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.
(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