New "TSDZ2 Torque Sensor Central Motor"

[sysrq]

How do you ride? Do you use a throttle? If so, do you use it from standstill? Do you use brake sensors? Do you go up steep hills?

My guess is that this is more likely to happen if you use the throttle, especially from a slow start - and/or you don't have brake sensors and brake a lot under power. But I know some don't agree that brake sensors are necessary...

i use throttle mostly, also from standstill but . no i dont use brake sensors because i have hydraulic brakes and i dont care about buying these magnetic brake sensors. also yes i shift while on throttle i know this isnt good for the drivetrain but replacement parts are cheap on my bike(8 speed)

Imho it's using the throttle from standstill that's going to contribute a lot to this sort of wear I would think. Using the motor only to accelerate from a standing start puts much more torque through the motor gearing than if you start by pedalling and use the motor to assist your pedalling.

I also think that brake sensors are necessary - in a car when you brake to a stop you don't just expect the engine to just stop with you - you depress the clutch (or the automatic gearbox does it for you) to disengage the motor and stop it stalling. If you don't have brake sensors and you're pedalling whilst braking or the motor is simply running on a bit - you're putting pressure on the motor gearing as it's trying to push you forward as you hold it back with the brakes - that's going to cause more cog wear...

thanks....looks like i will buy the brake sensors now! and hope this time my motor will stay good

Doesn't most people instinctively stop peddalling when braking?

[Ianane]

26 rim 36 chainring 11 smallest cog - 40 kmh easy on flat and bike is great for mtb climbing

That should equal a cadence of 92 (down from 98 for a 28 rim).
I guess it really boils down to your main use case (steep mtb slopes vs. street commuting) and in which cadence range you are comfortable - and if you use osfm enabling field weakening to still get support @ high cadence numbers.

To get back to the topic I was refering to:
The core subject here was motor capacility and burnout.

42T, creates cause for concern of motor burnout.
That's assuming people drive like idiots and don't shift enough...

Yes yes, we all know we all know better. But my point is about the general design...
42T puts a lot of responsibility on the rider and we all know "the average joe" is not thát responsible

I think I'm the one of irresponsible ones since I tried to climb some short 6-9% hill at low cadence on 42t/18t combination during one of the first rides in 26° ambient temperature to see how powerful the motor is and it was stalling. After that there was no choice but use lowest gears (36t, 32t, 28t) and spin which translates to 8-12Amps on most of the hills. So there is no way to tell if the magnets got weaker after one time abuse since gluing an external temperature sensor on laminations instead of deeply in the windings as most motors do will show cumulative delayed temperature response only.

SysRQ... you're not alone with having high gearing available and it's all horses for courses. I live and commute from the top of a 500 to 600m climb over about 12kms... an average 4% but there's a few 13 to 25% climbs of 20 to 100 meters amoungst it all depending which way I go.
I have four different routes to and from work which vary greatly in busyness and how the climb works. I'm running a 52 ring and 11-34 9speed cassette. I used to run on the stock 42 ring going up and then lift the chain on to the 52 going down but I rarely used my lowest sprockets, with the 52 my cassette gets thrashed on every sprocket in its time.
I use the high gears for going down, in places gravity will drag me down at around 60kph on my preferred route, I just tuck in and rollllllllllll ( another route as 20%+ and I can exceed 80kph but the first time I tried some kangaroos jumped in front of me and scared the shit out of me... so not preferred).
So, I use the high gears with gravity and the low gears going up with the motor. I've upped the max speed for assistance to 35. I have no throttle attached or brake isolators (I found they turned my lights off when I used the brakes and as I often commute in the dark on winter mornings going down, losing light was unnerving).
I also pedal, nominally adding around 190watts of leg power at around 75 to 85 cadence, and get home in a dripping sweat even at near zero degrees.
I also ride in summer, so often 30 to 40 degrees and I'm just a sheet of sweat when I get home on these days... my family doesn't want to know me until I'm out of the shower.
On a few of these days tried getting a temperature reading from the casing with a household point -and-shoot thermometer, which read around 50 to 55 from memory - not really hot to touch -
I've clocked up well over 3000k so far and have been measuring my times (on this conversion and a range of other conversions and stock bikes) and they are pretty consistant given winds and variable motivation levels, so I don't seem to have de-magnetised anything yet but will be playing with the OSF and the cooling pads as soon as my warranty is up in a couple of months... and I have the time.
Thanks to everyone here for their contribrutions, I bought my 48 vTSDZ2 on the strength of all the info here and I cruise in and out as I wait for my twelve month probation to expire and I can play with the big kids.

[afzal]

Doesn't most people instinctively stop peddalling when braking?

