Modifying to Torque Sensing

[JohnD135]

Hi All.
I am considering modifying my old cadence sensing ebike to torque sensing. I see that Woosh have a kit to do this, but I am concerned that my Bafang motor may be too old (2002) to be compatible. The connector is a nine pin, with seven small pins and two large. Woosh tell me that their kit is also nine pin, which is a good start. Has anyone experience in this area please?
Best regards, JohnD.

 

[saneagle]

Hi All.
I am considering modifying my old cadence sensing ebike to torque sensing. I see that Woosh have a kit to do this, but I am concerned that my Bafang motor may be too old (2002) to be compatible. The connector is a nine pin, with seven small pins and two large. Woosh tell me that their kit is also nine pin, which is a good start. Has anyone experience in this area please?
Best regards, JohnD.

All motors work the same as long as they have the 9-pin connector. What problem are you trying to solve with this idea? There may be other solutions. What controller and control panel do you have now.

 

[JohnD135]

I currently have an S-KU65 controller and an 810 control panel. This is cadence control. There are two drivers for a change. First, the controller probably needs changing since the drive produces a strange noise when it gets hot. I have reduced this effect by improving the thermal path to the frame, but it still happens on low speed hills. Second, I do long rides with a group. Sunday was 65 miles and with cadence i am not able to optimize the effort that I contribute to my speed. It is the opinion of other ebike riders that a torque controller can give less battery usage, provided of course, i put in the extra effort.
Good to hear that the motor will probably work and thanks for your response.

 

[RogerA]

I tried the Woosh torque sensor BB last year. Personally I couldn't get on with it, partly because I like to set a cut off speed below the legal maximum 25kph, and this kit wouldn't allow it. The discussion at the time is here.... https://www.pedelecs.co.uk/forum/threads/woosh-ts-bb-kit.46792/page-2#post-710245

If you're interested I have the kit that I bought (BB, controller and display - no battery or wheel) boxed up and will let you have it for £50 including postage (£100 new) . Just drop me a PM to discuss payment/posting. I think it only did about 80 miles before I removed it and went back to my KT current controller.

 

[saneagle]

I currently have an S-KU65 controller and an 810 control panel. This is cadence control. There are two drivers for a change. First, the controller probably needs changing since the drive produces a strange noise when it gets hot. I have reduced this effect by improving the thermal path to the frame, but it still happens on low speed hills. Second, I do long rides with a group. Sunday was 65 miles and with cadence i am not able to optimize the effort that I contribute to my speed. It is the opinion of other ebike riders that a torque controller can give less battery usage, provided of course, i put in the extra effort.
Good to hear that the motor will probably work and thanks for your response.

That's right. You can't get a longer range without pedalling harder.

I haven't tried the Woosh torque sensor, but i can say that all torque sensor systems are not born equal. It all depends on how clever the algorithms in the software are. Some Chinese ones just behave like a switch to give fixed power when you pedal. Some give two levels of power, depending on how hard you pedal, some (the worst type) give power in proportion to pedal effort, and some have really nice algorithms that work just like you would want them to, but they're mostly on OEM bikes.

The system I like most is the cadence sensor with a KT controller, which allows you to select one of 5 adjustable power levels whenever it detects pedalling. This allows you to pedal as hard or as easy as you want without being a slave to the control system. The system has a very fast response time to the cadence sensor - hardly any delay. It has another advantage that you can set up the throttle as a legal boost button. Whenever you press the lever, the controller jumps to level 5, which is great for roundabouts and short hills, rather than going up allthrough the levels and back again with the level select buttons.

Your KU65 uses speed control, so whenever you pedal it gives maximum power with a different cut-off speed from each assistance level selected, so it's not very efficient, and it's difficult to get the right mix of power and pedal effort. I can understand the advantage of changing it.

If you try the Woosh system, make sure you let us know how well it works, whether it makes you too tired or whether it actually increases your range.

 

[sjpt]

whether it makes you too tired or whether it actually increases your range.

Misread that (must be my age) as
whether it makes you too tired or whether it actually increases your age.

 

[Woosh]

This allows you to pedal as hard or as easy as you want without being a slave to the control system.

