Looking for controller for torque PAS and throttle

[jason701802]

I'm looking to upgrade my bike to support throttle and torque PAS. Supporting regen would also be nice but isn't a requirement. My current setup is a 48V "1000W" direct drive rear hub motor with a throttle only controller.

The torque sensor seems like the easy part. The ERider(?) T17 (https://www.aliexpress.us/item/3256802600006779.html) has quadrature PAS for backpedal detection and seems to be well liked

The controller is where I'm getting hung up. A Lishui controller with custom firmware seems like an ideal solution (although I'm a little concerned about the 12A/500W continuous rating for my "1000W" motor), but it seems like Lishui controllers are now potted based on the latest review here: https://www.aliexpress.us/item/3256802525386450.html. The potting would make it impossible to reflash the controller or wire up the throttle. Is there anywhere else to get a non-potted controller?
I also looked at the cycle analyst 3, but it's pretty pricey and I really don't like the display.
A KT controller with custom firmware also seems like an option, but I'm a little concerned about the state of the firmware as it looks like no one currently owns it or wants to over it over.

Any advice on what controller to use would be appreciated.

 

[richj8990]

There is stuff like this but it's hit-and-miss IMO ---

https://www.elecycles.com/electric-bike-torque-sensor-kit.html

EUNORAU ENA 36V350W Controller System With torque sensor

This is the controller sets only for EUNORAU 36V350W conversion kit, please check carefully before order.This type of sensoris based on measurement of chain tension, with designated mounting angle, being compatible with standard bicycle chain ring/crank arm. It has dual torque sensing with 24...

eunorau-ebike.com

This may be the best option (and I may actually try it later too!):

Brand New E-bike Axle Replacement Black Electric Bicycles For Bafang Moto | eBay

Find many great new & used options and get the best deals for Brand New E-bike Axle Replacement Black Electric Bicycles For Bafang Moto at the best online prices at eBay! Free shipping for many products!

www.ebay.com

*Suitable for bafang series motors，can not be installed on the center motor, if you are not the Bafang torque controller can not be used, the plug is 6PIN plug. The opening width is 73mm, only an additional washer can be installed on the 68mm frame, and the total length of the central axle is 148mm




I think what they mean is that the Bafang BSSxx has a fixed bb axle attached to the motor, so you obviously can't use this with a Bafang Mid-drive. But you probably can with a double-chained mid-drive that has a disconnected motor. Probably. For the controller I think something like a C850 will work but also maybe a KT LCD series (but remember imitation torque is not torque-sensing). Others would know better about what controller has torque-sensing options, but it's worth trying.

Later this fall I may try this with a different controller (what I'd do is first buy the torque sensor and make sure it has 6 pins, then match that up along with the battery and motor pins to a compatible controller). See what happens. I would really like to do this because cadence-based PAS cannot work with my current mid-drive setup.

 

[jason701802]

That first controller looks like it only supports torque input, not throttle as well.

I also saw what I think is the same Bafang torque sensor, but I couldn't find a pinout to determine if it's a CAN device or an analog device.

I didn't realize Bafang made controllers in a form-factor suitable for a rear hub motor. Do any of them support throttle and torque? I'll have more time to look this evening, but the only one I see that support both in a quick search is this 36V250W controller: https://www.aliexpress.us/item/3256805583083350.html

 

[E-HP]

I've opted to go the CA route. I don't really care about displays since I only care about the data, and to check my speed if I'm around people or cops. The advantage is I have more flexibility in getting a controller that does what I want, rather than choosing from the very slim selection of controllers that accept a torque PAS input. The CA isn't expensive, if you consider the CA and controller as a combination, since the CA will work with any cheap dumb controller, and provide the functionality of an expensive one.
Be careful in your selection of the sensor. The Erider is a good choice, but others, like the NCTE only measure torque off the left crank, and since I usually start from a stop using my right leg, that wasn't going to work for me. I researched the torque PAS stuff for over a year, and that's where I ended up. The KT open source was my other choice, but then I'm locked into a KT controller, and while that's not bad, the KT's are a little weak in the phase amp area for what I'm looking for.

