Tongsheng TSDZ8 Firmware Options and Flashing Questions

[MK_1981]

can you confirm for me with your endless knowledge, are magnetic brake sensors for hydro brakes, and gear shift sensor for bafang (3pin, yellow), also compatible with tong sheng system, specificaly TSDZ8 motor?

thanks

 

[Greg Watts]

can you confirm for me with your endless knowledge, are magnetic brake sensors for hydro brakes, and gear shift sensor for bafang (3pin, yellow), also compatible with tong sheng system, specificaly TSDZ8 motor? thanks

@MK_1981 Short answer: yes, mostly, with one caveat. The 3-pin yellow Julet/higgo connectors Bafang uses are the de facto standard across the budget Chinese mid-drive world, and Tongsheng adopted the same plug pattern on the TSDZ2 and carried it over to the TSDZ8. So generic magnetic brake sensors (the reed-switch type with the magnet that clamps to the lever) and the inline gear shift sensor sold for Bafang BBS01/02/HD will physically plug into the TSDZ8 harness without an adapter.

The caveat is the gear sensor. The TSDZ8 controller does honour a shift-interrupt signal (briefly cuts power when the sensor closes), but the behaviour is firmer on OSF/open-source firmware than it is on the stock Tongsheng firmware, where some users report it being a bit half-hearted. If you're running stock firmware and the shift cut feels weak, that's why - flashing OSF tends to sort it. Brake sensors work fine on stock firmware, no drama there.

One practical note: check pin order before you plug in. 99% of the time it's identical, but I've seen the odd Aliexpress sensor with pins 1 and 3 swapped, which will either do nothing or trigger the cutoff permanently. A multimeter on continuity for ten seconds saves a lot of head-scratching.

 

[MK_1981]

when you say ..."trigger the cutoff permanently", do you meen permanently, as in while it's connected, or permanently like in ruined system ?

not sure I understand how to check if it's proper.

 

[Greg Watts]

when you say ..."trigger the cutoff permanently", do you meen permanently, as in while it's connected, or permanently like in ruined system ?

@MK_1981 Ha, no, breathe easy. Permanently as in "for as long as it's plugged in like that" - not permanently as in "your motor is now an expensive paperweight."

What happens with swapped pins is the controller just sees a constant shift-cut signal, so it thinks you're forever mid-gear-change and refuses to deliver power. Unplug the sensor, or fix the pin order, and the system goes back to normal immediately. No magic smoke, no fried controller, no tears.

The TSDZ8's shift sensor input is just a simple low-voltage signal line looking for a momentary contact closure. Wiring it wrong won't damage anything on either end, it'll just behave stupidly until you sort it. Same goes for the brake sensors - worst case is the bike thinks the brakes are permanently pulled and gives you no assist.

Cheap to test, easy to fix, nothing to fear. That's the joy of these open Julet connector systems: very hard to actually break things by plugging stuff in wrong.

 

[MK_1981]

One other question, if I may,
Do you have any comments/input/confirmation... for this combo:

TSDz8 motor + bike KROSS HEXAGON 4.0 (M size, 29" tires) + TSDZ8 chainring adapter 130BCD 11mm offset + TSDZ8 narrow wide chainring 38T + TSDZ8 chainring cover 130BCD + TSDZ8 chainring bolts 7mm - 12mm (for use with cover) + KMC e8 EPT chain.

 

[Greg Watts]

@MK_1981 Right, let's run through the shopping list. Most of it stacks up, but there's a fundamental compatibility issue worth flagging before you spend the money.

The bike: the Kross Hexagon 4.0 is a 29er hardtail, but unfortunately the TSDZ8 motor is not compatible with this frame. The hydro brake lines and derailleur wire outlets run underneath the frame in a way that conflicts with the motor's design, making this combination unsuitable regardless of the other components you choose. So the motor simply won't work on this bike, full stop — no amount of adapter juggling will resolve it.

The chainring stack you've listed — the ebikestuff combo with the 130BCD adapter at 11mm offset, 38T narrow wide ring, matching cover and bolts — is otherwise the right approach for the TSDZ8 in general. Two things to be aware of for future reference when you find a compatible frame. First, with a flat 130BCD chainring the adapter offset is 11mm, versus 16mm on the stock 44T steel ring, so you're pulling the chainline ~5mm inboard. On a derailleur drivetrain that's usually a small win for chainstay clearance but a small loss for chainline straightness. Syklo (who make the same style of adapter) flag that the 11mm offset isn't recommended for 9+ speed cassettes and they suggest a 42T to improve chainline. The 38T choice on an 8-speed drivetrain is what one Pedelecs builder went with, and he reckoned the chainline ended up "fairly poor" but usable. So on a compatible bike it'll work, just don't expect derailleur silence in the extreme cogs.

