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As a keen Ebike builder and modifier I am always looking at other options available for powering the wide range of Magnificent machines we have here at Empowered People, but also I’m mindful of future projects and adaptations that may be required.
I’m keen on understanding what options there are in the DIY market for converting standard bikes to e-bikes. Historically this was always done with wheel hub motor systems, where you swap out the front or rear wheel with a hub motor, This is generally an easy process but has some disadvantages over other drive methods such as mid ‘Crank’ drive motors. The main disadvantage being low torque at low speeds which is a real problem for hill climbing.
In this post, I want to introduce a new mid drive system I have recently acquired to experiment with, the TongSheng Tsdz2
So why the Tsdz2?
I first heard about this mid drive motor by coming across a YouTube review on it. One of the main things that interested me was the fact it used an internal Torque sensor to detect the amount of effort the rider was putting into the pedals and using this to constantly change the additional power provided by the motor. This works in a very similar way to the Bosch drive systems. But unlike the Bosch, the Thonseng can be retrofitted to any standard bike frame with a standard bottom bracket.
I soon discovered that there was also an awsome open source project to replace the stock firmware with a much more advanced and highly customisable version, as a keen electronics hacker my ears pricked up on this. And soon I was reading up on how mature this project had already got to, and so I kept an eye out of r a second-hand unit to play with.
Low and behold a few weeks later and I find one on eBay for a very reasonable price with next to no use. So the tinkering begins.
To start with I wanted to try the motor on a standard Mountain bike in ‘stock’ form using a spare 36V battery (this is the 36v version of the kit).
So off comes the standard Bottom bracket.
And in goes the motor
What’s nice about this motor, is its small size. Sure you can spot it, but from the drive side it’s almost hidden
Other than being a bit big the original screen works fine in stock form but can not be easily used with the open source firmware I plan to try.
So how does it ride in stock form?
Well, my kit was the 36v 500W version and yes it definitely had plenty of pull when needed. Most of the time in ‘tour’ mode it would pull around 8A and felt very similar to all 250W wheel kits I am used to but switch to ‘sport’ mode and I was seeing up to 16A draw on the battery which was plenty powerfully for hill climbing peaking at around 550W! Quite a drain on the battery!
This is where the open source forward can help out. Not only does it unlock the motor to use any battery from 24v -52V but it also uses some clever tricks in how it controls the motor to make it more efficient and require less power to get the same output.
So I ordered a new KT-LCD3 screen which is required as it can be programmed to work with the new firmware. And went about reflashing both the motor and the screen when it arrived.
So what does the new firmware feel like and was it all worth it?
Well I can say right off the bat the new firmware when set to 500w the motor is only drawing about 10A to get the same power output but not only that it’s quieter, runs smoother and has a great boost feature that gets you going with a boost of power then automatically drops back once your on the move.
But that’s not the end of it, as I can use other higher voltage batteries I decided why not try a 48V battery. My thought is that the higher voltage would allow for lower amps to achieve the same power, and boy what a difference!
Now I am averaging only 5-7A. To get a nice general assist and have plenty of power at my fingertips to attack the big hills in off-road mode.
I am excited to try this motor with the open source firmware on a range of adapted bikes as it extremely flexible. For the empowered riders it’s very easy to use you an simple pedal harder and your work is amplified. And occasionally change assist level if you come up to a big hill.
For me I love the ability I have to fine tune the power in each mode. The flexibility to use a wide range of existing batteries we already have from 26v to 48v but also it opens up options for some of the old e-trikes and recumbent hand trikes that were always limited on the power options we could add.
I am looking forward too seeing where we can use the tszd2 in the future.
But for now. I am having a lot of fun testing it on my On-one inbred mountain bike
I did find the battery mount was only being supported by the two bottle mount holes. So I decided to design and 3D print some extra support to add stability and spread the lead. So far these are working great and there is no movement in the battery.
UPDATE: For anyone interested I have uploaded the 3D files for these here
(on this frame a spacer was needed to clear the chainstay)
I will update on this project as I test out new features of the open source firmware and see how we can make best use of the TSDZ2 on our next magnificent Machines.
New Beta brings new features in Part 2
Empowered People 
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Thanks Neil for sharing this. We love the TSDZ2. We have 2 off them on our hard tail bikes. Boardman and Kona.
I have a third one 250w 24v which was going cheap on eBay. Can I use a 36v battery with this using the existing controller/firmware or do I need to upgrade
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Hi Chris. It’s my understanding that there are actually only two differnt types of TSDZ2 motors, 36v and 48v.They both use the same controller but use different Firmware. One of the settings in the firmware is the maximum battery voltage expected and the firmware will not enable the motor over this. When I first tested my 36v motor it came as 36v and worked great on a 36v battery but would not run on a 48v battery. However I did reflash to the stock 48v firmware and this did work. I am sure you can flash your 24v motor to stock 36v as they are physically identical and it’s just the battery settings in the firmware that differs.
