Board engages brakes out of nowhere

So i just had a fun first day of the year, riding home from new years celebration i was going around 50 kph when suddenly the board started to brake drasticly. needless to say i got thrown of and did a couple of barrel rolls on the asphalt, it was a hard crash, thankfully i had the Lazyrolling armored jacket and my ruroc helmet on and i could walk away with minor damage. The remote was turned off when i got back up and i thought that the board braked due to lost connection, i want to remember that i’ve read about this before. when testing this on the bench (turning off the remote at maximum RPM) it just freerolls down to a stop though.

So after inspecting my board everything seems fine on it. i got no fault notifications in the METR app, the board did not shut off, it was still turned on and worked after the crash, motors spin normally. according to my Xiaoxiang BMS all cells are at 4.03-4.05V.

Info about my electronics
12s9p 30Q pack at roughly 48.5V
2x Trampa VESC 6
2x APS 80100 motors
BMS Bypassed for discharge

This spooks me out a lot, not being able to trust in my board. Anyone experienced this aswell? i would love to hear ideas of why this occured.



A 50km/h crash can end up very bad. Glad you are ok.

Upload the metr log, that way you can also check the ppm signal.
In any case, loss of power feels like braking especially under acceleration.


Can confirm. It does feel like brakes when connection is lost for a split second even.

What remote are you running?


Did the remote turn back on when you got back up? Is it a momentary switch or a position switch out of curiosity


@taz thank’s mate.

I uploaded the log, i get some more specific information but can’t find anything about PPM signal in there. it sounds logical that a loss of power would feel like braking, especially since i got quite some rolling resistance with the 80100 motors. Although as seen on the second picture it does actually show -27.7A and -41.9 motor A.

@Dareno I’m using the APS remote

Been using it for about 9 months and never had an issue with it untill now, that is to say if the remote did turn off before the crash or after hitting the tarmac. Remote seems fine though, just some small scratches.

@Venom121212 it does have both a position switch and a momentary switch

Switch on the PPM graph shown here. That way you can check what happened to the signal.


Good to hear you ok!

Did you check battery level of the remote?
Maybe it was on the edge to be empty.
I had issues with that remote as I always forgot to fully switch it if and it drained the battery super fast :sweat_smile:


@taz hmm that’s funny, i do not get the PPM tab, app last updated december 27th


Haha yeah i know what you mean, when i first got the remote i never understood why the battery was always dead. Now i always switch of the position switch though, i charged it yesterday and after that i’ve been riding for only 30-40 minutes untill this happened. The remote has now been turned on next to me for 2 hours and it is still powered on.


In that case you must have the old metr module not the pro, correct?

It is the Metr pro, although maybe not the newest model. not sure just how old it is since it was previously used in a bioboard prototype and i installed it in my trampa this summer

Weird. Paging @rpasichnyk

Edit: Have you also updated the module firmware?

that might be why, i have not done anything with the module itself.

In that case, you need to update the module firmware.
Unfortunately this means we have no way of looking at the ppm signal during your fall.

yeah that’s a bummer, i would really like to see if it switched off before or after the crash

This is really freaking me out since I bought trampa vesc 6 based on the hat very few problems occur with them

Where do you think the problem lay in? In the battery, bms, vesc, remote etc…?

Same here, never experianced or heard about any problems at all with the vesc 6’s.

  • The problem is definitely not the BMS since its bypassed for discharge.
  • Battery was at 48.5V and all cells are balanced so I can’t imagine it’s the battery
  • Motors seems fine, and roll smoothly which indicates it’s not a short circuit.
  • shouldnt be the remote, even if it turned itself off before my crash that shouldn’t make the board brake.
  • no errors in the log data

Honestly have no idea, I haven’t opened the vesc case up and had a proper look at them. On the bench the whole system works fine but maybe it will be difference once I put some load to it on the street, for now I need to recover a couple of days before I do real world testing


I think it would threw an abs overcurrent fault which you didn’t had, but might be a broken solder join or the phase wires from the 80100 motors which broke due to vibration.
Just one of a lot of options.
Strange that you didn’t got any fault code.

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Is there any way to get this other than via control signal (ppm)? if the motor itself locked up, maybe?

Otherwise gotta take a hard look at the ppm signal chain. Solder joints, connectors, failsafe, etc.


Definitely going to do a proper inspection of all wiring and the motors themself. Maybe you remember when we talked about my old 8085 motors that got short circuit due to phase wire insulation that melted inside of the motor. That also made the board brake of course but not like this.

The damn negative current is the thing that haunts me, I don’t see how that happened. A mechanical error, short circuit, loss of signal or loose solder joint shouldn’t make the board hit the brakes right

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I don’t see how locked motors should send negative current though, indeed I will go over everything