Is there a Tongxin expert in the house?

Pedalo

Esteemed Pedelecer
Sep 10, 2009
443
1
I have a broken Tongxin motor as reported near the end of this thread:

http://www.pedelecs.co.uk/forum/electric-bicycles/7300-electric-brompton-stopped-working.html?

Basically the problem is that the motor makes a noise and you can hear something spinning inside but the wheel doesn't turn.

Jerry kindly lent me his special tool he made up for taking a Tongxin apart. Having got the motor apart I can see the cause of the problem:



As can be seen the outer ring around the planetary rollers looks to have cracked - which presumably means the rollers are no longer able to turn it and just slip.

If I can get hold of another motor (perhaps broken in some other way), does anyone know how easy it would be to replace this? I think getting the old ring off might be O.K. but since it's necessarily a tight fit I suspect it would be hard to get a new one on?
 

jerrysimon

Esteemed Pedelecer
Aug 27, 2009
3,292
112
Cambridge, UK
As I guessed a cracked freewheel ring. It seems a common problem and has been reported by a few users. I have no idea why it happens or how to prevent/delay such a failure :(

At least you have a couple of motors and can swap parts between the two if need be to extend the life of one hub motor.

On second thoughts just checked your pic again its the main ring not the ring that comes off :confused:

These are my pics





And the link where I took the motor apart.

Regards

Jerry
 
Last edited:

mj8765

Finding my (electric) wheels
May 8, 2009
22
0
Motor ring

Hi

We have some replacement rings - but it is a "bit of a bugger" fitting them and requires a special tool (which we have) or we can sell you a new motor to swap the inners into your wheel.

Feel free to give me a call.

Martin Jackson
Home page
0845 094 2735
 

HarryB

Esteemed Pedelecer
Jan 22, 2007
1,317
3
London
What you have found is a known weakness and happened to me. Cytronex have the tools and expertise to fix the motor - try giving them a ring.
 

jerrysimon

Esteemed Pedelecer
Aug 27, 2009
3,292
112
Cambridge, UK
Hi

We have some replacement rings - but it is a "bit of a bugger" fitting them and requires a special tool (which we have) or we can sell you a new motor to swap the inners into your wheel.

Feel free to give me a call.

Martin Jackson
Home page
0845 094 2735
Martin great to see you supporting us Tongxin owners :D

Regards

Jerry
 

Pedalo

Esteemed Pedelecer
Sep 10, 2009
443
1
Hi

We have some replacement rings - but it is a "bit of a bugger" fitting them and requires a special tool (which we have) or we can sell you a new motor to swap the inners into your wheel.

Feel free to give me a call.

Martin Jackson
Home page
0845 094 2735
Thanks for replying Martin and for providing some options. It was good to talk to you.

As I mentioned on the phone, fortunately I do have another motor which has been keeping me on the road for now at least. I'm hoping my working motor will keep me going over the next few months, by which time there might be some other interesting options to consider ;-)

Thanks again.