8mm vs 10mm motor shafts

What is he difference between 8mm and 10mm motor shafts other than the size? What would you buy?

Pulleys are easier to get on 8mm shafts, and they come smaller. Also, are they round shafts or D shafts?

Is there any advantage to using a 10mm D shaft motor?

I’m assuming you’re looking on flipskys website for this, don’t get one of those. Stick with 8mm bore and your life will be easier.


Idk, wouldn’t say it’s more difficult to get hardware for 10mm shaft.
Only reason I would stay away from 10mm would be if I plan to buy a gear drive that works only with 8mm shaft.


Or need an htd5m belt pulley with less than 15 teeth. 10mm shafts are dope. They make me feel cool. I think this has been an opinion


10mm shafts are better in every way that I can think of. Not only will the motor shaft be stronger, but the retaining methods of pulleys and gears will improve as well. Adhesives like loctite retaining compounds will have more surface area. The moment arm force of set screw friction and adhesive strength will be less.

The cons:

Less available pulleys and gears currently (it’s not as popular for our market)

Has a higher minimum gear/pulley size since the keyway will begin to interfere.

Really though it’s just not a standard and the benefits mentioned above are kinda unnecessary. Very few broken motor shafts


Who needs a keyway anyway ??? :stuck_out_tongue_winking_eye:

But seriously, I found all those low teeth count options are most of the time not the best choice anyway.
Like a 13T pulley or a 8T mod2 gear.


I think the bigger diameter only matters for a single digit fraction of Esk8.

If you are one of those lunatics, then absolutely 10mm. If not, leave it alone.

If you aren’t sure which fraction you precipitate into, then it’s 8mm, and that’s ok.


That’s what she said?


To elaborate on my opinion earlier, they can also change the path of least resistance in a mechanical failure. For instance: like, if a stick gets in the drive, maybe the mount breaks instead of the shaft lol. Obviously, an 8mm steel rod won’t just quit being a single rod. But it is entertaining to think about how a reinforcement ‘here’ can destroy a thing ‘there’. More so in eSk8 than the rest of anything lol. But I wouldn’t go through the obvious challenge of finding a 10mm pulley :yum:, just to cut a D-shape in the shaft.

I do, definitely like keyways though. They don’t really matter, but hey, opinion. PSA: never stick a grub screw into a keyway.

Are people still running belts? I’ve been away for a while.


I actually use both its def. harder to get 10 but @dickyho as a source for 10s means I don’t really worry

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Can confirm! I’ve got a few of them!


Care to elaborate? I was just about to do that :rofl:

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Don’t, I have fouled the keyway just enough to almost fuse the pulley to the shaft. Second hardest repair I’ve ever done on a skateboard ever.

I destroyed the pulley and had to file and sand the shaft to get a new pulley back on. THANKS @dickyho for all the pulleys!


:rofl: righto, loctite 638 ftw then.


As long as you can torch the locktite without burning other shit lol!! I’ve had issues with torch angles…

I couldn’t get loctite 638 to hold on 8mm shafts with 6374 170kv motors for the life of me. Always loose in 500km.
Now with 10mm shafts I don’t have any issue with 63100’s

for small 50 motors, 8mm is better. leave more space for the core.

but for bigger motors like 63 motors, bigger shalf would be more strong and stable, have more torque, not easy to slip.


if a kit already comes with pulleys and 10mm shaft is there any point in switching