 

[richj8990]

I've opted to go the CA route. I don't really care about displays since I only care about the data, and to check my speed if I'm around people or cops. The advantage is I have more flexibility in getting a controller that does what I want, rather than choosing from the very slim selection of controllers that accept a torque PAS input. The CA isn't expensive, if you consider the CA and controller as a combination, since the CA will work with any cheap dumb controller, and provide the functionality of an expensive one.
Be careful in your selection of the sensor. The Erider is a good choice, but others, like the NCTE only measure torque off the left crank, and since I usually start from a stop using my right leg, that wasn't going to work for me. I researched the torque PAS stuff for over a year, and that's where I ended up. The KT open source was my other choice, but then I'm locked into a KT controller, and while that's not bad, the KT's are a little weak in the phase amp area for what I'm looking for.

from the Grin site:

Fischer AG Torque Sensing BB, 127mm ($60 USD, normally $150)​

Excellent Deal Bottom Bracket Torque Sensor from Fischer-AG. Senses Left Crank Pedal Force Similar to THUN/NCTE and Requires Drilling Hole in Bottom Bracket for Cable Exit. 127mm Square Taper Spindle and 68mm BB Width.


It says it has an adapter plug for JST/SM --- so that's 3-pin that plugs into the PAS female plug on a generic controller?

Requires drilling hole in bottom bracket for cable exit. That's a thick cord to drill a big hole in the frame for. So close, yet so far away.

 

[richj8990]

That first controller looks like it only supports torque input, not throttle as well.

I also saw what I think is the same Bafang torque sensor, but I couldn't find a pinout to determine if it's a CAN device or an analog device.

I didn't realize Bafang made controllers in a form-factor suitable for a rear hub motor. Do any of them support throttle and torque? I'll have more time to look this evening, but the only one I see that support both in a quick search is this 36V250W controller: https://www.aliexpress.us/item/3256805583083350.html

I noticed the few controllers that actually say Torque Sensor on them are not more than 350W / 13A. Which is a bit of a bummer. Tongsheng has 500W but they don't use a stand-alone bb axle. I understand that these manufacturers are playing to a market that's lower-powered 205W stuff especially for Europe, but you'd think they would make a stronger controller and have more DIY options for torque sensing bb's. Maybe they will later, for now it looks like most of them are the entire kit or complete bike.

 

[jason701802]

A CA is more expensive than a Lishui controller, which does everything I want (if I can flash custom FW), and I'd still need to buy a new controller to get regen. It also requires running quite a few more wires up to my handlebars, which is messy and means more things to break.

Can the buttons the CA be configured to control the assist level? That's something I'd like to be able to control while I'm riding.

Do Bafang have/support torque sensors on the CAN bus (EB-BUS)? The listings I see only mention a display and throttle, but the listings are not the most detailed.

 

[E-HP]

A CA is more expensive than a Lishui controller, which does everything I want (if I can flash custom FW), and I'd still need to buy a new controller to get regen. It also requires running quite a few more wires up to my handlebars, which is messy and means more things to break.

Can the buttons the CA be configured to control the assist level? That's something I'd like to be able to control while I'm riding.

Do Bafang have/support torque sensors on the CAN bus (EB-BUS)? The listings I see only mention a display and throttle, but the listings are not the most detailed.

If the Lishui controller does what you need, then problem solved!

FYI the CA reduces wires to the handlebars, if you use brake cutoffs or have a throttle, since those connect directly to the CA. A PAS cable and the CA cable go from the handlebars to the bottom bracket and controller, respectively.

You can configure the CA buttons on the digital input to control anything, including PAS levels, digitally, or using the analog input to control anything with a pot; or both. The torque PAS also provides a cadence signal, so you can use the CA to adjust assistance as your cadence changes. I use that to increase assistance automatically when downshifting for a hill. I see you're in the bay area, so I assume you aren't riding on the hills if you're considering a 500W controller.

The CA is a good choice if you are planning upgrades or plan on implementing some of its features in the future. If you don't need the flexibility, there are cheaper one and done solutions.

 

[jason701802]

The Lishui controller only does what I need if I can find one that isn't potted or it's possible to work around the potting. I don't want to take a gamble on that unless someone else has some experience with it.
By my count of wires running from the frame to handlebars, the CA adds 6 wires for PAS, 2+ wires for the shunt (unless this is optional), and only saves 2 wires for the brake sensor. The throttle signal is the same either way, in one case it goes directly to the throttle, in the other it goes to the CA.
Perusing the manual more, I see that I could add external up/down buttons to control assist, this would solve my need, but is just one more thing to buy and wire up.

I'm looking for either a cheap controller that I can put custom FW on (I've found the KT and Lishui projects, I imagine there are more floating around) or one of those cheaper "one-and-done" solutions. I just haven't been able to find one that supports torque and throttle.

If I do go the CA route, do you have any recommendations for controllers that support regen? Baserunner/phaserunner are obviously an option, but completely blow the budget.

EDIT: I also see the VESC project. I haven't looked too deeply, but if I understand it correctly, it doesn't have enough inputs to support anything other than a throttle and I'd need a separate controller to handle the sensor inputs.