Torque sensor with hub motor?

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
Hi everyone,

I'm bulding an e-bike out of a Pinnacle Lithium, with a Bafang hub motor, kt controller etc.
I've previously tried out an e-bike with pas cadence sensor and found it a bit anoying when standing/hill starts.
I've heard that pas torque sensors give a more natural feel and presumably would improve the standing/hill start feeling(?)

So, can anyone advise if it's possible/sensible to use a pas torque sensor with a DIY hub motor bike?
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,563
3,056
Telford
Hi everyone,

I'm bulding an e-bike out of a Pinnacle Lithium, with a Bafang hub motor, kt controller etc.
I've previously tried out an e-bike with pas cadence sensor and found it a bit anoying when standing/hill starts.
I've heard that pas torque sensors give a more natural feel and presumably would improve the standing/hill start feeling(?)

So, can anyone advise if it's possible/sensible to use a pas torque sensor with a DIY hub motor bike?
It is, but rather than go by what you've heard, try the KT controller first, as you already have it. Most of those guys preaching about torque sensors have never tried a KT controller.

After-market controllers with torque sensors can be a bit crude, and the torque sensors are relatively heavy. You'd have to change to a square taper crankset too.

IIRC, Woosh sell a hub-motor kit with a torque sensor arrangement. I can't remember if they sell the torque sensor and controller separately.
 
Last edited:

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,882
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West Sx RH
If you want natural feel, ride a normal bike with no motor .
It's all pure nonsense which PAS motorised bike is more like a natural bike, answer none becasue they all have motor power.
 

Woosh

Trade Member
May 19, 2012
20,214
16,818
Southend on Sea
wooshbikes.co.uk
IIRC, Woosh sell a hub-motor kit with a torque sensor arrangement. I can't remember if they sell the torque sensor and controller separately.
we can't supply components (motor wheels, batteries, controllers, LCDs, sensors, cable looms etc) to individuals.
That would make support a nightmare.
We supply professionals with parts for out of warranty repairs though.
 

Bikes4two

Esteemed Pedelecer
Feb 21, 2020
997
428
Havant
It is, but rather than go by what you've heard, try the KT controller first, as you already have it. Most of those guys preaching about torque sensors have never tried a KT controller.
I am a great fan of the TSDZ2 mid drive system which is a torque sensing controller/motor as to me the assistance delivers power to the bike in an as near similar way as if I'd had younger legs transplanted :D.

Having said that I did fit a KT controller to a Pendleton Somerby (rear hub motor) back in July 2020 (link) and as I remember it, the ride feel was for me, much improved over the replaced cadence sensing controller.

I was not riding ebikes at that time so a direct comparison with a TSDZ2 wasn't on the cards and the Pendleton was sold on, but should I ever get to install a hub motor, I'd be very happy to give the KT kit a go, so as @saneagle says, fit the KT controller and see what you think
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
It is, but rather than go by what you've heard, try the KT controller first, as you already have it. Most of those guys preaching about torque sensors have never tried a KT controller.

After-market controllers with torque sensors can be a bit crude, and the torque sensors are relatively heavy. You'd have to change to a square taper crankset too.

IIRC, Woosh sell a hub-motor kit with a torque sensor arrangement. I can't remember if they sell the torque sensor and controller separately.
Thanks @saneagle.
You mean try the KT controller with a cadence sensor right? ...any advice on a good cadence sensor to get, or are they all similar?
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
If you want natural feel, ride a normal bike with no motor .
It's all pure nonsense which PAS motorised bike is more like a natural bike, answer none becasue they all have motor power.
I do have a normal bike, which I use regularly and enjoy very much.
In addition to my normal bike I'm building an e-bike and my post was seeking advice on PAS sensors with a DIY hub motor conversion. This is the conversion kits forum right?
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
I am a great fan of the TSDZ2 mid drive system which is a torque sensing controller/motor as to me the assistance delivers power to the bike in an as near similar way as if I'd had younger legs transplanted :D.

Having said that I did fit a KT controller to a Pendleton Somerby (rear hub motor) back in July 2020 (link) and as I remember it, the ride feel was for me, much improved over the replaced cadence sensing controller.

I was not riding ebikes at that time so a direct comparison with a TSDZ2 wasn't on the cards and the Pendleton was sold on, but should I ever get to install a hub motor, I'd be very happy to give the KT kit a go, so as @saneagle says, fit the KT controller and see what you think
Thanks @Bikes4two .
Your Pendleton project looks great. I've picked up lots of good info reading through the posts.
Now I'm even more confused though. Reading what you and @saneagle have said, and references in your Pendleton posts ("PAS - Without PAS "), is the implication that the KT controller doesn't need a PAS sensor? ...or am I missinterpretting it?
 
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saneagle

Esteemed Pedelecer
Oct 10, 2010
6,563
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Telford
Thanks @Bikes4two .
Your Pendleton project looks great. I've picked up lots of good info reading through the posts.
Now I'm even more confused though. Reading what you and @saneagle have said, and references in your Pendleton posts ("PAS - Without PAS "), is the implication that the KT controller doesn't need a PAS sensor? ...or am I missinterpretting it?
I think you are misunderstanding something. What I said is that it doesn't need a torque sensor because it works pretty nicely with a normal cadence pedal sensor. I would never go without a pedal sensor. If you didn't buy one with your kit, any normal magnet disc type will work, but best avoid ones with 12 magnets. For some strange reason people seem to ha e trouble getting the 12 magnet ones to work.
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
I think you are misunderstanding something. What I said is that it doesn't need a torque sensor because it works pretty nicely with a normal cadence pedal sensor. I would never go without a pedal sensor. If you didn't buy one with your kit, any normal magnet disc type will work, but best avoid ones with 12 magnets. For some strange reason people seem to ha e trouble getting the 12 magnet ones to work.
Thanks for the advice, much appreciated. I'll do some research on a cadence sensors with more than 12 magnets.
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
53296
Project so far. Once I get the PAS working I intend to remove the twist throttle.
It currently max's out at 22MPH, so my next task will be to figure out how to restrict it to 15.5MPH...
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
If your BB is hollowtech or sram equivalent then the best option is to by a BZ10C Pas combo.
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
If your BB is hollowtech or sram equivalent then the best option is to by a BZ10C Pas combo.
Thanks @Nealh. Those are harder to get in the UK, but I managed to get one on a longer leadtime and happy to wait as I'd rather go with a recomended one. Much appreciated.
 

peterjd

Pedelecer
Sep 18, 2019
213
52
Thanks @Nealh. Those are harder to get in the UK, but I managed to get one on a longer leadtime and happy to wait as I'd rather go with a recomended one. Much appreciated.
Just to answer your original question - yes it is possible to have a torque sensor with a hub drive since my Decathlon Riverside 500E has it (possibly combined with some cadence sensing). The sensors are housed in the bottom bracket with the hub in the rear wheel. I like the overall effect particularly in starting from a stop but it is not perfect and can produce a 'surge' effect in some circumstances. Since the bike is under an extended warranty I don't intend investigating further. Good luck with your project. Peter
 
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