LAVAGIRL - tomiboi MTB | ubox v1 | 12s8p p42a | Luna 350s | Reacher 6485s

Roger that, but I was noticing they felt hot to the touch… will have to check specific temp values once my Robo is up and running.

Although checking in the freesk8 app rn, the motors and ESC both say they’re at 70°/room temp which should be accurate

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My reachers are also hot the touch after a few fast miles (130 motor amps, 70 battery) but not hot enough to cause concern. I got my cutoff start temp set to 100c, and they are getting nowhere near that as of now. Maybe like 55c.

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How does the thermistor beta value impact motor temperature? It only changes the temp reading on the log, correct?

Hot reachers seem to be a reacher thing per some digging on the forum, so not sure there’s a solution to it.

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Ride faster so they stay cool for longer. Thats how it works right? …Right?


From what Ive seen, windings are potted much more than many other motors. Good for longevity/durability and bad for heat.
The magnets are specced up to take higher temps, so I dont think its a big deal.


Correct with the wrong beta value you are getting wrong readings, in my experiance on high voltage setups you will get more heating, however you will notice that the motors temd to plateu around 80-90c


Which in Fahrenheit is still pretty hot to touch.

Which is kinda ironic, considering voltage is raised to lower current and therefore, heat. :expressionless:

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In curious if it’s the high voltage directly, or the fact that high voltage tends to bring along higher gear ratios and therefore more RPM and then more heat from iron loses? @Skyart ?


Not to mention that the people going HV are also more often the ones pushing the speed


So its a 2 fold issue

1 - people gear their HV builds for unrealistic speeds

An esk8 geared for speeds much higher than realistic riding speeds ends with a system that
creates heat instead of power i beliave this is called copper losses. Say a 50 mph build for a rider that goes on slow group rides is going to be super ineficient.

2 - people gearing down high KV motors and combining with high voltages

Iron losses - heat generated by very high rpm resulting in eddy currents in the stator core

One way to combat copper losses is to gear your system appropriatly, that is a few MPH higher than you usual riding speed. KV in my opinion is more important than gearing although not by much, its very important to select the right gearing/tire size combo.

To combat iron losses you could buy a motor with thiner stator laminations, how much this helps? I dont know and i was told by a few motor manufacturers that the tooling to make thiner stator laminations is around 20k…maybe one day i can splurge for this…but probably not soon…MOQs go up alot too. Reacher told me i would need to pay for the tooling and be buying 1000 motors per month :rofl::rofl:

Also i have NO idea how thin these laminations need to be, this is likely set up specific.

The more practical way to combat iron losses is to simply choose a lower KV motor…but here is another issue…lower KV motors are less powerful and can handle less current, so you also get hearing from people installing lower KV motors and driving them at 100amps.


Seems like you can’t win. So I’ll take more power, less efficiency, and a 800w+ charger thanks


Lol I’m with him, screw battery resiliency anyway, we accepted the money pit the first time we bought a vesc


You’re not my dad! I’ll ride my iron loss machine till it inevitably dies!


This is the attitude we need more of to push inovation


I cant hear you, 18S, 205kv, and straight cut gear drives go REEEEE


Me but helical

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Random tidbit of info, since we have very similar setups.

I ended up going with 20 degree Radium front baseplate, Moon 0 degree rear baseplate. ( this gives a 50*/30* split)

Front- Krank tall chubby 93a boardside, WFB chubby 88a roadside.

Rear - Krank chubby 96a boardside, WFB chubby 93a roadside.

Feels reallllly good now. Very carvy and also stable at higher speeds.( which for me is 25mph) gearing doesnt let me go faster which is for the better lol. I tried probably a couple hundred dollars worth of different Riptide bushings fyi. I weigh around 185-195bs.

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Nice! I’m actually using the moon 15° baseplates, been loving them.

I’m running a 93a WFB chubby barrel boardside and 93a Krank fatcone roadside in the rear. For the front, same formulas and setup, but using the normal size version of the bushings. Washers all around.

I found that using the chubby/fatcone setup in just the rear was enough to eliminate the weird fishtail wobble I was getting at higher speeds.

I’ve been absolutely loving this setup, it’s carvy as hell and remains stable up to ~40mph.

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Nice. I probably would have used the moon 15* up front if i had also used a 15* in the rear, but i tried 15/0 and it wasnt turning sharp enough for me. 15/15 im sure is better, but i wanted a definite split after previous experience with my last board. May have to do some experimentation based on your setup sometime just to see how it feels.