TSDZ2b mid drive update

[Tigertone]

Hi I have recently upgraded my Tongshend Mid mount emotor to include a thumb throttle and now I find that the peddle assist is not working. However, the thumb throttle is working fine. Has anyone any ideas as to what is causing this problem ?

 

[kevinmccune]

Hi I have recently upgraded my Tongshend Mid mount emotor to include a thumb throttle and now I find that the peddle assist is not working. However, the thumb throttle is working fine. Has anyone any ideas as to what is causing this problem ?

I cannot say for sure,I havean inkling its designed that way, my newest ride has( I assume) a TSD and doesnt have a throttle just a torque sensor( I prefer throttle and PAS) it may be that way to help protect the motor

 

[Tigertone]

Thanks

 

[harryS]

I believe that TSDZ2's that are throttle compatible have an 8 pin cable that supports a display with a plug for the throttle. Is that how you upgraded, simply plugging it into the display? Then it shouldn't affect pedal assist.
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The TSDZ2 units that do not have a throttle use a 6 pin cable to the display. I've never seen these models, both my units are 8 pin, but I would assume you have to go into the motor to find the extra wires and bring them out to attach the throttle.
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I've never opened my motors either, but I have read about people breaking the torque sensor wires when opening their motors, Do you think that happened?

 

[Gionnirocket]

I'm not totally familiar... But instead of opening the motor, wouldn't it be better to replace the harness from the motor to the display with the needed 8 pin version?
From what I understand the wires emerging from the motor that connects to the display harness is the same for all versions.

 

[PedalUma]

Hi I have recently upgraded my Tongshend Mid mount emotor to include a thumb throttle and now I find that the peddle assist is not working. However, the thumb throttle is working fine. Has anyone any ideas as to what is causing this problem ?

Did you modify the inside of the motor? For example replace the controller. The black protruding knob on the controller is the pickup for cadence. It needs to be properly seated. Also, the red and black wires need to be connected from the torque sensor to the motherboard. Is it under warranty? Did you get the motor from a reputable supplier, they are not all the same. This is a highly unusual problem.

 

[Tigertone]

I believe that TSDZ2's that are throttle compatible have an 8 pin cable that supports a display with a plug for the throttle. Is that how you upgraded, simply plugging it into the display? Then it shouldn't affect pedal assist.
.
The TSDZ2 units that do not have a throttle use a 6 pin cable to the display. I've never seen these models, both my units are 8 pin, but I would assume you have to go into the motor to find the extra wires and bring them out to attach the throttle.
.
I've never opened my motors either, but I have read about people breaking the torque sensor wires when opening their motors, Do you think that happened?

Thanks for your interesting reply.
This is what I did
Replaced TSDZ2 for TSDZ2b
Replaced display
Fitted new brake levers with motor cutout
Fitted new thumb throttle
This is the outcome
On throttle only the bike can easily reach 15 mph/25kmph
However, the motor doean't kick in when I peddle.

 

[PedalUma]

I'm not totally familiar... But instead of opening the motor, wouldn't it be better to replace the harness from the motor to the display with the needed 8 pin version?
From what I understand the wires emerging from the motor that connects to the display harness is the same for all versions.

Normally the wires from the controller are either six pin or eight pin, although there are harnesses that will plug into an eight pin so you can use a six pin display.

 

[PedalUma]

However, the motor doean't kick in when I peddle.

There is a problem with either the torque sensor and or cadence sensor. You should inquire about sending the motor back. It could not pass QC like this. It is defective. And not your fault.

 

[EMGX]

Hi I have recently upgraded my Tongshend Mid mount emotor to include a thumb throttle and now I find that the peddle assist is not working. However, the thumb throttle is working fine. Has anyone any ideas as to what is causing this problem ?

Was the only reason you switched to a "B" version was to gain a throttle? You could have just switched out the controller from a 6 to a 8 pin version to gain the option for a throttle. It sounds like you might have a defective controller or torque sensor.
FWIW I don't see any real advantage of the B version other than the new main gear which includes two one way clutches may be more robust than the older version that has one sprag clutch in the gear while the other clutch bearing is integrated into the blue plastic gear which may be more prone to failure. I bought a spare blue plastic gear for <$10 as a spare but have never had to use it. Replacement would be simple - I know this because I've had one motor disassembled to make it coaster brake compatible. The plastic gear in that motor showed no wear after over 1000 miles of riding in mountainous terrain and no failure of the integrated one way clutch bearing.

 

[Gionnirocket]

Normally the wires from the controller are either six pin or eight pin, although there are harnesses that will plug into an eight pin so you can use a six pin display.

