10mm axle into 3/8" horizontal dropouts...
 

Any advice on how to proceed?

I'm trying to cram a SRAM i9 hub, 10mm axle, into my Swifts 3/8" (9.5mm) horizontal dropouts.

I could just force it in, but as I'll need to be able to smoothly adjust chain tension, that's not the best option.

I am prepared to lightly remove some material from the dropouts. It won't take much, but I'll want to be consistant for the length of the dropout.

The other option is to remove some material from the axle. This would probably be nothing more than filing away the raised part of the thread along the top of the axle, on both sides of the hub.

Preferred method? Any "gotchas" to look out for?

http://www.booboodog.net/images/bike...ut-10mm-ax.jpg

I've done this with an anglegrinder, but I think for the sake of .5mm on a nice bike, I'd likely to it with a needle file.

The axle or the dropout?

I have no experience with geared hubs, but I'd try filing the axle first, because filing your Swifts dropouts isn't reverseable. That is, IF its a standard axle that can be replaced if you decide to use the i9 on another bike. Removing 1/2mm of thread from each side shouldn't compromise the axles strength.

That's my impression, too.

Since Sram uses a 10mm axle and Shimano uses a 3/8" / 9.5mm axle, I was surprised this problem doesn't pop up on these boards. I would bet there are a lot of Shimano 9.5mm axles "floating around" in 10mm dropouts without a bit of a problem.

I doubt I'd be able to replace the i9's axle, but I don't suspect it'll ever be an issue (if I do this right).

Hang on... the axle has flats... those must be aligned with the dropouts.

Nope, I wish it were that simple. The axle flats are aligned with the shifter do-hickey, an sit vertically.

The tabbed washers do the rest.

http://www.booboodog.net/images/hub/i9/i9-washers.jpg

Ok, that was easy.

Couple of strokes with a flat file and it was pretty obvious that was going to be an arduous process.

So broke out the Dremel with the reinforced cut-off disk, and (improper technique) lightly massaged the axle with the side of the disk, maybe at a 15-20° angle from flat. The material came right off with my RPM set around mid-range (guessing around 20k RPM). Perfectly controllable.

I should have only done one half per axle like I wrote in one of the prior posts. I actually took it down to 9mm on both sides, but it still fits nicely and won't be a problem with the tabbed washers in place.

http://www.booboodog.net/images/hub/...xle-ground.jpg

I did the dropouts with my angle grinder, but on cheap oldies, not anything nice. If I'd had a Dremel, however, I'd have made a loverly job of it.

I'm finding new uses for the Dremel all the time. I don't know how I got along so long without one. This particular example was brilliant, if I may say so!