rear dropout spacers c washers vs round? For Cromotor

I need to spacers to space out my rear 165mm dropouts to fit a cromotor and was wondering if there is any difference between using Round washers or C washers, OR Washers that are not round but are more oval shaped to fit the 14mm axle.

To get C washers that are made for hubmotor axles seem to be expensive and are wondering if it is worth the cost?

Someone said that C washers help to not push on the wire that comes out of the cromotor but I do not see how that could make much of a difference.

Cromotor axle is 16mm x 10mm w/ a 1.5thread pitch

if you want/need "C" washers you can get them from Jeremy (aka zombiess) greyborgusa.com - they are fairly inexpensive

or you can make your own, i have done this by using M10 washers

newb said:

Cromotor axle is 16mm x 10mm w/ a 1.5thread pitch

if you want/need "C" washers you can get them from Jeremy (aka zombiess) greyborgusa.com - they are fairly inexpensive

or you can make your own, i have done this by using M10 washers

Click to expand...

How did you make the washers by using M10 washers?

QuestionMan said:

How did you make the washers by using M10 washers?

Click to expand...

the M10 washers i used had roughly a 20mm diameter. just cut out a 9 + mm gap and filed out the rest till i had a nice snug fit.

Pretty hard to make a definite correct answer without good clear pictures to see exactly what problem you need to solve.

Depending on the thickness of your dropouts, you might need more space for the wires to exit. Don't put a pinch on the wires by tightening the nuts. But if there is plenty of room, the wires won't pinch till you spin the axle. In that case, no washer can prevent the wire damage. An insufficient torque plate won't cut it. You gotta prevent any movement, especially if you regen brake.

Because of the way the wires exit that motor, you might need to enlarge the holes on D shaped washers that are used for spacing inside the dropouts. I don't think you can use C washers on the inside. They are for outside the drops. On the inside, if you cannot use the stock axle shoulders, then using a c washer would be vulnerable to the washer spreading, and the nut getting loose.

Personally, I would never want to use a really strong motor running over 2000w with anything less than a very good pinch dropout.

As Dogman pointed out, C washers can spread, causing them to get pushed out. And a stack of normal washers can have a slight spring effect, so that under certian conditions, they get compressed and alow the nut to loosen.

But all you need is a spacer, you can use several things. Best might be to use some of Doc's torque arms, but fitted inside the dropouts. It would be best to glue/bolt them, but you could just use them as spacers. they are a "C" shape, so there is clearance for the wire.
The next best thing would be a set of nuts. since these are being used as spacers, you can use a larger size where they need to clear the wire, or use the correct size but file out the threads in the area where you need clearance.
You could also use a piece of thick walled steel tubing. this gets tricky as you would need to make sure you cut it perfectly flat. however, you could then make the spacers the exact size you need.

im using a nut ,the same that came with the motor with the threads ground out and cut a chunk out for the wires ill take some pics. and also a nut on the drive side for a spacer for the single speed. this is goin a a Ti Mukluk with a 80mm rim and 4.8 tires with studs . pics to come. custom dropouts too