But the motor doesn't stop at that time due to ramp down time. And if there is no ramp down time, riding will be jerky

[w0utje]

I converted my 2013 Trek 8.5 DS to e-bike last year with a Bafang mid-mount motor. Two months ago, I sold the Bafang and installed a TSDZ2 with 860C and OSF. Beautiful…. Recently, the motor developed a gear whine noise and I replaced the blue gear and greased. Gear whine still very present, so I bought a TSDZ2B on AliExpress and installed just the motor yesterday. I had to swap out the motor controls because of the open source firmware – no problem. Just did a test ride and dead quiet. The new “B” version has improved internal gears, bearings, and sprag clutch. This is too cool. Back in the saddle again...
-

First off:
TongSheng is known for shipping a clutch that is already barely capable of covering the load (110nm rated) if made by a good manufacturer, but ship it chinesium grade.

I've seen no evidence they started to use higher quality bearings in the TSDZ2B, nor have I seen evidence of better internal gears.

However, I do know that they moved from freely available clutches (and thus replaceable by a quality variant) to a self-designed clutch.

The company that has 0.2mm(!) tolerance on a bearing axle and isn't able to pick the right clutch, is now starting to design their own clutches... That's not a good sign.

High quality clutches are EXPENSIVE. A good quality clutch is about 1/3-1/5th of the complete price of the TSDZ2. No way they ship one of good quality now, it's simply not possible at their pricepoint.

I also call bullshit on the better internals, considering everything that is actually breaking due to design issues (circlips, tolerances etc) is still the same.

Maybe, but the B pedals a lot lighter above the speedlimit and it feels a lot more "tight" then my 2 older tsdz2's I already had. Feels the same, maybe even better then my first tsdz2 with the longer crank axel. What is the most reliable of the 2 tsdz2's I have. The 2nd tdsz2 I bought with the smaller axel has a lot more play in everything in the motor. And I mean a lot, the new tsdz2B feels better build. But time will tell

[ornias]

I also ride in summer, so often 30 to 40 degrees and I'm just a sheet of sweat when I get home on these days... my family doesn't want to know me until I'm out of the shower.
On a few of these days tried getting a temperature reading from the casing with a household point -and-shoot thermometer, which read around 50 to 55 from memory - not really hot to touch -
I've clocked up well over 3000k so far and have been measuring my times (on this conversion and a range of other conversions and stock bikes) and they are pretty consistant given winds and variable motivation levels, so I don't seem to have de-magnetised anything yet but will be playing with the OSF and the cooling pads as soon as my warranty is up in a couple of months... and I have the time.

"I don't seem to have de-magnetised anything "

50c on the casing, means you've most likely already overheated the motor or are just barely shy of doing so.

You've made the mistake of assuming that the casing temperature is the motor temperature. The actual problem with IS that the casing has barely any conductivity with the actuall motor unit. So it cannot be accurately measured the way you did it.

Unless you've an actuall temperature sensor installed on the actuall motor unit, the measurements are lawballing it by dozens in some cases.

[ornias]

Maybe, but the B pedals a lot lighter above the speedlimit and it feels a lot more "tight" then my 2 older tsdz2's I already had. Feels the same, maybe even better then my first tsdz2 with the longer crank axel. What is the most reliable of the 2 tsdz2's I have. The 2nd tdsz2 I bought with the smaller axel has a lot more play in everything in the motor. And I mean a lot, the new tsdz2B feels better build. But time will tell

The lighter above the speed limit is the new in-house designed clutch, which I can assure you is the same mediocre quality and non-replacable by a resputable brand as far as we're currently aware.

The smaller axle, is not TSDZ2B related, that upgrade has been made a few years ago already.

"Time will tell"
is not a good metric, at least not to magically proclaim it has improved internalls. No one, not even Tongsheng, proclaims it has better internals. You just got one of the tighter ones, which is nice, with the same design flaws they all have.

Please don't proclaim design improvements without evidence of them.
You're just confusing people.

[Ianane]

I also ride in summer, so often 30 to 40 degrees and I'm just a sheet of sweat when I get home on these days... my family doesn't want to know me until I'm out of the shower.
On a few of these days tried getting a temperature reading from the casing with a household point -and-shoot thermometer, which read around 50 to 55 from memory - not really hot to touch -
I've clocked up well over 3000k so far and have been measuring my times (on this conversion and a range of other conversions and stock bikes) and they are pretty consistant given winds and variable motivation levels, so I don't seem to have de-magnetised anything yet but will be playing with the OSF and the cooling pads as soon as my warranty is up in a couple of months... and I have the time.

"I don't seem to have de-magnetised anything "

50c on the casing, means you've most likely already overheated the motor or are just barely shy of doing so.

