Possible build Dahon Expresso and Tongsheng TSDZ2B

TJS109

Pedelecer
Sep 29, 2017
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Hi,
Thinking of adding a Tongsheng TSDZ2B mid drive kit to my Dahon Expresso. Wondering if anyone has any experience of doing this. I am a little worried about the weight I am adding.

One additional thing about torque sensing controllers. When going up hills and changing down gear to make things easier this presumably reduces the amount of assistance which is sort of counter intuitive. Are cadence sensors better in this respect in that they should increase the assistance as you peddle faster

Thanks in advance for any help and tips
 

Woosh

Trade Member
May 19, 2012
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Southend on Sea
wooshbikes.co.uk
One additional thing about torque sensing controllers. When going up hills and changing down gear to make things easier this presumably reduces the amount of assistance which is sort of counter intuitive.
I agree and this will become obvious when your legs are tired.
 
D

Deleted member 4366

Guest
Hi,
Thinking of adding a Tongsheng TSDZ2B mid drive kit to my Dahon Expresso. Wondering if anyone has any experience of doing this. I am a little worried about the weight I am adding.

One additional thing about torque sensing controllers. When going up hills and changing down gear to make things easier this presumably reduces the amount of assistance which is sort of counter intuitive. Are cadence sensors better in this respect in that they should increase the assistance as you peddle faster

Thanks in advance for any help and tips
Cadence sensor systems are better for everything except serious off-road stuff because you can adjust the power to what you want and when you want. The best cadence systems are the "torque simulation" (current control) ones from KT.
 

1boris

Esteemed Pedelecer
Sep 10, 2013
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One additional thing about torque sensing controllers. When going up hills and changing down gear to make things easier this presumably reduces the amount of assistance which is sort of counter intuitive. Are cadence sensors better in this respect in that they should increase the assistance as you peddle faster

Thanks in advance for any help and tips[/QUOTE]

Here is where the Bosch CX shines it doesnt loose torque at high rpm
 
D

Deleted member 4366

Guest
Are cadence sensors better in this respect in that they should increase the assistance as you peddle faster
That's last thing you want - trust me. It sounds sort of logical but it's absolutely diabolical, especially with a higher powered system. You want the opposite, so that the torque increases as your pedalling slows down
 

DouglasXK

Pedelecer
Oct 9, 2016
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Oxford
You’ll add 3.5kgs + the battery pack. For the 36v or 48v motor the total might be 6-7 kgs. You’ll lose the front derailleur. Check that the bottom bracket is “standard”.

I rarely change down a gear to go up a hill; these days i increase the assistance. Level 3 with the TSDZ2 works well and you’re almost a passenger. I’ve never used level 4.

A common opinion of many is the phenomenal range. I put this down to a) the relatively light weight and b) because the friction is low, you can ride it just like a normal bike and not a moped.

These motors are inexpensive; you get what you pay for.
 
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TJS109

Pedelecer
Sep 29, 2017
112
48
76
Glos
Cadence sensor systems are better for everything except serious off-road stuff because you can adjust the power to what you want and when you want. The best cadence systems are the "torque simulation" (current control) ones from KT.
Cadence sensor systems are better for everything except serious off-road stuff because you can adjust the power to what you want and when you want. The best cadence systems are the "torque simulation" (current control) ones from KT.
Thanks for that I now realise that most cadence sensors function as a simple on/off switch and switch on the selected power. these sensors seem to profile it slightly
 

Woosh

Trade Member
May 19, 2012
19,477
16,424
Southend on Sea
wooshbikes.co.uk
Thanks for that I now realise that most cadence sensors function as a simple on/off switch and switch on the selected power. these sensors seem to profile it slightly
Cadence sensors are usually also programmed to be sensitive to the RPM.
I ride both types and honestly, the difference is not much while you ride on flat roads, other than torque systems keep you fitter. The difference shows up mainly on the hills, torque systems are way more demanding. You need to select the right gear and right assist ratio to keep your cadence high and to suit your fitness.
 
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TJS109

Pedelecer
Sep 29, 2017
112
48
76
Glos
You’ll add 3.5kgs + the battery pack. For the 36v or 48v motor the total might be 6-7 kgs. You’ll lose the front derailleur. Check that the bottom bracket is “standard”.

I rarely change down a gear to go up a hill; these days i increase the assistance. Level 3 with the TSDZ2 works well and you’re almost a passenger. I’ve never used level 4.

A common opinion of many is the phenomenal range. I put this down to a) the relatively light weight and b) because the friction is low, you can ride it just like a normal bike and not a moped.

These motors are inexpensive; you get what you pay for.
Thanks all that seems very positive. I am struggling to find a supplier of these kits other than Amazon. The bottom bracket does not have a cassette fitted but is a standard 68mm wide not sure about the internal diameter though
 

Nealh

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Aug 7, 2014
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Well spotted £234 including shipping makes it a bargain.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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PSWPower have a Dutch/German warehouse as that's where they send their no EU tax stuff from, if you are lucky and it is sent from the EU there will be nowt extra to pay.
 

DouglasXK

Pedelecer
Oct 9, 2016
90
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Oxford
One additional thing about torque sensing controllers. When going up hills and changing down gear to make things easier this presumably reduces the amount of assistance which is sort of counter intuitive. Are cadence sensors better in this respect in that they should increase the assistance as you peddle faster
I’m eating my words here but whilst travelling along Killhorse Lane near Ludlow the gradient was such that I was able to experiment. If you’re going fast enough the power reduces which encourages you to go up a gear. Whereas going down a gear will increase assistance if near to stalling. TDSZ2 have flung a speed component into the algorithm.

The hills here are ridiculous here so what I’m describing is a bit extreme. 1st gear (a 7 gear granny freewheel) and assistance level 3 and 125kg and 48v 750w was barely possible. Nevertheless the motor performed well.

My friend on her Motus had to be pushed up.
 
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TJS109

Pedelecer
Sep 29, 2017
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76
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Thanks to everyone for their advice.
I have ordered the TSDZ2 from PSW and am awaiting delivery. I have decided to convert a Dawes Hybrid instead of the folder as I got concerned about the weight it being difficult enough to get it in and out of the car as it is. I mostly use the folder on canal tow-paths etc where there are no hills so decided the motor would be wasted.
 

DouglasXK

Pedelecer
Oct 9, 2016
90
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Oxford
A 48v 750w motor with all the bits, throttle etc, will cost to buy £250-260. When “tax is paid” you’ll separately pay the shipper when it lands in the U.K. £35+-£5 for handling charges; otherwise you’ll pay vat on the declared value of £110 + £10 for handling which comes to about the same as the “tax is paid” cost!

A battery is not included. I build my own.