type of pedalec. As Dave said ,the controller etc would have to be totally changed, easy enough but I feel a custom build coming on.

 

[pdarnett]

Let me know if you want to throw out the torque sensing chainwheel, I'd love to have a look and try it on the metro!

 

[Kuorider]

Will do, but my inclination now is to leave the bike as is, it is very much a 'top two gears' bike in use which is fine. Given that it's a 20" wheel folder the performance is suitable for it's size and type. Overall it is a good bike ,it looks and feels well made and runs nicely. I thought however that your Metro would have had a similar system being from A2B .

 

[pdarnett]

Nope, mines a ver1 metro, no pedal assist at all when I got it. I've fitted on since but just a rotation based one. I did put a 53T chainwheel on it though!