I fitted a Cyclotricity mid-drive kit last year: the motor is actually a Tongsheng. It worked very well for the first 250 miles but then started squeaking during pedalling. It ended up with loud prolonged squeals after only a mile, usually in low gear or changing gear. After checking the tightness of everything I could, without success, I noticed that a screw holding the two parts of the casing just inside the chainwheel was hanging out. Tightening it and the other three serving the same function seems to have cured the problem.
If you search for Squeaking Tongsheng mid-drive motor online you'll find several videos, and advice, but none that I saw mentioned this cause for the problem. Another one to consider . . .
Squealing Tongsheng mid-drive
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francovendee
- Posts: 3414
- Joined: 5 May 2009, 6:32am
Re: Squealing Tongsheng mid-drive
Glad you found the cause of the noise. I fitted one of these to an old Raleigh bike , the conversion was straightforward and I have been generally very pleased with it. Powerful enough, good battery range and very responsive when you need more power but----- My god it's not quiet. I've had the thing apart and tried several fixes suggested on the Facebook group, all without success. I think it is related to how much load is on the motor, light loads it's the loudest but working hard it isn't too bad.
I've come to think that it's a cheap motor and not anything wrong with it, just noisy.
I've come to think that it's a cheap motor and not anything wrong with it, just noisy.
Re: Squealing Tongsheng mid-drive
Have mine on a Tandem. 14,000 miles so far in 4 years. Only issue I've had was with the battery which required a BMS reset after the first month of use. Very pleased with it.
Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X2, Raleigh 20 stowaway X2, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840, Giant Bowery, Apollo transition. 
Re: Squealing Tongsheng mid-drive
We've three tsdz2 conversions in our household plus a spare motor acquired from a friend who 'upgraded' to a Bosch system (pah!).
Whilst they are not entirely maintenance free, the only significant issue I've had was needing a new motor controller PCB which was straight forward to change albeit time consuming.
The motor given to me had not been cared for and had been partly submerged and then not dried out leading to a rusty bearing or two. That motor had always been a bit noisier than my three anyway so a complete strip down and bearing changes later and all was back to normal but still marginally noise compared to the others.
From members on the pedelec forum it does seem that some motors are noisier than others - lucky of the draw then!
The motor on my main ride has done maybe 8-10,000 miles and apart from the controller is fine (and no problems with blue gear wear on any of them but we're all gentle assist riders using mainly assist level 1/2).
I did a writeup on the strip down on the Endless Sphere forum with bearings numbers - https://endless-sphere.com/sphere/threa ... wn.120206/
As for battery reliability, after two BMS fails on commercial packs, I now build my own. Yes, I've had a BMS problem there too but no difficulty in effecting a cheap repair, unlike proprietary systems (eg Mahle!).
Whilst they are not entirely maintenance free, the only significant issue I've had was needing a new motor controller PCB which was straight forward to change albeit time consuming.
The motor given to me had not been cared for and had been partly submerged and then not dried out leading to a rusty bearing or two. That motor had always been a bit noisier than my three anyway so a complete strip down and bearing changes later and all was back to normal but still marginally noise compared to the others.
From members on the pedelec forum it does seem that some motors are noisier than others - lucky of the draw then!
The motor on my main ride has done maybe 8-10,000 miles and apart from the controller is fine (and no problems with blue gear wear on any of them but we're all gentle assist riders using mainly assist level 1/2).
I did a writeup on the strip down on the Endless Sphere forum with bearings numbers - https://endless-sphere.com/sphere/threa ... wn.120206/
As for battery reliability, after two BMS fails on commercial packs, I now build my own. Yes, I've had a BMS problem there too but no difficulty in effecting a cheap repair, unlike proprietary systems (eg Mahle!).
Without my stoker, every trip would only be half a journey