1 Like
Special thanx to Maxime from France to share some pics on the insides of the new SBX2. 
He used it on wet pavement near the forest and the casters were not spinning nicely anymore so he had to clean them.
When he got the board new, the bearings looked dry… I think they need to be greased up regulary when using them in wet conditions.
4 Likes
saw this on fb marketplace, how much should I low ball him lol ?
1 Like
Old SBX1… hmmm… 600?
I bought mine for 500 with working electronics, but then both the BMS and the ESC decided to stop working.
Definitely be ready for a diy project, fitting a new battery and potentially a new ESC and remote. Might be simplest to just use a pelican case for that.
5 Likes
1 Like
Jerky acceleration with Traction Control on DIY e-freeboard
I’ve been trying to get traction control working smoothly on my dual VESC setup, but I still can’t get rid of the jerky acceleration behavior.
Setup:
- I have tested 2 complete sets; MakerX D100 14s2p P45B molicell and a Stormcore 60D 12s2p molicell P45A
- FOC mode
- Sensorless, HFI, VSS
- 2x hoyt puck, PPM input
- Motors: 2x Flipsky 5065 200KV and 2x Reachers 6365 205KV
Issue:
When traction control (TC) is enabled, the board accelerates with short surges or jerks — especially at low speed or whenever there’s a slight traction difference between wheels.
With TC disabled, everything runs perfectly smooth, but then I obviously get wheelspin when pulling a manual or at slip moments.
I put it in a table, this is me doing 6 figure eights on my driveway. (I somehow only get data of one side of the controller, think you guys get the idea 
)
What I’ve already tried:
- Tested various Traction Control Max ERPM Difference values (from 500 → 6000 ERPM)
- Motor current limits (25A - 75A)
- Rampup times (0.2-2 s)
- Combined TC with a lower Duty Cycle Current Limit Start to soften torque peaks
It feels like the current TC logic in the VESC firmware is a simple on/off reaction based on ERPM difference, rather than a proportional torque correction. I think that’s what causes the surging under acceleration.
Question:
Has anyone managed to make TC behave more smoothly, where torque is reduced proportionally rather than clamped instantly?
Any ideas or code-level hints are welcome — I’d also be willing to test a custom add-on or patch if someone has something available?
2 Likes
Traction control on vesc matches all motors to the speed of the slowest turning motor… it’s super lame.
4 Likes
I often wonder what Aaron from Summerboard is eluding to when he says the SBX uses the Gyroscope IMU for traction control somehow. Surely there is some cool effect you could harness from responding to movement direction.
2 Likes
Yeah that’s a good one … it could actually add something to a e-freeboard. The outer wheel should be able to spin a bit faster when initiating a turn. If the IMU detects that you’re turning or leaning, it could allow a bigger speed difference between the two motors without traction control cutting in too hard.
1 Like
I’m riding only 10S voltage right now. So I hit the duty limits when riding often. I’m telling myself its good practice and for testing software issues that could be touched upon for riding vesc sbx near max duty cycle. Right now I need to order fresh sets of sealed bearings, and weatherproof a board to the max. Perhaps finally properly tpu gasket the sbx1 slip ring, I think I would need something like that center wheel fender to get anywhere with riding in the rain, edge wheel fenders too come to think about it.
1 Like
I’ve designed a smaller setup for 60–90 mm wheels that’s pretty much waterproof.
The only reason it isn’t made in metal yet is that I’m still testing the larger version and figuring out what needs improvement.
Are you also running it in FOC?
1 Like
Using a very cheap dual 4.12 esc, Thought it was bldc for a moment but yeah FOC.
Pretty sure I should be be more precise with the Motor amps to Batt amps to ABS Amp limit. There is a formula somewhere. Batt(14A-4A) is super chill I like not worrying about tearing belts or throwing myself off with a whisky throttle.
1 Like
So your board rides floaty and chill. Do you ever run into the same issues I’m having with my setups? (I’m assuming you have TC enabled and are using the default 3000 ERPM diff value.)
1 Like
Honestly this doesn’t really ring a bell. but I will test and look for this asap for you.
hmm wonder why I made it so low. Maybe it was spinning up the front wheel too much in a press.
1 Like
Much appreciated! 
1 Like
That doesn’t sound crazy at all… I had it most time set at 1200, preventing spin when pressing/doing a manual.
Wheels, board & TC shizz..
Looks like the TC fix will have to wait a bit longer. Since I’m not really a programmer (and this stuff is already challenging enough for me), I figured the best I can do for now is make a pull request for VESC instead of trying to hack things together myself.
In the meantime, I went back to what I actually enjoy, building hardware. 
I’ve designed and printed a new 90 mm fully round-profile center wheel with internal suspension holes. The core is PET-CF, which has proven super durable on my other drive setups. I’ve tested several shapes before, and this one performs best. I’m now looking for a good 2 component epoxy to glue te core and tire together.
Also worked on a new board design for a 85W progressive concave that I want to make in 7 ply woodcore with a carbon layup.
The tires are printed in Polyflex TPU 90A, with 5 wall loops, gyroid 90% infill. The goal is to end up with a wheel that feels a little softer than 80A.
Happy to share STL/STEP/3mf files if anyone’s interested.
Alright sorry we had a week straight of rain. I’ve done two good rides looking for any jerky behavior on acceleration. all seems smooth to me, even with very neglected slip rings. I think if its not my low Amp limits it might be that I am running V4 vesc hardware/FW. idk man maybe we need to compare CSV logs?
Maybe these will help us compare our data:
or even more fancy with videos
2 Likes