Torque sensing bracket + rear hub + small 250w hub, what's the best combo for this build?

[woody27]

Hi All

Been reading here for ages and will now take the plunge, still slightly confuse though so am looking for a little help from the pros.

Have a 90's Marin steel to convert with the following use / constraints:
- Commute (5mi each way), mostly flat, some red lights start and stop (London) - 80%
- Assist with child bike trailer, from time to time - 20%
- It needs to be UK road legal: 250w rated and no throttle, for many reasons and mainly my peace of mind (no need to debate this here). Beside, I really don't need a lot of assist, currently i'm without motor and can deal, just need a little push for wind / stop start and trailer.
- Torque sensor absolutely

I could go with a TSDZ2B or maybe the upcoming to7, but am keen to try and go for hub with a battery in the seatpost or a seatpost bag for max discretion. Beside I read that bikes like the onerideup and volt with BB torque sensor are working very well so am keen to try and do this.
motors could be a Q100/Akm100/G310/Swx02 or any other you think may be appropriate.

With that in mind, what do I need?

- Bottom bracket: eRider t17?
- Controller: KT? grintech (they are expensive and wondering if worth it for my use)?
- cycle analyst: do I need one?

Thanks a ton!

EDIT: preferably would buy parts in Europe but if need to import for North America so be it..

 

[stancecoke]

With that in mind, what do I need?

There is a complete set at Eunorau:

Eunorau 36V350W Rear Freewheel Motor With Torque Sensor Conversion Kit

EUNORAU hub motor kit have 36V250W version,36V350W version,48V500W version and 48V1000W version,250W version, 350W version and 500W version is for street use, 1000W version is for off road use,250W kit with front wheel motor,sin-wave controller and colorful LCD display with USB plug, 350w kit...

eunorau-ebike.com

But I don't know any user report to this set.

I prefer the components from Phoebe Liu at AliExpress.

They have a hubmotor with an integrated torquesensor also.

 

[woody27]

Wow, this really helps me a lot, have you ordered from Phoebe Liu before?! There are A LOT of parts on this shop. It's a PITA to navigate aliexpress, I spent hours on it and have not found this shop (nor the torque sensors) before. Thank you.

Any recommendation for the controller?
Also, do I need a cycle analyst or can I plug the torque sensor directly into any random controller (like KT) with a socket for the torque sensor?

 

[E-HP]

Wow, this really helps me a lot, have you ordered from Phoebe Liu before?! There are A LOT of parts on this shop. It's a PITA to navigate aliexpress, I spent hours on it and have not found this shop (nor the torque sensors) before. Thank you.

Any recommendation for the controller?
Also, do I need a cycle analyst or can I plug the torque sensor directly into any random controller (like KT) with a socket for the torque sensor?

I'm sure you've been doing your research, but just making sure that you know that all torque sensors are not created equal. The eRider is nice in that it senses torque on both the left and right cranks, while some only measure torque from the left crank. That was a bigger deal for me, since I generally start off using my right leg, but it really depends on how you use your bike.

You need a controller that accepts a torque sensing PAS, which is rarer, since most only work with cadence sensing PAS, or something like the CA between the torque sensor and controller. With the latter, any "dumb" controller will work. The other option is to load the open source firmware into a KT display (e.g. LCD3 etc.), that adds torque sensing capabilities as well as other features.

 

[woody27]

Thank you HP, really good info. Love the photos of your bike and the bay, where I did try ebikes for the first time years ago on a trip to sausalito.

So to recap I now need to get:

1. Either a controller with a torque sensing PAS connection
2. Either ANY controller with the cycle analyst, which could be re-used for future projects so this is tempting.

If I use the cycle analyst (solution 2) can I literally choose ANY controller? If that is the case I might as well look for a cheap 15A or 17A controller (should let 540 or 612w flow into the motor) like this one?

Could it also work for those controllers integrated in the battery holder like ("bottle" type) or am I dreaming? the smaller the better for me, I am looking for low assist and stealth.

 

[E-HP]

For #2, the CA interfaces with the controller via a throttle signal input. You don't need to have a throttle, but the controller needs a throttle input, which most do. For the level of power you're going to be using, there are a few options for small controllers, including the integrated ones, but I'm not familiar with what is available in Europe.

 

[amberwolf]

If I use the cycle analyst (solution 2) can I literally choose ANY controller?

The controller must be able to operate in throttle-only mode.

Meaning, it must have a throttle input, and it must *not* require pedalling / PAS to be operating. (or else you will have to create a connection from your PAS sensor to the controller as well as the CA, or have a separate PAS sensor for the controller from the one the CA uses, complicating the system and making more possible failure modes).

The CA is a powerful tool...but only as powerful and useful as the user-setup of it. It's not plug and play, and has quite a bit of setup you must do, after you decide what you want it to do and how you want it to do that. I recommend that if you have not already, you read the whole page at V3 Cycle Analyst Info Page and go thru the manual for it that is there. That way you have some better idea of what you're getting into and what you will need to setup.

 

[stancecoke]

Any recommendation for the controller?

The Lishui 12FET is a good choice, a firmware-update may be necessary to get a access to relevant parameter settings.

Also, do I need a cycle analyst

No, the cycle analyst is a relict from times, where no controllers with built in torquesensor function were available.

There is a long thread about the Lishui 12 FET with torque sensor function in the German forum.

Could it also work for those controllers integrated in the battery holder like ("bottle" type) or am I dreaming?

You can use an integrated Lishui FOC controller with the open source firmware, but there is some soldering necessary.