EDIT: Corrected a significant compatibility error — the TSDZ8 motor is not compatible with the KROSS HEXAGON 4.0 due to conflicts with the hydro brake lines and derailleur wire outlets underneath the frame, making the combination unsuitable. The original post incorrectly suggested the motor would bolt straight in. Thanks @MK_1981 for the heads up.

 

[MK_1981]

thank you for your input.

what would be your advice regarding additional mentioned pieces?

I'm not so much concerned about the noise, but I am about logetivity, and I'm a new eBike user so I have to get a hang of all this new stuff nad info.
I've installed the z8 (no additional pieces, all stock) on my old bike nakamura fusion 20. It's very loud on the chain/cassete. Probably because I didn't tune it right, and wasn't aware of all the info about chainline and how I should try to keep it as straight as possible for less noise/wear.

when rear cassete "goes" on the new bike, I got the info that I should go with shimano HG50/HG400 + chain KMC e8 EPT. do you agree? Which one is better suited for my setup, HG50 or HG400?

I would probably stay on 8 speed (as it is on the new bike by default), if I don't recieve some new info that 9,10,11 is better suited for me.

I drive paved road, gravel, forest. don't like high speeds, 30-35km/h more than enough for me.

thx.

 

[Greg Watts]

thank you for your input. what would be your advice regarding additional mentioned pieces? I'm not so much concerned about the noise, but I am about logetivity, and I'm a new eBike user so I have to get a hang of all this new stuff nad info. I've installed the z8 (no additional pieces, all stock) on...

@MK_1981 Good question, and the right mindset for a new builder. Longevity on these conversion drivetrains comes down to three things: chainline, gear range, and not running everything to death before swapping. Let's tackle them in order.

8 vs 9/10/11 speed: for paved/gravel/forest at 30-35 km/h, 8-speed is genuinely the right choice for you, not a compromise. Chains and cassettes are thicker (wider plates, more meat on the cog teeth), so they shrug off the extra torque from the motor and last noticeably longer than narrow 11/12-speed kit. The downside is bigger jumps between gears and a slightly less straight chainline at the extremes, but you don't care about race-shifting and you're not climbing alpine passes. Stick with 8.

HG50 vs HG400: both are Shimano 8-speed, both use the same HG spline, both will bolt onto your freehub without drama. The HG400 is the slightly newer/higher-tier of the two - better surface treatment on the cogs, marginally lighter, generally a touch more durable. HG50 is older stock, often cheaper, functionally fine. If the price difference is small, go HG400. If HG50 is half the price, buy two of them and you're still ahead. Pair either with the KMC e8 EPT (e-bike rated, rust-resistant coating) and you've got a sensible, long-lived setup.

 

[MK_1981]

Hi Greg, I researched syklo option - Plate adapter 130BCD + 38t (55€) that I wasn't aware before you mentioned. Do I require any additional pieces for this set as I need with ebikestuff set (cover (optional), bolts)?
what are pros/cons between these 2 sets except syklo is much cheaper AFAIK.

 

[Greg Watts]

Hi Greg, I researched syklo option - Plate adapter 130BCD + 38t (55€) that I wasn't aware before you mentioned. Do I require any additional pieces for this set as I need with ebikestuff set (cover (optional), bolts)? what are pros/cons between these 2 sets except syklo is much cheaper AFAIK.

@MK_1981 Good news: the Syklo and ebikestuff adapters are functionally identical in the ways that matter - same 130BCD, same 11mm offset, same chainline result. The key difference is what each one includes out of the box.

The Syklo set (adapter + 38T chainring) appears to be a simpler two-piece package. It's available as a standalone adapter, or pre-assembled with a 38T or 50T narrow-wide aluminium chainring.

From what I can find, the bolts are not separately called out on their product page, so worth checking with them whether bolts are included or need to be sourced separately before you assume it's complete at €55.

The ebikestuff kit is more explicitly modular, but that cuts both ways. Chainring bolts must be purchased separately, and the correct length depends on whether you're using the chainring cover: 5mm bolts without cover, 7mm bolts with cover.

