Spacers for hub motor

[Jessiedog1234567]

I have bought a hub motor that I am waiting on that I know will need spacers (probably 10mm wide on each side) to fit properly between the swing arms on a small motorbike. When it comes to it will the spacers have to have a hole shaped to the flat end of the axle as in the first photo or can they just be round as second photo (obviously the axle is 14mm at the thickest and so would use the relevant sized spacer.) Also does the part of the actual hub motor that the spacer comes up against spin or is it just the outside of the hub motor, i.e would there be friction there and if so is a washer necessary between spacer and hub?
Thanks

 

[Voltron]

It sort of depends on the motor axle... some of them have a very thin step that the spacer goes against. If you use the washer with a round hole instead with the flat sided hole, there isn't enough contact, and really tightening the axle nuts can make the spacer start squishing over the step. If the axle has a big step where the spacer rests, then it's not an issue.

And the spacers are resting against a part of the motor that doesn't spin.... hopefully! So if the wall thickness of the spacers is too much, it will scrape against rotating parts sometimes, which is bad, obviously.

 

[Jessiedog1234567]

Thanks again Voltron , really helpful advice. I guess if there is a thin/small step it would be better to use several of the "shaped" washers to make up the difference.

 

[Voltron]

Exactly ...

 

[MadRhino]

If you use spacers, where do you plan to fit the torque plates ?
Is the axle long enough that you will have room to put them outside ?

IMO, unless the motor has a very long axle, those spacers should be pinch drop outs or bolt-on through axle torque plates.

 

[Chalo]

I guess if there is a thin/small step it would be better to use several of the "shaped" washers to make up the difference.

You would only need them at the clamping faces of the axle. The rest of your spacers can be the normal kind with a round inside diameter.