You've made the mistake of assuming that the casing temperature is the motor temperature. The actual problem with IS that the casing has barely any conductivity with the actuall motor unit. So it cannot be accurately measured the way you did it.

Unless you've an actuall temperature sensor installed on the actuall motor unit, the measurements are lawballing it by dozens in some cases.

At the moment I can only hope I haven't cooked the innards. As I mentioned, I don't want to 'crack the casing' until my warrantee period is up because I'll have no hope of getting any support from the dealer once I do. On the plus side, my times remain consistant within the variables I mentioned, so I live in hope.
Are there any tests that will diagnose a 'demagnetised motor'?

[NisseMan]

Had to open my TSDZ2, was almost dry, almost none grease at all.
Added some cooling and new grease, sound levels drops and casing get a bit warmer. Jacked up power to 600 W max.
Update, motor still pretty noisy when is cold, when heating up after few min its almost silent
Update 2; took some 500km, now the cranks start to wobble. Bearings seen real crap on this motor

[ornias]

I also ride in summer, so often 30 to 40 degrees and I'm just a sheet of sweat when I get home on these days... my family doesn't want to know me until I'm out of the shower.
On a few of these days tried getting a temperature reading from the casing with a household point -and-shoot thermometer, which read around 50 to 55 from memory - not really hot to touch -
I've clocked up well over 3000k so far and have been measuring my times (on this conversion and a range of other conversions and stock bikes) and they are pretty consistant given winds and variable motivation levels, so I don't seem to have de-magnetised anything yet but will be playing with the OSF and the cooling pads as soon as my warranty is up in a couple of months... and I have the time.

"I don't seem to have de-magnetised anything "

50c on the casing, means you've most likely already overheated the motor or are just barely shy of doing so.

You've made the mistake of assuming that the casing temperature is the motor temperature. The actual problem with IS that the casing has barely any conductivity with the actuall motor unit. So it cannot be accurately measured the way you did it.

Unless you've an actuall temperature sensor installed on the actuall motor unit, the measurements are lawballing it by dozens in some cases.

At the moment I can only hope I haven't cooked the innards. As I mentioned, I don't want to 'crack the casing' until my warrantee period is up because I'll have no hope of getting any support from the dealer once I do. On the plus side, my times remain consistant within the variables I mentioned, so I live in hope.
Are there any tests that will diagnose a 'demagnetised motor'?

"Are there any tests that will diagnose a 'demagnetised motor'?"
Sadly enough it's not a black-and-white thing, so it can be a "bit demagnetised". For those cases there really is not test to say definitively.

If it's "completely cooked" you will know...
It will look like and smell like a burned piece of meat.

[ornias]

Had to open my TSDZ2, was almost dry, almost none grease at all.
Added some cooling and new grease, sound levels drops and casing get a bit warmer. Jacked up power to 600 W max.
Update, motor still pretty noisy when is cold, when heating up after few min its almost silent
Update 2; took some 500km, now the cranks start to wobble. Bearings seen real crap on this motor

Tolerances and bearings are absolute jackshit on the TSDZ2.
There also an issue of the crank being only actually attached on one side.

Some (extra) enduro bearings do wonders.
And also consider a good clutchbearing, but those are hella expensive (like 100 bucks expensive)

In terms of tolerances:
Not much you can actually do. Currently waiting on my prototype axles from the CNC company to see if I can do a limited production run for that...

[Sturmey]

"Are there any tests that will diagnose a 'demagnetised motor'?"
Sadly enough it's not a black-and-white thing, so it can be a "bit demagnetised". For those cases there really is not test to say definitively.

Would it not be the case that an unrestricted demagnetised motor would run faster with no load (increase RPM) due to weakening of the field? I have noticed that an older high mileage hub I have appears to run about 10% faster with no load measured with speedo by lifting wheel off ground and full throttle (with fully charged battery) compared to similar test when new.
I wonder would similar test work with my standard TSDZ2 (with throttle)?

[pxl666]

demagnetized motor takes more current for less power output

[ornias]

Both correct ofcoarse, but for slightly/partly demagnitised motors there isn't some sort of reference you can check when making measurements

[Sturmey]

Both correct ofcoarse, but for slightly/partly demagnitised motors there isn't some sort of reference you can check when making measurements