EBS Controller 36V 15A FOC integriert in PurePower-V3-Akkuhalterung

Das Produkt ist unter diesem Link kaufbar: EBS Controller 36V 15A FOC integriert in PurePower-V3-Akkuhalterung 1) Folgende…

www.ebike-solutions.com

regards
stancecoke

 

[woody27]

Thanks to the three of you, really valuable information.

Regarding the solution without cycle analyst, unless I miss something may require:

1. to open the controller and remove the weatherproof substance to access the circuit to flash the firmware, okay looks feasible.
2. to "solder the throttle signal to SP (?) and add a 5V and GND to it" so that the torque sensing works, okay looks feasible if I know exactly what two pieces to solder.
3. And then it seems there still needs to be a lot of time fiddling with the firmware

I am starting to realise the cycle analyst adds value to newbies like me. It seems to make things a lot more plug and play (or plug, set things up on the display, and play). My main goal is to get out on the bike and ride, modding a controller may be a new hobby for the winter, maybe.

I think I will bite the bullet and go the CA route, and hide it in the battery bag.

Would this controller work with the eRider and cycle analyst? The seller says that they use it on their own bike, that it's wired to a crank sensor and a thumb throttle, they also said they used it with only a thumb throttle in the past without pedalling.

 

[stancecoke]

Regarding the solution without cycle analyst, unless I miss something may require:
1. to open the controller and remove ...
2. to "solder the throttle signal ....

No, you don't have to open the controller or have to solder anything with the Phoebe Liu set. Just plug in the torquesensor and start riding.
If you are not satisfied with the original firmware, you have the possibility to flash the open source firmware and fine tune the system.

And then it seems there still needs to be a lot of time fiddling with the firmware

I guess it's not much difference in fiddling between CA and the OSF for a Lishui Both will be a challenge for a newbie .

The CA is a powerful tool...but only as powerful and useful as the user-setup of it. It's not plug and play, and has quite a bit of setup you must do, after you decide what you want it to do and how you want it to do that

If you want it plug and play, then buy the set from Phoebe Liu or from Eunorau.
I don't recomment a Kunteng controller, they are completely outdated. No FOC, no sensorless sinusoidal commutation....

regards
stancecoke

 

[Chalo]

I've said it before and I'll surely say it again, but rear hub motors often break their side covers under vigorous pedaling, and especially from having mid drive power stuffed through their freewheels. If you want to combine a hub motor and a mid drive, use a front hub and bypass that problem.

 

[E-HP]

I've said it before and I'll surely say it again, but rear hub motors often break their side covers under vigorous pedaling, and especially from having mid drive power stuffed through their freewheels. If you want to combine a hub motor and a mid drive, use a front hub and bypass that problem.

Wrong thread??

 

[Chalo]

Wrong thread??

It's right in the title, mid drive and rear hub. Bad combo.

 

[woody27]

No, you don't have to open the controller or have to solder anything with the Phoebe Liu set. Just plug in the torquesensor and start riding.
If you are not satisfied with the original firmware, you have the possibility to flash the open source firmware and fine tune the system.

Okay I am doing more research about the solution without the CA, with controller only:

I understand that the torque sensor can be plugged into the Lishui (sold by Phoebe Liu) controller, so it is plug and play, but the assist is not great, so you have made a new firmware with different torque sensing parameters (this is really remarkable and I admire your skills to do this from scratch). This is done by plugging the display port on the controller to the usb tool. I also understand that essentially the CA is a tool which allows to modify the torque sensing setting immediately from the display, without flashing any firmware. Let me know if I misunderstood anything.

But then what is the benefit of using the Lishui controller if in order to get a smooth torque sensing experience the firmware flashing is needed? How is it different than flashing the firmware for a KT to get it to work nicely with the torque sensor?

I wish there would be a controller out there where you'd plug the torque sensor and you could ride just like a commercial ebike (like the rideoneup). After all, they must use similar components.

Maybe the mid-drive where everything is already installed and working outside of the box was not a bad idea after all.

 

[E-HP]

It's right in the title, mid drive and rear hub. Bad combo.

Maybe the title changed?
"Torque sensing bracket + rear hub + small 250w hub, what's the best combo for this build?"

 

[stancecoke]

I wish there would be a controller out there where you'd plug the torque sensor and you could ride just like a commercial ebike

maybe the Keyde P110 system is what you are looking for. Very simple to install, just one wire from the motor to the battery. No need to change the bottom bracket....

P110 motor is our new developed rear motor. It integrated sine wave controller, speed sensor, torque sensor and slope sensors.
The highly intergraded structure reduces installation space and line loss., and makes assembly more convenient.

regards
stancecoke

 

[cubicapple]

The other option is to load the open source firmware into a KT display (e.g. LCD3 etc.), that adds torque sensing capabilities as well as other features.

Hi -- I am also trying to find a solution to retrofit a torque sensor to an ebike with a rear hub motor. I am in the very beginning of the journey, on the silly questions square yet. Could you please elaborate on this option with the display firmware? Do I understand correctly that with the reflashed firmware the KT display turn into something similar to CA? How do I plug the torque sensor? Directly to the display?

 

[E-HP]

Hi -- I am also trying to find a solution to retrofit a torque sensor to an ebike with a rear hub motor. I am in the very beginning of the journey, on the silly questions square yet. Could you please elaborate on this option with the display firmware? Do I understand correctly that with the reflashed firmware the KT display turn into something similar to CA? How do I plug the torque sensor? Directly to the display?

There are several threads if you search on KT opensource firmware.
Here's one:

KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)

This OpenSource firmware/embedded software runs on the BMSBattery S/Kunteng KT motor controllers. The main advantages of this controllers are: 1. sine wave/"FOC": motors run silent and very efficient 2. cheap: starting at 20€ 3. widely available: many online shops sell them and ship to worldwide...

endless-sphere.com