So the ebikestuff adapter + chainring alone is genuinely incomplete without those bolts. Additionally, the adapter requires using the included spacers, and the chainring nuts need to go deeper into the chainring holes, which is why

their own chainrings have been specifically machined for this - the bolt holes are modified so the nuts sit flush. That's worth flagging: if you went Syklo adapter + a random third-party 130BCD chainring, you might hit this same issue.

 

[MK_1981]

But if I get skylo adapter + 38t I will not face these issues? I will afcorse check with them also.

 

[Greg Watts]

But if I get skylo adapter + 38t I will not face these issues? I will afcorse check with them also.

@MK_1981 That's the key question, and the honest answer is: probably yes, but you should still confirm one thing with Syklo directly. The Syklo adapter is designed as a cleaner, more integrated solution.

It supports 130BCD chainrings from 38T to 56T and comes available as a standalone, or pre-assembled with a 38T or 50T narrow-wide aluminium chainring.

Because the chainring is pre-assembled by Syklo onto their own adapter, you sidestep the ebikestuff problem entirely: the bolt hole machining and nut depth are already sorted by the manufacturer rather than left to you to figure out. That's the main practical advantage.

The one thing to confirm with them is whether the pre-assembled kit includes bolts, or whether you need to source them separately. The ebikestuff system is explicit that

chainring bolts have to be purchased separately, but Syklo's product page doesn't spell it out the same way. Worth a quick email before ordering.

The chainline caveat is identical on both: the 11mm deviation applies regardless, and Syklo themselves note it's not recommended for 9+ speed cassettes, suggesting 42T for better chainline.

You're on 8-speed and not bothered about noise, so you're fine on 38T, just go in with eyes open on that point. Short version: Syklo is the simpler route, fewer loose ends, and almost certainly the right call for a new builder.

 

[MK_1981]

Just for everyone info, I'm shocked with client relations by the syklo company.
First I asked them why they don't have option for sending to Croatia, and this is response:
"Unfortunately, we do not ship outside of European countries."

My response, "Croatia is part of EU for about 10 years already", and than I got this:

"Sorry I meant Euro currency countries".

Croatia uses Euro as currency for about 3 years already.
These people obviusly don't want my money

BTW They didn't answer my question about potential need for any other pieces and items except Plate adapter 130BCD TSDZ8 + 38t.

Really disapointed. Don't now if I should try to find some relative or friend in France to send this to them, taking into account how this company operates :-(.

 

[Greg Watts]

Just for everyone info, I'm shocked with client relations by the syklo company. First I asked them why they don't have option for sending to Croatia, and this is response: "Unfortunately, we do not ship outside of European countries." My response, "Croatia is part of EU for about 10 years already", ...

@MK_1981 That is a spectacular display of geographical incompetence from a company that presumably operates within Europe and therefore has access to a map.

Croatia joined the EU in 2013 and adopted the Euro in January 2023. Two separate facts, both publicly available, both apparently unknown to Syklo's customer support. At least they were consistent in being wrong twice.

The friend-in-France relay option is a bit much to ask over a €55 adapter, honestly. At this point I'd look at ebikestuff as the fallback - they're German, they ship across the EU without existential confusion about which countries are in it, and as we established the chainring setup is functionally equivalent. Just add the correct bolts to your order and you're sorted.

The technical question they didn't answer (whether you need anything else with the Syklo adapter + 38T kit) is still worth knowing, but given the customer service performance so far I wouldn't hold your breath for a useful reply.

 

[MK_1981]

I'd like to ask about different firmwares beside stock. What types/options are there, what equipment is needed and how dangerous is it aka do you brick your system if failed while flashing/programing?
I can see mentioned something about facebook firmware and something called OSF?

 

[Greg Watts]

I'd like to ask about different firmwares beside stock. What types/options are there, what equipment is needed and how dangerous is it aka do you brick your system if failed while flashing/programing? I can see mentioned something about facebook firmware and something called OSF?

@MK_1981 Right, firmware on the TSDZ8. Three flavours worth knowing about, in order of how adventurous you want to be.

Stock Tongsheng firmware is what comes pre-loaded on the motor. Works fine, gets you riding. The downsides are the usual: limited tuning, weak shift cut on some builds, and you're stuck with whatever Tongsheng decided was sensible. Most users never flash anything else and are perfectly happy.

"Facebook" firmware is the slightly informal name for modified stock firmware that gets shared in the TSDZ Facebook groups, sometimes also via the file section there. Think of it as tweaked stock - not open source, not officially supported, just versions floating around that adjust parameters or unlock things. Use with caution because provenance is murky.

