Constantly overheating motors in dual setup

Hi there,

I would need some expert advice from you guys and I hope somebody of you can help me out:

I have a dual-rear setup using:

2x 6374 Maytech Motors 190kv closed can, sensored in FOC

15:36 gearing ratio

2x Vesc 6 with latest fw connected by canbus

10s4p (Samsung 30Q)

90mm Popoca wheels

Problem: my motors keep on getting too hot. After 20min of riding on flats (about 25 Degrees C ambient temperature and I weigh about 72kg), both of my motors reach 72-85 degrees C. What am I doing wrong here? The braking is perfect for me as it is right now, but do you guys see any way of reducing the motor temperature to more acceptable levels without changing the gearing ratio? My belts are not too tight nor too loose. This overheating issue also occurs with other motors like the SK3, sensored and non sensored.

Settings on Vescs are default with only the below settings changed:

Vesc Master:

Motor Type: FOC

Sensor Mode: Sensored

Motor Current Max: 67

Motor Current Max Brake: -50

Battery Current Max: 27

Battery Current Max Regen: -8

Vesc Slave:

Motor Type: FOC

Sensor Mode: Sensored

Motor Current Max: 67

Motor Current Max Brake: -50

Battery Current Max: 27

Battery Current Max Regen: -8

thank so much for your help

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mmh maybe you have broken windings? did you check the stator for dmg?

Original sk3’s don’t have sensors, meaning vesc can’t even detect overheating and throttle down the motors.

Also how are you reading motor temps?

hi Alan.
i mean i tried sensored and non sensored motors…among which is the sk3…
the motor temps i am reading from the metr. app…i am just wondering why my motors are always so hot that you cannot touch them for a long time, whereas i read that others on the forum only have temperatures of 50-60 degrees.
is there any way to reduce motor heat via the settings on the vesc tool? acceleration is perfect as well as braking…

Your settings are normal, we’re you stopping and starting a lot on when riding flats?

stopping perhaps every 15-20min to check if everything is ok. i also did not go crazy high speeds, perhaps 30-35km/h at the most.

Lower the motor current max?


shouldn’t be a problem. i don’t get hot motors even going up hills with 40km/h and i am heavier. I still think there is something wrong with the motors.

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To check your motors by hand is a simple process.

Disconnect from the vesc. then follow these simple steps
Let’s say the phase wires on the motor are A, B, and C

Touch A+B together. Verify the motor has choppy brakes
Touch A+C together. Verify the motor has choppy brakes
Touch B+C together. Verify the motor has choppy brakes
Touch A+B+C together. Verify the motor has SMOOTH brakes that are much stronger

All the choppy brakes should feel the same. If one is weaker or stronger or if anything isn’t as described above, it means you might have winding issues.

You should not be getting those heat readings on those settings so either there is a problem with your motors or theres a problem with the read out on your metr app. Have you tried touching the motors when they give these readings?

Welcome to the forum btw


@Kingdom421: already tried all of that, but still i always reach motor over temp faults. it is definitely not the motor (maytech 190kv closed can that i am currently riding), because the others are the same.

could it possibly be an issue with the Vesc 6? surprisingly, the Vesc 6 remains just slightly warm…not hot at all.

@Dareno thanks for the suggestion. tried all of that as this was already suggested in the builder forum…all motors seem to be all good.

if anybody else has an idea, please help, thx a lot in advance

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Have you checked the motors with a temp gun? Are the motors throttling when hot? Losing power?

@Dareno have not tried using a temp gun and the motors are not throttling at all and also not losing power. there is still plenty of headroom left for further acceleration.
i am going to try out a flipsky dual esc to see if it could be the VESC 6.

Edit: even if i cannot actually measure the temp apart from the metr app, the motor is too hot to touch.

Thats what I was trying to get at. Actual data and not metr. Very unlikely the vesc 6 is causing this but lets ask the man @trampa
Frank have you ever heard of the vesc 6 causing hot motors?
Settings look good. Weird one.

I’m thinking maybe riding style and environment. Or I am missing something obvious.

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Are you sure you’re looking at motor temps or esc temps?

Hi Matt. Definitely these are the motor temps. VECSC 6 is mildy warm…whereas the motors (both) are too hot to touch for a long time. i always reach motor over temp. fault

Doesn’t sound right at all. I have the same motors but open kind and they never reach those temps. They stick around 45-50C when I push them hard.

My settings with escapes.

Oh i thought you checked the motor temp IRL not just the data given by the Vesc. If you can safely touch them after getting a temp fault then you have your answer. Sensor itself could be damaged or something else.

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What could help maybe is: applying thermal paste between motor and mount to help transfer the heat better

And add heatsinks on the trucks ofc.

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What I have found makes a huge difference in motor temperatures are (apart from ambient temperatures) inclines and average currents.
I have constant overheating problems when it starts to get warm.
I also average 45A motor current (22.5A per motor) and sometimes a lot more.

Here is a typical trip, this one is downhill most of the time. When I do the same route the other way, it is mostly uphill. I have to stop to let the motors and focboxes cool down.

On my Trampa the VESC6 are a lot cooler but it is the motors that overheat.

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