The most I have to do is to change the assist level. People get used to the way their controller reacts in no time at all.
you may like one controller best but virtually all ebike controllers let you pedal as hard as you like.
I have used a range of controllers from Lishui, KT, JYT, Ananda, Tongsheng, Bafang, etc. The difference is the degree of jerkiness or smoothness (if you prefer that point of view) in the transition when the motor increases or decreases power when changing the assist level but to be honest, a) that lasts a second or so, and b) you'll feel that change of power with any of them, including the Bosches. In my experience, they are all good and I have no problem varying pedalling effort as I want to.
I genuinely like the Kclamber torque sensor. It feels very proportional and does not make any noise when you push hard or put all your weight on the pedals, you get the exact feel like riding a normal unpowered bike except you may believe that you are back where you were in your twenties.

 

[saneagle]

The most I have to do is to change the assist level. People get used to the way their controller reacts in no time at all.
you may like one controller best but virtually all ebike controllers let you pedal as hard as you like.
I have used a range of controllers from Lishui, KT, JYT, Ananda, Tongsheng, Bafang, etc. The difference is the degree of jerkiness or smoothness (if you prefer that point of view) in the transition when the motor increases or decreases power when changing the assist level but to be honest, a) that lasts a second or so, and b) you'll feel that change of power with any of them, including the Bosches. In my experience, they are all good and I have no problem varying pedalling effort as I want to.
I genuinely like the Kclamber torque sensor. It feels very proportional and does not make any noise when you push hard or put all your weight on the pedals, you get the exact feel like riding a normal unpowered bike except you may believe that you are back where you were in your twenties.

That's sort of true, but not what you want. Take your Rambletta. You select level one, start to pedal, and it immediately goes to 8 mph with full power no matter how hard you pedal. Af5er that, you can pedal as hard as you want, but you get no assistance. You select level 2 and it surges up to a bit faster, then you repeat, and so on. It's almost impossible to get a comfortable blend of pedal effort and motor assistance. The high torque from the small wheels makes it a lot worse than on a bike with large wheels.

When Roger tested your torque sensor kit, he said that he couldn't get the power he wanted to match his pedal effort. It kept giving too much power. Does that mean your controller uses speed control instead of current control? If so, you need to change it.

 

[Woosh]

When Roger tested your torque sensor kit, he said that he couldn't get the power he wanted to match his pedal effort. It kept giving too much power. Does that mean your controller uses speed control instead of current control? If so, you need to change it.

Is it Roger S.?

 

[Peter.Bridge]

I've used the Woosh BBTS on on of my bikes - I thought it was very good. I particularly liked being able to turn the pedals with no motor assist as I changed down coming to a junction and its ability to do hill starts - the motor would kick on very quickly - faster than my KT. I'm sure it wasn't speed sensored - I watched the power on the LCD and it did seem proportional to the effort given, but I would get full power for the PAS level at (for me) moderate pedalling effort - but I'm big burly chap, The problem Roger A had, as I understand it, was that you couldn't set a max assist speed lower than 25 km/h, so for his use case it was assisting him at say 20km/h when he only wanted it to assist if his speed fell below 15km/h (not sure the speeds are correct but you get the idea)

I think the PAS levels were 20% 40% 60% 80% 100% of full power. I was running it at 48V 15A. I'm a big burly chap and do a lot of cycling in the North York Moors with some long steep (15%-20%) hills and the controller would occasionally overheat. I've moved to a KT 9 mosfet controller and don't have that problem (but obviously don't have the TS anymore)

 

[saneagle]

I've used the Woosh BBTS on on of my bikes - I thought it was very good. I particularly liked being able to turn the pedals with no motor assist as I changed down coming to a junction and its ability to do hill starts - the motor would kick on very quickly - faster than my KT. I'm sure it wasn't speed sensored - I watched the power on the LCD and it did seem proportional to the effort given, but I would get full power for the PAS level at (for me) moderate pedalling effort - but I'm big burly chap, The problem Roger A had, as I understand it, was that you couldn't set a max assist speed lower than 25 km/h, so for his use case it was assisting him at say 20km/h when he only wanted it to assist if his speed fell below 15km/h (not sure the speeds are correct but you get the idea)

I think the PAS levels were 20% 40% 60% 80% 100% of full power. I was running it at 48V 15A. I'm a big burly chap and do a lot of cycling in the North York Moors with some long steep (15%-20%) hills and the controller would occasionally overheat. I've moved to a KT 9 mosfet controller and don't have that problem (but obviously don't have the TS anymore)

That was only one complaint. The other was that he couldn't regulate the power to how he wanted it,which caused his range to go down, so he went back to a KT. The OP in this thread is asking about how to increase his range from what he has. What can you say about range, if you have any data, anecdotal or otherwise? I would have thought that if the torque sensor system has 5 levels of power, it should at least be the same as a KT.

