Motor Choice 18s

I am stuck between two options for motors for my new build. I want a 50+MPH speed 2WD. The two options I’ve come to is a 5:1 gear ratio with the bioboard 65100 205kv 8” wheels 18s or 4:1 gear ratio with reachertech 7490 179kv motors. While both will give me the top speed I am looking for I am wondering which one will be more reliable and produce more torque/acceleration. Does anyone have any experience with either of these motors and the power they deliver? Thanks guys!


What ESC will you be using? 205kv at 18s sounds like a lot of ERPMs, which the ESC might not be able to handle.

Usually the greater the gear ratio the better, but this is an exceptional case.

Great question! I will be using the ubox v2 by spintend. It can handle up to 22s 200a.

Hmm, assuming your battery sags down to ~4V per cell, that’s only 103k ERPM worst case. With duty cycle limits it’ll be a bit lower. I’m pretty sure the ubox can do at least 100k ERPM, so I guess you should be safe with the first option.

As for motor quality – a lot of people have various issues with the reachertech motors. If you buy custom ones from Radium maybe they’re okay, but I would personally go with the bioboards ones.


:neutral_face: uh oh I haven’t been paying attention what kind of problems?

i see you took a liking to my speed :joy:


Yeah I have an addiction of flirting with death as much as possible🤣

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Most notably is the sensor wire exits from the can are sus. As well as 2" of solid copper phase past the exits.

Not sure if your batch had those issues.


get some bindings too😘

Just gonna drop this here

Great on 18-20s

I also address the concern we have with reacher V4 motors by reinforcing phase wire exits and adding green loctite where it’s omitted