Noticed today after a 10km ride my 6485 138Kv motors are pretty hot to the touch, shouldn’t the milled radial vents and the mesh suck air through to keep them cool? I’m running 15A per motor on 18s with a 5:1 ratio in 8" tires.
Can I do something to keep them from overheating this summer? Besides only riding on cold days?
What were the temps?
Voyage tells me 47-48 degrees but they felt closer to 60 or 70
I know Reacher datasheet says they can handle up to 100C but this being my first motors with cooling, I kinda thought they’d run cooler.
I’m used to flipskys being this hot when I ride but I figured these wouldn’t be so hot.
Maybe I’m just freaking out over nothing.
Here’s the ride: May 30, 2025 - metr.at | 16akO
Did you adjust the beta value to 3950k?
Sorry ya lost me there… In vesctool? I usually don’t touch temp sensor stuff.
Yes, thermister will give the wrong temperature value if the beta value isn’t correct. The default thermister value in vesc tool doesnt match the correct beta value for reachers.
@janpom is there a way to apply this thermal modification to previously uploaded Voyage records? I never realized I had this value wrong the entire time.
Seems like it’s sorted. They definitely felt like 55 degrees after this ride.
Poke two holes in a bottle of water and hold it behind you.
Hilarious but I bet that would actually work lol
It can. I had a system with wet rags for cooling when i would go overtemp and have to stop.
55C is nothing haha. As they get hotter the cooling fan becomes more efficient. Usually pretty quick to get to 50-60 and a lot slower to get to 85+
Having acceleration temperature decrease settings at 100/115C helps you get to 100C without early throttling
So I shouldn’t have to worry too much about ambient heat then? It’ll get up to 45C some days in the summer here
Cooling efficiency increases with temperature difference. But electrical resistance and losses also increase with heat so they do get hot with hotter ambient temps.
Just keep an eye on temps and if you’re getting thermal throttle before the motors reach 95-100C you need to tweak settings to ensure you’re not leaving performance on the table.
Not sure if you can modify the records in the voyage cloud, but if you wanted to know the temperatures, the math is pretty easy.
multiply the temperature by the old beta value, then divide by the new beta value
Which setting would one tweak?
Motor temp cutoff start and end, and some people like acceleration temperature decrease below the default 15% although it works fine for me.