 

[Woosh]

I would have thought that if the torque sensor system has 5 levels of power, it should at least be the same as a KT.

I wanted to get the feedback from your friend Roger, I have a Roger S. who got a TS kit in 2020. Peter Bridge has/had a newer (2023) and better model.
We can help Roger to upgrade his kit to the same sensor as Peter had.

 

[Peter.Bridge]

That was only one complaint. The other was that he couldn't regulate the power to how he wanted it,which caused his range to go down, so he went back to a KT. The OP in this thread is asking about how to increase his range from what he has. What can you say about range, if you have any data, anecdotal or otherwise? I would have thought that if the torque sensor system has 5 levels of power, it should at least be the same as a KT.

Psychologically I used to ride round in level 3 (which was 60% of full power I think) compared to level 3 on the KT (33% of full power) and a lot of the time I was pedalling moderately hard which the torque sensor translated to full power for that level ! So I get better range on the KT but don't get there as fast. I think there is also a trick to fitting the bottom bracket - if you fit it too tight it pre-loads the torque sensor. For gentle to moderate pedalling the torque applied did control the power - just for me when I was in my normal pedalling (which is possibly heavier than a lot of peoples) I was around about 100% of the available power for that level

 

[RogerA]

I wanted to get the feedback from your friend Roger, I have a Roger S. who got a TS kit in 2020. Peter Bridge has/had a newer (2023) and better model.
We can help Roger to upgrade his kit to the same sensor as Peter had.

Woosh. I have the same kit as Peter. If you look at the discussion linked to in post 4 you can see that we had a discussion about how to get the TS kit working. I fairly quickly went back to my KT kit as it allowed me to just use the assistance for hills without having to keep changing PAS levels all the time.

 

[Woosh]

Thank you.

 

[harrys]

Hi All.
My Bafang motor may be too old (2002) to be compatible. The connector is a nine pin, with seven small pins and two large. Woosh tell me that their kit is also nine pin, which is a good start. Has anyone experience in this area please?

I hope that was a typing mistake and you mean 9 pins with three large ones, but a bike motor from 2002 is also pretty old.

There are lot more 9 pin connectors these days,but this was pretty common 10 years ago and is still used on lower current motors.

 

[JohnD135]

Concerning Harrys last comment. I went back and checked and i was mistaken. I have three large pins. I claim old age and poor eye sight! It seems to me that torque sensing, if it functions lineally, would work best with a motor at the crank. I have a rear motor and so every time i change gear, in response to a hill, the sensor would reduce the torque. Which is just what I don't need! I have now realized that torque sensing was recommended to me by someone with a motor at the crank. Have I understood this correctly?

 

[saneagle]

Concerning Harrys last comment. I went back and checked and i was mistaken. I have three large pins. I claim old age and poor eye sight! It seems to me that torque sensing, if it functions lineally, would work best with a motor at the crank. I have a rear motor and so every time i change gear, in response to a hill, the sensor would reduce the torque. Which is just what I don't need! I have now realized that torque sensing was recommended to me by someone with a motor at the crank. Have I understood this correctly?

It makes no difference what type of motor or where the motor is. It's all down to how good the algorithms in the controller are. Your original ones are crappy, so you need a controller with better ones. The type of sensor doesn't make a massive difference, it's what the controller does with it that matters.

 

[Woosh]

A good torque sensor helps to keep your joins supple and in good shape, and your body to retain and improve its muscle mass much more than a cadence sensor, so it makes a difference.
I don't normally use the throttle with my Tongsheng 85TS torque sensor bike because where I live but if I have to tackle anything too steep, the throttle will take care of that.

 

[saneagle]

A good torque sensor helps to keep your joins supple and in good shape, and your body to retain and improve its muscle mass much more than a cadence sensor, so it makes a difference.
I don't normally use the throttle with my Tongsheng 85TS torque sensor bike because where I live but if I have to tackle anything too steep, the throttle will take care of that.

It's not the sensor that does that. It's the power algorithms in the controller. A cadence sensor with speed control is really bad for that, and so is a torque sensor with speed control.