You can get original Firmware and instructions to how to flash it here..
https://www.eco-ebike.com/blogs/eco-cycles-instructionals/tsdz2programmingfromscratch
Alternatively if you would like to you can run the custom opensource firmware likeine and run at any battery voltage from 24v-56v with a simple setting change via the screen menus. I didn’t go into the details in the post but there is also a build of the firmware that can use the existing VLCD5 display.
More info on that here
https://endless-sphere.com/forums/viewtopic.php?f=30&t=98281
Personally I prefer the flexibility of the new screen so use the main open source firmware , but that does require some more work to setup a cable etc.
I hope that helps.
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Hi, and thanks for the post. I’ve got two of this units running well on 36 v. The first one was mounted in a mondraker curve bike and the only problem I still have is the alignment with the center of the rear cassette. Almost imposible so very difficult to use the whole range of gears. Then on the other bike (a 24 inches MTb bike for my daughter) I have a problem with the torque sensor I would like to get some help about. Is it possible to modify the sensing settings for the torque sensor? My daughter is barely capable of pushing with the miminun torque needed for the motor to start assisting, so even in the highest assist mode it’s not enough sensitive for her. In other words, I would need the motor assisting with less pressure applied to the pedals. Any idea how to get this apart from lengthening the pedal cranks (which I can’t as already too long for a 24 inches bike)? Thanks in advance.
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Hi Antonio,
Getting the optimum chain line is tricky on the mid drive motors, with the Tongsheng, I purchased the red offset chain ring which brings the chainline almost back to a stock large chainring. This enabled me to get all the gears on my 9 speed cassette. I did find that it was very dependent on the frame as to how close the motor would fit as it could foul the chain stays easily on some frames, you can put in a spacer but then you are making the chain line worse.
As far as configuring the torque sensor, this is very configurable when using the open source firmware. as you can define the multiplier for each assist level. so in effect you can get high power at low torque. One thing I did notice with both the stock firmware and the open source firmware is that on start up the torque sensor calibrates. so you must not step on the pedals while this happens or you will find you need to add extra pressure to get the torque sensor to read anything. This can happen easily. I therefore recommend people get on the bike (feet on the floor) then turn on, wait 5 seconds then put feet on the pedals and begin riding.
Have you tried using a throttle to get her moving? that will tell you if the motor has enough power to give her the assistance. But i’m surprised she cannot get it to trigger the torque sensor from a standstill (unless its what I described above)?
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Hi, Neil. Thank you for your reply. Much useful and appreciated. First, I’m glad knowing about the existence of the off set chain wheel although it wouldn’t help me as I had to adapt a 36 teeth sprocket to my double suspension mtb bike to cope with the very steep hills I have to climb before the party starts. I first tried the 42 which was far to high, then I went to adapt a 38 which improved the climbing capabilities a lot, and then I managed to fit a 36 which makes the chain almost touch the plastic cover of the motor itself. So I couldn’t go to the 34 I would have like it. Then I moved to the rear and found a 11/42 cassette which I had to modify so I moved it outwards to cope with the maximum dis alignment. So end it up with a usable 13/42. After that the bike was almost perfect for me but needed a bit more reduction so found a 11/46 cassette that I thought it would have resolved the problems out. But it didn’t. I fitted it the same way as the 42, so losing the smallest sprocket (actually I put it in the inner part of the cassette hub to use it as a spacer) but then I found that the so high torque created with the combination of the 36/46 plus the misalignment tended to bend the 46 sprocket, so it did. Next in my findings was trying to lose another smaller sprocket and move the whole cassette one slot more, and that worked but the trade off of having only a 20 teeth as a smallest sprocket, so not letting me get any sort of speed in the soft down hills. Finallly I went back to the 13/42 even thought I can’t approach the steepest hills.
Sorry if the story is too messy, just want to give some info back as per the one received.
Then for the problem with my daughter’s motor , yes I know about the calibrating system of the torque sensor as I suffered myself first with the mtb bike not understanding the changes in behaviour until I figure out the problem. It’s not hers. She knows it. But you gave me another great idea that was always there but so obvious that I overlooked it; the throttle. That will solve the problems as it won’t be long till she is able to go for a longer runs or get a bit stronger. Now the question is how to get one as I remember the have to be connected to an splitter that goes also to the speed sensor or something like that. I thing that splitter came with the kit but not the throttle. I’ll investigate it but it’s and easy solution for me.
Thanks again for listening and helping. Hope my little troubles can also help others.
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Hi, Neil . Hope this message reaches you ok. I have a Tongsheng tsdz2 250w fitted to my bike and I’ve only covered about 350 (dry) miles with it. It has mainly been trouble free up until a few weeks ago when it started to lose power after I’ve done a mile or so . Now the best way I can describe it is, it’s as if the power assistance is being slowly turned down as your pedaling and I found the only way I can get it back on track again is to stop turn it off and start it up again ,it will then be fine for a short time but then the same problem keeps recurring? I must also state that I have only ever used it in (turbo) mode as I fine all the lower modes make the bike harder to pedal than if it there were no motor fitted ? I have found it impossible so far to find any answers on the Webb to this problem ? Regards David
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Hi David. This sounds like the torque sensor is changing calibration. Typically this happens when you reset the unit while stepping on a pedal. So you in effectively setting the zero point to a positive value. But I have seen the torque sensor screw ( buried right in the middle of the axel) become slightly loose and the calibration becomes out of whack. I changed the whole torque sensor in one unit and manually recalibrated the middle point in the sensor to give a better reading at rest. The OSF version is helpful here with a large screen as you can read values live to see what it’s doing.
