wanted: TongXin motor part - outer ring

Hi folks,

 

I am trying to help an old lady with her made-in-china eBike.

The bike has a TongXin motor and the outer ring is brooken.

It is clear to me this is a weak point on this motor.

 

Question:

- anyone has / or know, an outer ring for this motor

- if I can't get the ring, what is closest fitting exchange motor as far as specs, dimensions and control signal

 

Hope someone can give some helping advice here.

 

Kind regards,

Ed

Forum member Jerrysimon might be the person to ask about these Tongxin and similar small motors. Cytronex still use them but I doubt whether they supply spare parts to non-customers.

 

Tom

Repair here on u tube but no mention of where he got the ring from, you could get a sleeve machined to press onto the broken ring as a support but it depends on cost.

 

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&sqi=2&ved=0CGAQtwIwCQ&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DymQyvh0L6iE&ei=KJzzU-juK-_T7AaNx4DIBg&usg=AFQjCNERrwEY5uy_aH27zRIvM8pcEJf3eA

This should be the same diameter for the spokes, you may need to swap the controller depending upon which controller is running the Tongxin, changing the controller will allow a significant increase in power as well (they are cheap), check the diameter with their diagram, they cme in 24 or 36 volts and there is a higher powered H version.

I looked at replacing one of my Tongxin's with the same motor but never got around to it.

http://www.bmsbattery.com/rear-driving/353-250w350w-q-85100sx-motor-e-bike-kit.html

Direct replacement motor:

 

http://outrider.en.alibaba.com/product/1249407064-211997191/Front_36V_80mm_halless_small_dc_brushless_motor_for_folding_electric_bicycle_kit_OR01A4.html

 

It looks like you have the old bolt on side cover - the latest ones have a screw on cover so you would have to rebuild the motor into the wheel.

 

If you can source an old one you can simply swap over the innards with the replacement without having to rebuild the wheel.

 

If you go for a new one you will have to match the voltage, rpm speed, number of spoke holes and have a matching cable outlet i.e. waterproof connect or flying lead.

Edited August 20, 201411 yr by shemozzle999

As replied earlier its probably better to just get a new motor from Outrider. There is a huge thread on here somewhere where I documented fixing these with photos from another poster.

 

Ps I am about to put a new Tongxin and Keyde motor up in the for sale section though they are 28H and configured for smaller 16" wheels at 260RPM.

 

Jerry

The Tongxin motor was made in about 6 variants so as always to give the same road speed & hill climb ability regardless of wheel size. If Tongxin's recommendation was followed this would have meant a road speed of 12 mph (20kph) & so quite good torque. Eg if it is a 26'' wheel then 160 rpm. To nowadays recreate this with the other commonly available mini motors is not so easy ( I have built a Q100 into a 24'' rear rim, & have a Tongxin 175rpm in a 26'' front wheel on the same bike, as a test. Thus the speeds are similar at 14.6 mph but the torque of the Q100 is better) I could not find a modern motor to give me 175 rpm in a 26' wheel (There is a small Bafang sw motor made as 180 rpm but it is not commonly stocked by the dealers). The Q100 is stated @ 201 rpm but is actually 249 rpm unloaded, the 201rpm being @ 5A - ie average rider up to speed on the flat. At the time the max ebike speed in China was 12mph now it is 15, hence the different accent on speed.

To sum up as Jerry says the correct variant motor from OutRider is most likely to give what the lady is used to in terms of both speed & climb ability

THANK YOU ALL for the given information and advices.

 

I have found an outer ring that I am going to pick up later today.

Hopefully it has the same size and fits perfectly.

 

I believe at this point that is the best option for me. The bike is used by an older woman with a handicap and more speed or torque is not wanted. Therefore the low speed - low torque Tongxin might be still the better choice.

I hope for her that this ring will last for some time.

THANK YOU ALL for the given information and advices.

 

I have found an outer ring that I am going to pick up later today.

Hopefully it has the same size and fits perfectly.

 

I believe at this point that is the best option for me. The bike is used by an older woman with a handicap and more speed or torque is not wanted. Therefore the low speed - low torque Tongxin might be still the better choice.

I hope for her that this ring will last for some time.

 

Glad you have managed to source one. I hope you will let us know how you get on with fitting it and if possible a link to the source.

Glad you have managed to source one. I hope you will let us know how you get on with fitting it and if possible a link to the source.

 

Sure, got it from ebike-kit.nl

 

Fitting, so far, is a disaster if you don't have the special tool.

They told me it works on a Bench Vise. I tried that but wasn't succesfull.

The trick here is that you need to push on 3 point all over the ring. With the Vise you push on 2 points from whih one is always close to the bearing wheel.

 

Will make a tool during the weekend.

Thanks for the link asterduc, you might be able to deform it the way you want if you can get access to large 3 jaw chuck on a lathe.

Tried it with the Bench Vise and some tooling, but that didn't work well.

Tried a hydraulic Press too, that that was scarry. So I didn't finish it.

 

The only remainig option was a ring with 3 pushers like the one showed on the video.

Doing so, all pieces came nicely together in a fraction of a second.

It worked and I was happy as a kid.

Placed the 36 bearings, grease and all the screws and rings.

 

Wheel back in place, all functioning properly.

Happy ending.

 

The old lady can use the bike again. I hope the ring will last for some time.

 

Thanks all for guidance.

Well done on getting the ring fitted :-) I like the fitting tool :-)

the

Well done on getting the ring fitted I like the fitting tool

 

this ring is a part that I had cut off from a 12V motor starter.

I drilled 3 holes and put M10 thread in it.

This did a perfect job.

M8 might have done it as well.

Thanks for posting your solution I am sure it will help others in the future.