Torque Sensor Bottom Bracket

[moses]

Hi everyone. I'd like to apologise in advance if this is answered elsewhere, I did have a look but couldn't find anything.

I currently have a CYC but am looking at hub kits. The CYC is too much for my daily ride. I'm looking at an OZO freeride 750w hub motor with a KT hailong case 22amp 48v controller, and an eggrider display (which I already have).

My question is, I've got really used to torque sensing, rather than cadence. Can the KT controller understand a torque sensing signal? The description says it's got a 'speed set of 1 to 4.2v' does this refer to torque readings?

Thank you.

 

[amberwolf]

I currently have a CYC but am looking at hub kits. The CYC is too much for my daily ride.

By "too much" do you just mean it is too powerful, too quick an acceleration, etc? Because it's usually relatively easy to decrease the power supplied by a system, lots easier than trying to replicate the way a system operates for you with a completely different system, if you like the way the present one works already.


Regarding KT controllers; I don't think with KT firmware that they do anything other than cadence, and not really even that--they only detect that you are pedalling (not how fast or how hard) and simply engage full power at the assist level you have chosen on the display.

There is OSFW open source firmware in threads by Casainho, Stancecoke, et al, that does have better capabilities; I don't know if it comes preloaded on any version of the KT controller you would end up getting with a kit.

 

[moses]

Amber wolf, I never go over 700w with the CYC, which isn't putting any strain on a 2750w setup. It's also very obvious that it's a DIY ebike. I get curious looks almost daily and have been eyed up by the police a couple of times, which has made me sweat. I'm not faulting the CYC, it's just too much.

Thank you for the KT information, I had thought as much. I think I'll have to bite the bullet and put up with an, in my opinion, ugly Cycle Anylist.

 

[amberwolf]

You don't have to put the CA where it can be seen.

Use the remote preset and/or digiaux controls, etc, to increment levels of assist (or whatever you set them to do), and put the device itself inside whatever you use to secure your battery, controller, etc from view.


If you want something small and innocuous looking, and you're not using more than 700w anyway, Bafang and others have small-diameter geared rear hubmotors that would be "hidden" more or less behind a disc brake rotor and the gear cluster. I don't recall the specific model numbers, but a bit of poking around for threads about "bafang" and "hub*" should find some of them. One possible search below:

https://endless-sphere.com/forums/search.php?keywords=bafang+hub*&terms=all&author=&sc=1&sf=firstpost&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

The "Jump" motors are all lower-power front motors, and a bit larger diameter than the ones I"m referring to, but are presently pretty cheap used from battery recycling centers.

 

[stancecoke]

I think I'll have to bite the bullet and put up with an, in my opinion, ugly Cycle Anylist.

There is a cheap 12FET Controller available at Aliexpress, that works with the torquesensor out of the box.
There is no need for an ugly and expensive CA.

https://aliexpress.com/item/1005002711701202.html

regards
stancecoke

 

[amberwolf]

Interesting--first one I've seen like that; glad they are beginning to sell them for DIY.

The details on that controller page say it works with their Erider torque sensor, which according to the details on their linked pages outputs a 1.5v-3v signal (like some throttles); this is different than some torque sensors, so it will depend on which torque sensor the OP already has whether that controller will work with it.

Some torque sensors start in the middle of the voltage range, around 2.5v, and go up or down from there depending on how much torque is applied (and possibly in which direction).


I'd venture that all throttle-only (or rather, any that don't require PAS for throttle to work) type controllers could work with that Erider torque sensor (though they may never reach full output if their throttle input maximum is higher, and may start running all the time if their minimum is lower, so it might require something to scale the voltage out of the Erider to match the throttle range of the controller). They wouldn't necessarily be able to read the cadence PAS sensor / direction signal part, but they could probably operate from the Erider's output as a throttle signal.

 

[stancecoke]

Some torque sensors start in the middle of the voltage range, around 2.5v, and go up or down from there depending on how much torque is applied (and possibly in which direction).

Our EBiCS firmware works on this controller, so you can configure it for any input range :wink:
I implemented support for the NCTE torque sensor just a few days ago
https://github.com/EBiCS/EBiCS_Firmware/tree/NCTE

regards
stancecoke

 

[amberwolf]

Our EBiCS firmware works on this controller, so you can configure it for any input range :wink:
I implemented support for the NCTE torque sensor just a few days ago
https://github.com/EBiCS/EBiCS_Firmware/tree/NCTE

Ah, well that makes an entirely different story with a happier ending.

To help people that don't know about your OSFW projects, I recommend that whenever you recommend a controller that can work with any of your OSFW you also note that ability and link it, like here.

 

[moses]

Thank you so much for the input and advice. I will definitely look into that AliExpress controller and that's a great idea about hiding the CA in a bag. Thank you.