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Hello and good job!!!
Can you link or post your stl or similar 3D files for those marvellous 3D print extra support for batteries? Those are awesome! Thank you!!
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Hi VirtualBoy, Sure I was meaning to do that. I have uploaded the stl files onto Thingiversre here https://www.thingiverse.com/thing:3686417 please note they fit my steel One-on frame perfectly but might not be the exact right size for other frames.
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Thank you so much!
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I have amountailn bike with underslung rear caliper brakes will this create a problem when fitting the motor
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Hi Bill,
It will likely make it impossible to fit the rear motor mount that stops it rotating. Also I have had issues with clearance between the bottom bracket and where the motor sits. You only have about 4mm max. So even rear gear cable routing that goes under the bottom bracket can be an issue when they use a plastic guide. So I’m afraid you may find that frame isn’t suitable.
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Hi Neil,
Great article! Thanks so much for the STL files. I’m assuming that your prints were printed solid with ABS or did you get away with some other configuration?
I have been using my tongsheng for my daily commute and it has been great. One thing I had to modify was to change my bike to disk brakes from v brakes. The v brakes would always wear through! After the upgrade it has been great.
Cheers,
Tim
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Hi Tim, No I actually printed them in PLA at about 40% fill I think. I have found that they have stood up very well so far to the weather and some sun and no layer cracking as yet. I have actually made a second set for a colleague and those are standing up equally as well. You could indeed print in ABS or PETG if you prefer. And yes good disk brakes is a must for the TSDZ2 for sure! if you are using the standard firmware for the TSDZ2 I would suggest you take a look at the custom firmware options now avaliable, this really does make the drive so much better. but does require a bit of hackery display wise. https://github.com/OpenSource-EBike-firmware/TSDZ2_wiki/wiki
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Cool, I’ll check it out.
For other people that are thinking about getting this motor:
– On my bike I had to grind out a lip in the bottom bracket to make the motor fit. I used a Dremel with ceramic disk (it is an aluminium bike). After that it was all good.
– Waterproofing was something I didn’t think about from the outset (it is pretty dry in Sydney). I ended up using ziplock bags around the display, self sealing silicone tape and dilectric grease around the connectors. I’m not quite sure what to do about the battery and generally just use a plastic bag when it is raining.
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Hi Neil, I’m looking to build an ebike with either mid drive or electric front wheel. My thoughts are go mid drive but I have weak fingers and cant operate the brakes so I fitted a rear coaster wheel (shimano Nexus 7). This setup is working well but I have weak legs also due to slow GBS recovery. I’m wondering if a mid drive motor is compatible with a reverse pedal hub brake system. Does the TSDZ2 switch off power when back pedalling ? What’s your thoughts on which route to take mid drive or front electric wheel. Thanks in advance.
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Hi Toni. There is a specific Coaster brake version of the TSDZ2 motor that does not have the sprag clutch. This allows you to back pedal to activate the rear coaster brake as you currently do. I would recommend this over a front wheel motor if you can to ride hills. Front wheel motors work well on flatter road rides. But struggle on Hiller terrain as it’s difficult to get the same power at lower speeds. A mid drive really helps as you can choose the gear that best suites. Have a look here for the TSDZ2 (coaster brake) http://www.pswpower.com/ven.php?cargo.2018-8z-qcpg
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Good info. I’ve been there. https://www.youtube.com/watch?v=Bf9uWBCPZvQ
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Tongsheng is a new motor for me to try with the default software. I had a Bewo before and it used cadence sensor not torque. Different to ride and no info if it failed… but it got stolen.
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I have the original display. https://empoweredppl.files.wordpress.com/2019/01/s-l300-29088776496439625738.jpg and it has usb which I thought for charging devices but seen the display can be used for reflashing.
I got usb to ttl converter and use micro controllers but reflashing this display seems to use more unknown software.
Do we have to change the display and is it going to make my 350W 36V tz 42tooth 9 speed shimano go better?
regards, stan
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Hi Neil
Have you had any experience with the TSDZ2B motor system? It looks to have better internals and sprag clutch, I’d like to hear your thoughts or experience.
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I have installed the TSDZ2B on two bikes now. One was a regular mountain bike, the other was a low down recumbent trike. Both are working well. Both appear quieter than the TSDZ2 , and the stock firmware is smoother than stock on the TSDZ2. It’s frustrating that you cannot currently use open source firmware on them. But to be fair out of the box they are good. Personally I don’t think the second clutch is very noticeable, it’s not as free running as a boshe drive, but I have heard that this is a bit hit and miss and some are much ‘looser’.
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