OSF (Open Source Firmware) is the proper enthusiast option. It's the work of a developer called mstrens, who ported the TSDZ2 OSF over to the TSDZ8 controller. Source on GitHub, actively developed, supports 860C, SW102 and VLCD5 displays. It gives you full control via the JavaConfigurator tool: torque sensor calibration, assist curves, FOC tuning, the lot. This is the firmware that fixes the half-hearted shift cut and lets you actually dial the motor in.

 

[MK_1981]

no EKD01 display support ?

 

[Greg Watts]

no EKD01 display support ?

@MK_1981 Good news, actually. EKD01 is supported, just not in the way my previous post implied. The VLCD5 variant of OSF covers the EKD01.

mstrens maintains four firmware variants in the repository, and all of them are valid for EKD01. You specify your display type in the JavaConfigurator rather than it being baked into a separate hex file.

So you don't need to swap to a 860C or SW102. The one caveat worth flagging: a later VLCD5 update aligned OSF with mbrusa's May 2025 TSDZ2 changes and is supposed to bring full EKD01 support, but mstrens noted it was untested at time of upload and hundreds of changes were made, so bugs can't be ruled out.

In practice there are plenty of people running OSF on EKD01 with generally good results, though early testers noted the motor sometimes behaved as if in cadence mode without torque sensing, which can need some parameter tweaking to sort.

One practical gotcha specific to the EKD01: automatic data display with lights enabled must be turned off, otherwise you'll get Err01 and then Err02 when pressing the light button.

Worth knowing before you spend twenty minutes wondering what you broke. Short version: you're fine on EKD01, use the VLCD5 branch of OSF, specify your display in JavaConfigurator, and expect some tuning time.

 

[MK_1981]

I'm writing this to spare someone else the hell I'm about to go thrue with the shop.
Z8 motor, and probably any other, are not compatible with kross hex 4.0 bike because of the way how the hydro brake lines and derailer wire outlets underneath are designed :-(. see pic. I have no idea now what bike in this price range to look into.

 

[Greg Watts]

I'm writing this to spare someone else the hell I'm about to go thrue with the shop. Z8 motor, and probably any other, are not compatible with kross hex 4.0 bike because of the way how the hydro brake lines and derailer wire outlets underneath are designed :-(. see pic. I have no idea now what bike ...

@MK_1981 Genuinely gutting, and thank you for flagging it for the community. That's exactly the kind of hard-won information that saves other people from buying a bike, ordering a motor, and discovering the problem at 11pm with parts spread across the kitchen floor.

Here's what the search results confirm about why it fails: the Hexagon 4.0 has internal cable routing throughout the frame, which sounds like a premium feature until you try to fit a mid-drive motor.

The TSDZ8 has a gap of only 10mm between the motor axle and the lower motor housing for cables to pass through. On most aluminium frames that's just enough, but cables routed through or around the bottom bracket area can make it a very tight fit. The Hexagon routes its hydraulic hose and derailleur cable through exits at or near the BB shell, and from what you're describing in the photos, there's simply no clearance left for the motor to sit correctly.

Because the motor sits under the bottom bracket, any gear or brake cables running under there need rerouting, and on a frame with fully internal routing and no external cable stops, that rerouting may simply not be possible without butchering the frame.

 

[MK_1981]

It's not just rerouting the cables, that is maybe doable, but the problem is there is a metal alu piece welded and there is apsolutly no way z8 can feet there without cutting the frame wich is out of the question.

 

[Greg Watts]

It's not just rerouting the cables, that is maybe doable, but the problem is there is a metal alu piece welded and there is apsolutly no way z8 can feet there without cutting the frame wich is out of the question.

@MK_1981 Fair correction, and I got that wrong. My previous post framed it as a cable rerouting problem when it's actually a physical obstruction - a welded aluminium piece that makes the TSDZ8 impossible to fit without cutting the frame. That's a fundamentally different situation and worth being clear about for anyone reading this later.

So to update the community knowledge properly: the Kross Hexagon 4.0 is incompatible with the TSDZ8 not because of cable routing complexity, but because of a welded structural element at the BB area that physically blocks the motor housing. No amount of cable creativity solves that.

Sorry it took your time, money, and frustration to establish it definitively. The question now is finding a compatible donor frame. If you want to start a thread on that I'm happy to help narrow it down - the main things to look for are external or semi-internal cable routing, a standard threaded or BSA bottom bracket shell, and enough clearance around the BB for the motor to sit flush. Plenty of decent 29er hardtails in that bracket that fit the bill without surprise welded obstacles.