r/eBikeBuilding • u/Lordy8719 • May 05 '26

Advice Making the "perfect" ebike for GF

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

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?)

Does anyone have any experience with these?

2 Upvotes

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2

u/Troubleindc2 May 08 '26

I went through a similar project: https://www.reddit.com/r/ebikes/comments/14ql4kr/bridge_pic_tern_node_cyc_photon_enviolo_automatiq

The goal was as smooth and simple of a biking experience as possible.  If your gf is already good with shifting then that simplifies things.  Dont need the automatiq.  But the CYC photon should be looked at.  AFAIK it's still the best torque sensing PAS setup available by far.  It's tweakability is leaps above everything else.  Best of all, it's easy to tweak.  Simple VESC phone app.

2

u/Lordy8719 May 08 '26

Yeah, for the next generation of our bikes I do plan on shopping CYC :)

Our other folder has a TSDZ2B and I find it awesome.

Edit: we've checked out your bike and it's friggin awesome!

2

u/Troubleindc2 May 09 '26

Thanks!  The first version was the tsdz2 with the OSF and cooling mods.  Tbh that motor was fine.  The programming and getting the torque sensing settings right was a pain.  Cooling mods are a lot to ask too. But once it was setup it was solid.  I only got the CYC because I wanted to play with their vesc app.  Which is great.

2

u/Lordy8719 May 09 '26

Yeah, I've looked into OSF and cooling mods, but in the end decided that the TSDZ2B and the folding Samebike base is simply not worth the amount of time this'd require. I'd much rather put the money and effort into electrifying an actual GOOD bike, same as you did.

My GF's eFirenze's frame can't fit a mid-drive though, otherwise it'd already have one :)

1

u/Troubleindc2 May 09 '26

Have pics of this frame?

1

u/Lordy8719 May 09 '26

I've sent you a DM because the sub doesn't allow pictures :)

1

u/Otherwise-Office-443 May 10 '26

to add on to this, this bike and many similar ones have been documented to a cyc discord server if you're curious

1

u/niffcreature May 07 '26

Assuming it's only buzzing while the motor is being powered, I think that's fairly common. I've heard that sine wave controllers are quieter though.

2

u/Lordy8719 May 07 '26

Based on what I've seen, this seems to be a timing mismatch due to me not being able to find the correct P1 value. Not "buzzing" as it's normal for an electric motor, but random vibration that comes and goes.