Spur gear approach

Was asked to show pinion to spur build.

scuff wheel surface and used windshield urethane to fill gaps and attach gear. Used a wire jig to 0 the gear run out. after urethane cures drill and machine screw wheel. This method was cheap very effective. I have 3 builds using this method. This allows gearing for an inrunner motor @ 2000kv 4s with nice performance, inexpensive components, lowers overall profile and weight on a 70mm wheel. Found on a soft wheel, gear to wheel run-out would distort under hard acceleration and braking. So I built a hub. The hub and gear combo now run independent​ of the wheel. The axle needed material removed to accommodate the extra bearing. Run out is checked in a wire jig and the wheel is drilled, then screwed. top speed 35mph(GPS) 1350kv 8s 135deg motor temp cruising over 20mph for 5 miles. The setup works well, just a different approach.


Awesome, reminds me of the Jed Board direct drive system. One questions though, how is the low end torque on this thing? Seeing as the motor is 2000kv. However, the gearing ratio must make up for some of that. Cool that you can run it on 4s only as well. Nice job!


I’m running a 5s on one of the 2000kv with good motor temp. The general rule here is when you step up the voltage, lower the motor kv. The 2000 kv motor I’m using is rated for 135a @18.5v. The 1350 8s is rated for 85a @ 38v, so correspondingly, raise the volt and the amp required drops. Both setups have heavy torque and accelerate hard from low to top end speed.


hah you go tto tell me how you use this Wire jig method? I assume you look how big is the variation in the spin, right? Ive seen similar technique used on bicycle rims.

Theese are some ‘beefy’ motors to be honest! Do you know what is their temp rating?

135A sound quite a lot already… should do a calculation on what wattage that is!

You mentioned 135 Degrees… Are these Farenheit degrees or Celsius degrees?

IF 135 F, then that is 57.2222222 degrees Celsius. Otherwise if you run at 135C then that is some high temperature… ebike motors can do up to 120 C I think. Depends on what type of heat level magnets you got, so ive heard.

@Okami The manufacturer build sheet on the 2000kv 135a motor claims 2800w. I have found on these inrunner motors, using motor temp to fine tune your gearing to your riding habits works well. And keeping these small inrunner motors under 165deg Fahrenheit is a priority. The jig is setup just like truing a bicycle wheel :+1:

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Is it noisy? JED boards had some issues with noise, which were solved by some kind of nano technology…would different material like nylon help? Can the drive system transmit enough torque? the pulleys are quite thin compared to 12mm belt…

@aigenic Your not going to sneak up on anyone. Tried nylon and aluminum. Both wear out quicker than I deemed useful. Metal on metal is strong and lasts. In my opinion, it has less mechanical resistance and stronger then a belt. The 2000kv motor 135a @ 2800 advertised watts lays down near 3.5hp on the calculator. This setup handles it fine.

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@MoeStooge Yeah, it probably has less resistance…jed board made a video where the their drive system totaly outperformed inboard’s hub motors in terms of free push…If you had just nylon wheel pulley, which doesnt wear out that quickly and metal motor pulley it could be less noisy, am I right?

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@aigenic My experience with nylon is less noise and less durability. For me the trade off was not worth it.



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Ok so where can I get a mount for this type of drive

@jaymu86 Diy. Made my first couple of mounts that worked well from a block of aluminum, bench vise, hacksaw and drill. You could also adapt what’s out there in the Diy world.


Where we’re at today. IMG_20180701_094409_222 IMG_20180602_113943


No fear that a Rock could get stuck into the gears? Just because it didnt Happen yet doesnt mean that it could Happen?!

Fender on top or below the gears would be an easy solution depending on drive rotation.


150mm Paris hanger. 4200watt (5hp) single. IMG_20180818_192144919


oh boy, sounds crazy! can’t wait to see it!

Mod1. 8 hardened steel spur HS pinion open gears and dry. Lowest resistance for a geared option, strongest and most reliable with nearly no signs of wear after a year of riding/ racing on 12kw. Absolutely Amazing.

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