Hi. I have just fitted a Tongsheng TSDZ2 to my MTB. I'm familiar with e bikes with a hub motor, as I've owned one for 5 years, and have also converted another bike to a hub motor using a kit.

I bought the Tongsheng TSDZ2 after reading many reviews, and because I rode a mid drive Yamaha while on holiday and loved the torque sensing. I have paired it with a 36v 10aH battery.

The unit I got is supposed to be 350w, but I gather both the 250w and 350w motors are identical.

Anyway, after riding two different hub motor bikes over several years, I find the Tongsheng to be very underpowered in comparison. I have a long steep hill on my commute, and on either of my hub powered bikes I used to sail up with no problem. My first attempt at the same hill with the Tongsheng had me in first gear, full turbo and I barely got up the hill. The battery was fully charged. I ought to point out that I cycle a lot and also have a road bike, so I'm not that unfit!!

Any ideas, or am I expecting too much from the little motor?

Will using the open source software make much of a difference?

Is my battery powerful enough at 36v 10aH? It's only a couple of months old.

And does anyone know if there's any difference between the 250w and 350w versions?

It could be case of settings or it might be a case of pedalling too fast.

I think my settings are correct, but maybe you could tell me what they should be. Should the amp setting be on 16 for example? and what about the torque setting?

I'm interested in your final option. So, if I'm going up a steep hill, I shouldn't drop to my lowest gear and be pedalling like a maniac to get the most out of the motor? I should try and stay in a higher gear?

The power decreases as the RPM go up. Maximum torque is given at low RPM. I'm not too sure what is the optimum RPM for hill climbing. I would guess about 60 RPM. At 100 rpm, you get no useful help from the motor.

 

You have to search the forum for all the threads about optimum settings.

Surely for most of the range power goes up as RPM goes up, but torque goes down. At the top of the RPM range they both go down.

eg https://www.ebikes.ca/tools/simulator.html but I don't think they have the TSDZ2 explicitly.

The tsdz require the rider to pedal quite hard to provide full assist ,no free rides with this system[ unlike a bafang and ghost pedal] , if in the wrong gear or to little effort the assist is minimal .

It requires an adjustment in rider style and trail and error, it takes some time to get used to it try one gear lower than you expect and yes you have to pedal [its more of a workout]

The tsdz require the rider to pedal quite hard to provide full assist ,no free rides with this system[ unlike a bafang and ghost pedal] , if in the wrong gear or to little effort the assist is minimal .

It requires an adjustment in rider style and trail and error, it takes some time to get used to it try one gear lower than you expect and yes you have to pedal [its more of a workout]

Totally agree i took my new kit out for it,s first proper outing yesterday i love it because i still wanted a workout and get sweaty but also take a bit of pressure off my knees when going up hill which it does, it does take getting use to

The lack of power come from the torque sensor. Perhaps you can improve that by putting your feet off the pedals when you light the engine on (it does a torque sensor initialisation)

If it's still weak, you need to do a sensor calibration

 

https://github.com/OpenSource-EBike-firmware/TSDZ2_wiki/wiki/How-to-calibrate-the-torque-sensor

 

When it will be OK, if you break nothing (I don't start this job yet but I have to), you will have to choose a reasonable speed not to overheat this little engine (500 g) ; nothing to do with an hub engine (my old Q100 is better except in >15 %)

The tsdz require the rider to pedal quite hard to provide full assist ,no free rides with this system[ unlike a bafang and ghost pedal] , if in the wrong gear or to little effort the assist is minimal .

It requires an adjustment in rider style and trail and error, it takes some time to get used to it try one gear lower than you expect and yes you have to pedal [its more of a workout]

 

Agreed, sometimes it struggles on the same hill and occasionally it climbs quite fast in the same gear. In general it likes steep and short hills or shallow and long ones, but not medium and long ones. Lately it seems to be getting gradually weaker with average use of 12 times per year for two years now.

Know one has asked yet, so how fast are you riding up said hill?

Try a gear change before you hit the bottom of the hill and keep the pedals spinning

Slower top speed and on a larger rear gear, its harder if you have to change gear to get the motor back to its happy spot [pedal cadance]

On a 1km long 6% grade hill on 42t in the front and 32t or 34t in rear it's only 11-13km/h with a current fluctuating between 10-15A@36V, which is maxed out. In a 28t gear the motor starts growling and struggling. On a 15% 30m I was able to climb at 16km/h in a 28t gear, now I'm able to climb it only in a 32t gear despite strength training on a stationery exercise bike.

How fast are the pedals turning cadence and is it the 36v model or 48v, the torque difference is large between the two versions thats why woosh only sell the 48v to his spec. After my own back to back test in the same bike the 36 v was ok on the flat but could not sustain a high load of even feeble Essex hill, the hair drier even sounds different the is a mismatch between torque load and current drawn and once it gets hot the power output dropped

Surely for most of the range power goes up as RPM goes up, but torque goes down. At the top of the RPM range they both go down.

eg https://www.ebikes.ca/tools/simulator.html but I don't think they have the TSDZ2 explicitly.

I have a 750W which I've now been told is likely a 500W 48V. I would say that the maximum power is at about 50revs/ min and max efficiency at about 60 revs. So quite slow. The best efficiency of an internal combustion engine is near where the most torque is. The electrical motor has very different characteristics