Winter problem with Tongsheng TSDZ2

[bjorns]

This is the first winter since I converted my wifes Scott Sub 45 to an eBike. She has commuted to work during autumn and everything has worked well with the bike. The bike started to act up when the temperatures went below freezing so we moved the bike to a shed that we keep at 10 degrees Centigrade. It worked for a while but now there are other issues.

This is how my wife describes the problem:
"The engine makes a stressed sound, like it was overworked or strained, and stops working. If I stop pedalling, which is a reflex response to this sound, the engine goes quiet and I can carefully start pedalling again. The engine will work until something happens; it's almost always when changing gear to adjust to increased speed, but sometimes it happens when I start pedalling again after a pause down a small slope or whatever.
Lately it has become worse, to the point where the engine doesn't work at all when putting normal pressure to the pedals. If I turn the engine off completely, it works better but the pedals will keep 'hacking', as if I changed gear and there was a glitch and the new gear didn't take, If you know the feeling.
To sum up, I can't ride my bike at all and I need to fix this. Is there anyone of you who might have an idea of what could be the problem? I'm open for any suggestions!
In case it's relevant I have been using the bike in quite cold weather. "

Do you recognize this type of problem? What more can we do to find the cause of the problem?

/Björn

 

[endlessolli]

This sounds to me as if your sprag clutch is worn out. That part is replacable; either together with the the „big gear“ (easier, but more expensive) or you buy it separatey; this is cheapee, but you need a press to fit it into place. Search Tsdz2 and sprag clutch and you‘ll find more details

 

[fletchro]

If it feels like a bad gear shift while pedaling (I remember it felt like someone was hammering my bicycle frame from underneath the bottom bracket), it is probably the blue gear that is failing. If it feels like your pedals are slipping and not really supplying torque to the chain, then it's the sprag clutch. Source: I have experienced both of these situations on my bike.

 

[bjorns]

OK, I opened it up today. I got the blue gear out, but not the "pin" that the blue gear "sits" on. Does the blue gear look OK?

How do I force the "pin" that the blue gear "sits" on out? Do I need to open up from "chain side" as well?

 

[ilu]

Yes you need to open the drive side cover and you will see a small gear, which has the shaft that the blue gear sits on. Then you remove the circlip that is holding the shaft in place and you can push or gently tap the shaft to remove the snall gear. Then you should check that when you put the blue gear back on the shaft, that it turns freely and smoothly to one direction, but doesn't turn to other (in relation to the small gear at the end of the shaft), as there is a one way roller bearing inside the blue gear. The blue gear itself looks fine

 

[calab]

Not very robust the TSDZ2

 

[bjorns]

OK, so now I have removed stuff from the chain side. I tried to push out the pin and gear that holds the blue gear. I knocked on ith with a wrench, but it will not budge. Any ideas? Now that I look at the photos I might see a "lock ring" on the motor side. Do I need to remove it, or does it only keep the bearing on the "pin"?

 

[ilu]

Yes you need to remove the lockring as it holds the "pin" in it's place. After removing the small gear, test how the blue gear spins on the shaft. And also test how the big gear spins if you turn it by hand (easiest is to put back two of the screws that hold the chainring spider) and how it turns when you rotate the axle with a crank. This is to see if there is a problem in the main sprag clutch (which is similar to a freewheel): the gear should be able to move without the axle rotating and the axle turning should rotate the big gear clockwise, but not counter-clockwise.

 

[bjorns]

Well, we had a spare blue gear that I replaced the old one with in case that clutch was broke. Now when all is reassembled the bike sounds much more during normal operation. What could the reasons be for that? Wrong type of grease?