I normally run a formula hub in my carbon rigid forks with no problems but the wheel is getting bit tired so I put an old but slightly less tired XT hubbed wheel in. However the disc bolts foul on the fork lowers. I had a couple of different sorts of disc bolts to hand, domed Allen and Torx but both made contact. How far can I space the axle away from the fork lower and still get a decent purchase in the dropout? Or are there any particularly flat disc bolts I could try ? Or any other solutions?

How far can I space the axle away from the fork lower and still get a decent purchase in the dropout?

I wouldn’t do anything to spread the legs, myself.

Sounds like a no-go to me 🙁

EDIT: try to find slimmer lock nut that fits the axle?

There’s something not right here… Brake mounts are standardised so no matter what you do with the hub, the rotor and therefore the bolts should be (more or less) the same distance from the fork. Any chance the XT hub’s axle is missing a washer/nut/spacer or has it on the wrong side?

Brake mounts are standardised

*should* be standardised, in reality there’s difference between hubs, CK and Hope are different by a noticeable amount, got some DT and WTB hubs that are different again, not by much, but 1/2 a mm can be the difference between clearance and contact.

But I second what NW said, unless your formula was also very close and only just cleared then I’d be checking the XT hub over just to make sure.

How much do they foul by? are we talking fractions of a mm or something more?

FWIW, I’ve got a couple of forks that I simply cannot run certain hubs on, and a Cannondale Fatty that is damn close with some hubs.

The bolts foul by a significant margin, enough to prevent the wheel turning without a hefty heave and much grinding of metal (the forks have a metal dropout) Without stripping the axle the nuts and spacers look normal. Wouldn’t a slimmer locknut bring the disc closer to the fork leg? Perhaps a fatter locknut?

Sorry I was actually trying to work for a minute when I wrote that…

But yeah, another locknut 😉

I think I will give that a go but not too much as I am conscious of what was said about spreading the legs. Having said that, the legs pull together quite a lot with the qr so there should be some play that could be taken up with a spacer before the legs actually spread.

I had a similar problem – turns out when I stripped and regreased the wheel, I’d put the cones/spacers back in the wrong side. Re-rebuilt the axle, and all was fine

I had better check that too!

And reading that again I should really say “another” as-in a different one of some sort.

I think I need a little lie down, sorry.

if the axle spacers were significantly wrong then the wheel would also be sitting off to the side in the fork legs, is it central?

Seems to be with a quick look.

Is there a centre lock to 6 bolt adapter on there? Does that push the disk out a bit?

Sometimes you need to use disc bolts with a lower domed head. Worst case on rigid forks there’s no problem spacing the axle a little, but it’s not ideal as you then have to ping the wheel in.

You need low-head socket capscrews. Like a normal allen-head bolt, but the head is much thinner. A decent fastener supplier should sort you out. Make sure you use a good, new allen key, or you’ll round out the hex. (I had a formula hub years agou that suffered fork-fouling with any other type of bolt)

Can you post a picture?

I think Hope used to do discs with countersunk holes and countersunk setscrews.
Edit

I have finally managed to do it by putting a thick washer between locknut and fork lower and by taking the washers off from under the disc bolts but the clearance is fag paper tight and there isn’t much axle in the dropout. The countersunk bolts and discs would definitely make a big difference. Now off to ride it and make sure fork isn’ t going to fall out!

its an xt hub right? old one with steel axle and cup and cones? can you do some jiggery pokery with the locknuts and so on to space it over a bit

nbt – Member
I had a similar problem – turns out when I stripped and regreased the wheel, I’d put the cones/spacers back in the wrong side. Re-rebuilt the axle, and all was fine

Same as that, mate brought a wheel round and had done the same.

taking the washers off from under the disc bolts

I can’t be the only one who has never used washers under disc bolts!

You mentioned “domed” bolts – you can get disc bolts which are far flatter than those.