Upgrading a Chinese folder

[LordyHun]

Hi Everyone!
My girlfriend has "inherited" my old EbikeSpecial eFirenze 20" folder from me about 2 years ago, and she's been having a blast with it.
She loves the form factor, which is perfect for a petite woman weighting 48kg, I've did some necessary upgrades over the years: hydraulic brakes, Shimano Altus rapid trigger shifter, etc.

An issue she had with the super basic controller (generic controller with G51 screen) was that PAS was very erratic and since she doesn't have much mass, whenever PAS decided to engage, the bike essentially JUMPED, which was super dangerous when we were exploring on some bike trails in Croatia.

So after we got back from our trip, I've started rebuilding the bike. I've first bought a KT sine wave controller + display + sensors set. Imitation torque is far better than the generic controller was, takeoff is soft, easy to control.

However, there's some weird buzzing that keeps occurring at random with the KT controller. I've replaced the controller but it happens with the new one too. It seems to be related to the P1 parameter.

What I did for troubleshooting:

• Built a test harness and checked if all hall sensors and phase wires are well connected and the order is right.
• I've tested the Hall sensors in the motor
• I've tested P1 from 50 to 120 and settled with the one that made the motor run the best. While testing, the hub was disassembled and I was just holding it in one hand while engaging the throttle with the other to "feel" if it's running smoothly
• (bearings in the wheel have been replaced with Enduro bearings, that didn't hurt but it didn't fix the buzzing. And yes, I've cleaned the motor and applied a generous amount of grease)

My GF says that this is not a dealbreaker but I like to do quality work with my tinkering.
Recently I've seen that Lishui apparently makes controllers with torque sensors (T15, T17 and the likes) and I've been thinking of trying one out.
The system I'd like to integrate it with:

• "XOFO 7.820.100A5" 36V 250W hub motor (9 pin Julet plug)
• 36V battery in great condition
• hydraulic brakes with 2-pin brake cutoff signals
• BB size is a bit odd, BB83

The controller kit I've found:

• T15 or T17 BB83 torque sensor
• Lishui LSW1728-1-1F controller with S2 display
• (don't know what else I might need, maybe a throttle and compatible lights?)

I've reached out to the seller of the torque sensor and controller to ask if it has a light output / throttle input and they've said:
"has two models,"
"one --with throttle and torque sensor wire, no low brake wire"
"second, --has low brake and torque sensor wire, and light wire,"
"so choose your preference"

(personally I'd choose the one with the light wire - a throttle is quite optional if you have a torque sensor)

Experts of Endless Sphere, should I try the Lishui upgrade, or should I just buy/build an actual quality bike in the long term?

 

[RunForTheHills]

This is a DIY forum, so most people here would buy the kit rather than a factory ebike. I don't know anything about that bike, but I am personally not a fan of 20" folders. So I would get a different bike to put the kit on.

Grin also sells a controller (Phaserunner or Baserunner) that will support throttle, brake sensor, and torque sensor. If you get the Superharness it has rear and front light hookups too. However, you can make your own light wiring harness very easily and connect it directly to the ebike battery. I don't think that is an issue either. You can get lights that work on battery voltage pretty inexpensively.

 

[neptronix]

Yeah, if you want PAS tunability, torque sensing, etc, grin's controllers specialize in that... i don't know about lishui's or KT's as i've never used them, maybe someone can chime in.

PAS is configured in stupid ways on all cheap controllers i've tried it on. Rarely does it work well, torque sensing is the way if you can get it.

 

[E-HP]

Experts of Endless Sphere, should I try the Lishui upgrade, or should I just buy/build an actual quality bike in the long term?

I’d argue that the ES member with the most knowledge/experience with Lishui controllers and torque sensors is probably stancecoke.
Doing a search on “Lishui torque”, and his member id yields a few results that may provide some info on your question.

Google search results

endless-sphere.com

PS. I’d personally want the torque sensors and throttle combo since I don’t need the cutoffs, especially with the torque sensor. I don’t have a Lishui, so don’t know how quickly assist stops after pedaling stops, but mine cuts out right away, and I’m confident that my brakes can stall the motor if something went wrong.

 

[LordyHun]

Thank you all for your answers!
I've noticed that I've forgot to tell that we're living in Europe (250W/25kph limits) and the reason we're using 20" folders is that I can fit two of them into our trunk while we're traveling the Mediterranean. They're quite practical for our use.

Although I've heard great things about Grin's products, getting a Phaserunner would be quite expensive (shipping and taxes would add a markup of ~50%) and it's far too big to fit comfortably on a small bike. (it a 90Amp controller, that's moped-class here)

What got me to start looking into Lishui electronics was actually Berm Peak Seth's video when he tried to "jailbreak" a pay-to-ride bicycle. A big issue is that we're planning to leave for our next trip in a month so I can't order a Lishui set to try it out because it wouldn't arrive in time...

Another option would be to just buy a Cube Fold Hybrid for her, but that'd lock me into the Bosch ecosystem, or maybe I could get an Eclipse and put a mid-drive on that one.

 

[lnanek]

Grin has a set of tiny controllers called the Baserunner too.

 

[docw009]

My wife and I put over 5000 miles each on a pair of 20" folders that I converted with 20A KT sinewave controllers and Q100H rear hubmotors. I mostly ran them on 36V, The motor sound is a fairly soft buzzing. The pedaling feel seemed fine to me. I have torque sense mid drives for comparison, and small wheels spin so easy that I don't think it's worth the expense.

Woosh in the UK sells hub motor based T/S kits He might sell one w/o the motor,

 

[LordyHun]

My wife and I put over 5000 miles each on a pair of 20" folders that I converted with 20A KT sinewave controllers and Q100H rear hubmotors. I mostly ran them on 36V, The motor sound is a fairly soft buzzing. The pedaling feel seemed fine to me. I have torque sense mid drives for comparison, and small wheels spin so easy that I don't think it's worth the expense.

Woosh in the UK sells hub motor based T/S kits He might sell one w/o the motor,

I'm at least 80% sure that those controllers being sold by Woosh are rebranded Lishui controllers

 

[LordyHun]

Grin has a set of tiny controllers called the Baserunner too.

Those look awesome, I'll check how easily I could integrate it to the current system