I am going to suggest that there is a reference that only requires a clock or stopwatch (and a throttle/way to activate motor at full speed).
When the magnets loose strength, there is a reduction of the magnetic field and this has similar effect as field weakening. i.e.
1 Reduction of torque.
2 Reduction of efficiency.
3 Reduction of back emf that gives an increase of rpm at no/very low loads.
The first two effects can not be easily measured without lab equipment. However the last effect can easily be measured and compared to another similar motor or compared to itself if a measurement has been taken and noted when the motor is new.
So for example, in my case I have the 36V Tsdz2. I put a piece of white tape on chainwheel guard, put bike on stand, select low gear and push throttle fully. I record battery voltage (41 V ) and rpm (104) approx by simply counting the turns. I repeated the test again with battery close to nominal voltage(36V) and get approx 96 rpm. (only takes a few minutes).
This becomes my reference RPM against voltage.
It would appear to me that any damage to motor will probably change these values. In the case of demagnetizing, I would expect the same effect as field weakening i.e. A proportional increase of rpm if I repeat the test.
However, although this appears to work with some hub motors, I am not sure in practice how well this works in the case of the TSDZ2, e.g. Does the controller interfere with this (e.g If field weakening already turned on/implemented in controller)?
Anyhow, I put it out there as a suggestion. If it doesn't work with TSDZ2, let me know.

[ornias]

Both correct ofcoarse, but for slightly/partly demagnitised motors there isn't some sort of reference you can check when making measurements

3 Reduction of back emf that gives an increase of rpm at no/very low loads.
The first two effects can not be easily measured without lab equipment. However the last effect can easily be measured and compared to another similar motor or compared to itself if a measurement has been taken and noted when the motor is new.

We should document some of those defaults here/github
That was basically what I was refering about

[tosiwic227]

Had to open my TSDZ2, was almost dry, almost none grease at all.
Added some cooling and new grease, sound levels drops and casing get a bit warmer. Jacked up power to 600 W max.
Update, motor still pretty noisy when is cold, when heating up after few min its almost silent
Update 2; took some 500km, now the cranks start to wobble. Bearings seen real crap on this motor

Tolerances and bearings are absolute jackshit on the TSDZ2.
There also an issue of the crank being only actually attached on one side.

Some (extra) enduro bearings do wonders.
And also consider a good clutchbearing, but those are hella expensive (like 100 bucks expensive)

In terms of tolerances:
Not much you can actually do. Currently waiting on my prototype axles from the CNC company to see if I can do a limited production run for that...

Has anyone tried to replace all these stock Chinese bearings with better ones? Does that even make sense? Maybe this will lead to lower noise or more stable operation?

[NisseMan]

Any complete list of all the bearings?

[Elinx]

Any complete list of all the bearings?

For that there is the Tsdz2 Wiki
Here is the list

[Wapous]

To make it more visual!

[tosiwic227]

Any complete list of all the bearings?

[tosiwic227]

To make it more visual!

How to remove these bearings from the rotor?

I use expensive thermal paste between the stator and the flanges and I want to replace the bearings with better ones so that the engine will work for a long time without disassembly.

[NisseMan]

I got few 6902 bearings, any other that have high load?
The new bearing seems slightly to big, the shaft don't have correct diameter.
I think i will strip down the motor and fix it, plasma spay the shaft to fix the diameter.

[Elinx]

..... the shaft don't have correct diameter. ....

That is a well known problem
There is just one bearing on that shaft and on the other side an rubber seal, so the shaft (and maingear) can wobble.

By adding 2 (or 3) extra bearings that wobble will be minimized, because the shaft is on both sides supported.
Filling the space between shaft and inner bearing can improve this last bit too.

If you replace the rubber seals for bearings, these must be waterproof and sealed on the shaft.

NB
Because you have opened the complete motor, I advice before remounting to add an aluminium or copper heatsinkplate (about 1mm) for better heat dissipation. In the wiki this is described this with silicon heat conductive pads.

[tosiwic227]

..... the shaft don't have correct diameter. ....

That is a well known problem
There is just one bearing on that shaft and on the other side an rubber seal, so the shaft (and maingear) can wobble.

By adding 2 or 3 extra bearings that wobble will be minimized, because the shaft is on both sides supported.
Filling the space between shaft and inner bearing can improve this last bit too.

If you replace the rubber seals for bearings, these must be waterproof and sealed on the shaft.

NB
Because you have opened the complete motor, I advice before remounting to add an aluminium or copper heatsinkplate (about 1mm) for better heat dissipation. In the wiki this is described this with silicon heat conductive pads.

Poor tolerances of the pedal axle is it a manufacturing defect or maybe it was done by the manufacturer intentionally so that the torque sensor works correctly? if you borrow the foil under the bearing and eliminate the backlash, will the torque sensor work correctly?

[Elinx]

....
Poor tolerances of the pedal axle is it a manufacturing defect or maybe it was done by the manufacturer intentionally so that the torque sensor works correctly? ...

Who knows, but the shaft is just one time changed after all these years.
The last version is shorter and has just one bearing on the axle, the older one two.
So you can't call it an upgrade.
I can't imagine that this tolerance has to do with the torquesensor, but imho it is done for easy assembling of the motor.