Just fitted a TSDZ2 on my cargo bike, now gearing is wrong

[haddock]

Hi guys
I am all new to this electric bike stuff.
I have a Nihola cargo bike, which I have fitted a Tongsheng TSDZ2 mid drive motor on.
My gearing before the Tongsheng TSDZ2 was 33/19, with SRAM S7 internal gears.

The TSDZ2 has a 42t chainring, and now my highest gear feels like the lowest.
Where can I buy a chainring around 33t in europe which will fit the TSDZ2?

Thanks!

 

[Gavin]

Hi guys
I am all new to this electric bike stuff.
I have a Nihola cargo bike, which I have fitted a Tongsheng TSDZ2 mid drive motor on.
My gearing before the Tongsheng TSDZ2 was 33/19, with SRAM S7 internal gears.

The TSDZ2 has a 42t chainring, and now my highest gear feels like the lowest.
Where can I buy a chainring around 33t in europe which will fit the TSDZ2?

Thanks! View attachment 36603

Interesting bike

34/42/52T Electric Bicycle Bike Chain Ring Wheel for Tongsheng TSDZ2 Motor | eBay

Find many great new & used options and get the best deals for 34/42/52T Electric Bicycle Bike Chain Ring Wheel for Tongsheng TSDZ2 Motor at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

 

[haddock]

Interesting bike

34/42/52T Electric Bicycle Bike Chain Ring Wheel for Tongsheng TSDZ2 Motor | eBay

Find many great new & used options and get the best deals for 34/42/52T Electric Bicycle Bike Chain Ring Wheel for Tongsheng TSDZ2 Motor at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

Thanks. Cargo bikes is very popular in Denmark for commuting in Copenhagen.
I have actually already ordered a chainring from this seller on ebay. But they ship from China, so the estimated delivery is 31th july - 4th september.

 

[Gavin]

Thanks. Cargo bikes is very popular in Denmark for commuting in Copenhagen.
I have actually already ordered a chainring from this seller on ebay. But they ship from China, so the estimated delivery is 31th july - 4th september.

You could use an adapter and then just buy a chainring locally. These guys have a German warehouse though a lot of stock also comes from China:

130 BCD or 104BCD Chainring Spider Adaptor Gearing For TONGSHENG TSDZ2 TSDZ3 - PSWPOWER.com

www.pswpower.com

We see a few "Bakfiets" style cargo bikes and a few longtails here in the UK, but not many of those. Too many angry car drivers and narrow roads....

 

[vfr400]

The TSDZ2 has a 42t chainring, and now my highest gear feels like the lowest.

That doesn't make sense. Did you say it the wrong way round. Your chainwheel is bigger than before, so will raise the gearing, not lower it.

 

[peter.c]

Another way is change the rear cog on the sram 7, to a larger one more teeth =slower or less teeth faster
cheaper option and more options to buy quickly

 

[haddock]

I know it sounds wrong, but there is no resistance when I pedal. It feels like I am driving in forstå gear. Or maybe it is how the TSDZ works?
I’m picking up the bike tomorrow from the garage, then I can post a video

 

[peter.c]

Once the assist kicks in in turbo mode, that is the feeling its like several people helping to pedal , but once the speed limit arrives assist stops
Try to pedal with zero assist switched on thats what will tell

 

[haddock]

I’ve picked up the bike today from the garage and cycled around 10km home. In 7th gear I am not able to drive above 18km/t. It seems like it is freewheeling when I try to pedal as much as possible.

in 3rd gear it seems like I am able to drive around 20km/t, but not more.
I have recorded a video:

is there something wrong with my motor maybe?

 

[Gavin]

It seems like it is freewheeling when I try to pedal as much as possible.

I don't really understand what you mean by this. Do you mean that once you get to 18km/h there's no resistance on the pedals (like the chain has fallen off)?

One thing you might not be aware of- IIRC the TSDZ has an upper cadence limit of (I think) 90 rpm. So if you pedal too fast you'll find the motor assistance stops.

Don't know if that explains any of the issues you're having....

 

[haddock]

I don't really understand what you mean by this. Do you mean that once you get to 18km/h there's no resistance on the pedals (like the chain has fallen off)?

One thing you might not be aware of- IIRC the TSDZ has an upper cadence limit of (I think) 90 rpm. So if you pedal too fast you'll find the motor assistance stops.

Don't know if that explains any of the issues you're having....

yes. It is not possible to pedal faster. I thought that when you’ve reached the limit the engine just stopped helping. But it is just like there is no gear when reaching 18 km/t.

maybe it’s possible to see here.

 

[vfr400]

What size chainwheel have you got now?

 

[haddock]

42 tooth in the front.

 

[Gavin]

Just checking terminology:

When you said 3rd gear and 7th gear, are you counting from the biggest gear?

So for example, 3rd gear has got more teeth on it than 7th?

 

[haddock]

It is internal gears in the hub. So 1st is lowest, then 2nd and so on.
If I reach around 20km/t there is no torque when pedaling.

 

[Gavin]

So based on post #9 you're saying it's faster in 3rd gear than in 7th? And yet 3rd gear is lower....

Did you try switching the assist off like @peter.c suggested in post #8?

 

[haddock]

So based on post #9 you're saying it's faster in 3rd gear than in 7th? And yet 3rd gear is lower....

Did you try switching the assist off like @peter.c suggested in post #8?

Yes. Because I am able to pedal faster in 3rd. The motor does not cut off as soon as in 7th.
I have tried without the engine on. Then it is hard as hell to pedal this heavy bike.

 

[peter.c]

The assist speed cut off is set to eu spec and or the wheel size is not set to the correct dia
Which wheel is the speed sensor on and what is the magnet gap
The final suggestion is list the max speed in each gear motor powered and if its lower ie slower or faster then do the same with the back wheel off the ground
have you got the throttle version

 

[haddock]

Today I had time to look at the bike again. I adjusted the speed sensor so the gap is 1,2 cm between sensor and magnet. In 5 speed the bike seems to work at its best. The gearing is to low though.
I suspect my 6th and 7th gear to be defective. When I pedal in 6th or 7th there is some “holes” (I do not know the English term).
the rear wheel is bought used (thanks a lot :/) , so I will have to try find another.

 

[haddock]

Well. Today I fitted the original deore 9-speed rear wheel. This only made a new problem. The chain alignment (is this the correct term?) is now way off. I am not able to shift into the lower gears without the chain is coming off at the front chainring.
Can this be sorted out? Or am I forced to change my rear wheel again?