As you may remember I looked in doing a TSDZ2B build a little while back and I thought the motors were all equipped to handle 8pin and you would choose the proper pinned harness to match your desired handlebar accoutrement.
Never mind....

 

[harryS]

No assist at all in Turbo mode? I've read that the TSDZ2B's are tuned for less power (to save the motor).

 

[PedalUma]

I love the B. Plenty of power and oh so smooth. The new clutch design allows it to ride without resistance without the battery. I made one that had a throttle and was all through frame. That meant translating the 8-pin controller to the differently colored wires of the 6-pin display and separately running the wires to the throttle and translating their colors. This is how that throttle bike turned out. Going without zip ties is like skinny dipping.

 

[EMGX]

It doesn't seem like there would be much difference. Both the older version and the newer B version each have two clutches. As far as I can tell the B version has both clutch bearings contained in the main gear. The older version has one sprag clutch in the main gear that allows the motor to turn without turning the cranks and another one way bearing pressed into the blue reduction gear that allows for the cranks to be rotated without spinning the motor. Both bearings in the old version are very smooth and offer minimal resistance (almost no resistance in the blue plastic gear which allows the cranks to turn without spinning the motor).
FWIW I seem to recall that the instruction manual mentioned that the throttle doesn't allow for full power, instead it is limited vs non-throttle assist.
In addition there are some potential downsides of the B version including cost of main gear replacement if that became necessary. Also lack of aftermarket dished chainring choices which wouldn't be an issue if the stock 42t chainring is adequate for ones uses. I have a 34t chainring on one motor which provided better gearing for hills, it is also narrow/wide which the stock chainrings don't provide.

 

[PedalUma]

The B is also better protected from water incursion on the drive side. It has a different step-down gear system. Throttles and speed sensors add lag. I ditch them. Ahh, so much better. The idea of a throttle has more appeal than what it does in the real world. The B does not take standard chainrings because of that added water protection. They will scrape a seal or need to be filed by 2mm around the inner diameter.

 

[Tigertone]

Normally the wires from the controller are either six pin or eight pin, although there are harnesses that will plug into an eight pin so you can use a six pin display.

Thanks to everyone for their in-depth helpful comments.
Just so everyone knows exactly what I've been doing.
I installed the TSDZ2 a while back but I wanted to try it with a throttle so I ordered a TSDZ2b 8 pin controller to swap out. However when you do this you have to change a whole load of other things. And, as it turned out swapping the controllers out is not an easy job and in hindsight I would not do the same again, this is because getting the old one out and installing the new one is hard work due to silicon sealer all over the place and only a small hole to get all the cables through. However, the new TSDZ2b is quite pricey " £225 pounds "
So, there we have, so far a less than perfect conversion. The throttle works great, with speeds easily reaching 15mpj but sadly no peddle assist. I have stripped the motor down and checked the controller and all looks good. I have also made sure that the cadence sensor is correctly aligned but still the motor refuses to spring into life on peddle assist. Finally I have contacted the supplier of the 2b informing them of my problem and I await their reply.

 

[PedalUma]

It can be difficult to seat the controller with the required precision for the cadence sensor pickup. It must go all the way into its hole and the #2 Philips screws need to be locked down from the drive side. I use a string to make sure a wire is not crimped under it. Also the red and black wires from the torque sensor should be locked into the white two-pin connector with a mini-zip tie. All the best.

 

[Tigertone]

It can be difficult to seat the controller with the required precision for the cadence sensor pickup. It must go all the way into its hole and the #2 Philips screws need to be locked down from the drive side. I use a string to make sure a wire is not crimped under it. Also the red and black wires from the torque sensor should be locked into the white two-pin connector with a mini-zip tie. All the best.

Thanks for your helpful comments

 

[EMGX]

I'd be confident that the glitch in your new tsdz2b is fixable. When the problem is resolved consider posting your overall impression of B vs your other one. I have two of the non-B versions, a 36v 500W and 48v 750W, both work great IMO. Smooth, natural torque sensing and provide very good assist (48v 750W more powerful, of course) but I'm not using either. The 48v isn't installed and I don't have plans for it, took it off favoring a much lighter weight without and stock bike's 3x chainring. The 36v is on a beach bike that I haven't ridden in over a year. I assume you have a European legal 250W motor. Ebike that I do ride occasionally is a nice (but still 40+lb.) Yamaha PW-SE powered gravel bike. Still, I think the Tongsheng is an excellent performing, durable, simple to install and easy to service option for a relatively inexpensive conversion.

 

[harryS]

OK, so it wasn't a new motor. Try the hidden settings to read the torque sensor which may tell you if the controller sees it. They are so hidden that I never was able to access them on my TSDZ2, but I've read that they exist.