Right I’ve got a bizarre problem,

Using a roval carbon hub with a niner fork there is an issue with interface when I clamp the front 15mm axle up.

However there is a 3mm gap.

If I put a 15mm inner diameter washer 3mm wide in the gap and it stops the interface happening, will it have any nasty effects?

have you measured everything (not the gap) to see whats out of spec?

When IS doesnt work 🙂

Id go with the 3mm packer. Not enough to cause any problems to the fork alignment IMO. That or take a file to the niner fork maybe! 😉

What Ghostly Machine said. I’d be trying to find the reason why 2 standard parts don’t fit. What happens if you put another wheel in there?

I haven’t got any calipers to measure what’s out. I’ve got access to lathe so I can make an exact spacer. I’m not skilled enough to knock a new hub end cap up that’s 3mm longer though!

Have you measured the hub width?

The problem I think lies with the shape of the roval hub. The flange sits so wide compared to any other hub I’ve ever seen. Then the niner fork is flared at the wrong point.

Measure hub and fork – work out which is wrong – if the hub, probably need to fix that/send it back. If its the fork, then I would personally just clamp it up and move on. You’re either OK with it being off spec or not, adding a spacer isn’t dealing with the underlying issue of do you trust a carbon fork thats been made that off spec…

The flange sits so wide compared to any other hub I’ve ever seen. Then the niner fork is flared at the wrong point.

Ah, so the shape of the hub on the right (of the picture) is butting up against the fork and pushing it apart. Is that what you are describing?

I don’t think there would be a problem if it wasn’t for the shape of the hub.

If I was to put another 100mm 15mm hub in there it would just nip up as I do the axle up, but it cant due to the shape of the hub and fork.

Why Roval have made a hub where the flange sits so close to the edge is beyond me… maybe it was an attempt at boosting before boost hubs became available.

Ah, so the shape of the hub on the right (of the picture) is butting up against the fork and pushing it apart. Is that what you are describing?

No it interfaces when I clamp the fork down. When the fork is relaxed it has just enough clearance and would work if I put a 3mm spacer in the fork so they clamp up to the hub in their relaxed position.

Not sure if that makes sense. The interference I have drawn happens if I tighten the axle to take up the 3mm.

Can you post a picture, it’s not entirely clear what you are describing. Is the wheel fouling the fork and won’t rotate if you just nip up the 3mm gap as is?

edit – cross post. I see now. I wouldn’t be enamoured of putting a spacer in unless it was positively located in some way. I think there’s a risk of it slipping under hard cornering. Would be more concerned about that than spreading a fork leg 3mm, unless you are a really heavy and hard rider that is already loading the fork towards the limit of it’s design, (even then, it should be engineered with a significant safety allowance)

Oh hang on, it’s a bolt through, so positively located anyway. 😳 Yeah, I reckon you’ll be OK as it’s only packing out a gap that’s there naturally. You’re not even putting any extra forces into the fork leg by bending them inwards.

Oh hang on, it’s a bolt through, so positively located anyway. Yeah, I reckon you’ll be OK as it’s only packing out a gap that’s there naturally. You’re not even putting any extra forces into the fork leg by bending them inwards.

This is what I thought, wasn’t sure whether having the washer not an integral part of the hub mattered or not?

I haven’t got any calipers to measure what’s out. I’ve got access to lathe so I can make an exact spacer.

Just me who smiled at this? “I’d rather spend a long time on a piece of kit costing thousands than find out what the problem is with a £10 bit of measuring equipment.”

I’d just chuck in the spacer. That’s all the end cap is anyway. If you clamp the forks up you’ll load up the bushings, which is bad.

Seems a poor design anyway, most through axles I’ve used have a step in the axle to do the clamping, rather than relying on the fork being bang-on the same width as the hub.

Space it, is it going to rub with flex in use though?
Fox forks & Chris king hubs used have compatabilty issues, took a file to my forks ( early 36s from memory)

I’d just chuck in the spacer. That’s all the end cap is anyway. If you clamp the forks up you’ll load up the bushings, which is bad.

They are rigids with 15mm bolt through.

I’ll get some calipers at the weekend. I think its a bit of both, hub being 98 and a bit and the fork being 101 ish. Hard to do with a ruler though which is all I’ve had to hand.

I’m interested in if I can get away with the spacer though, I’d like to run both together if possible. Both are used purchases so its not a case of sending stuff back.

Thinking about it, I can see what space my wheel off my trail bike has, that will help diagnose the actual issue of the 3mm.

Space it, is it going to rub with flex in use though?
Fox forks & Chris king hubs used have compatabilty issues, took a file to my forks ( early 36s from memory)

No with a 3mm spacer taking up the natural gap then there is space between the fork and the hub flange. For the hub to rotate to flex and interfere the whole axle would have to move about 30 degrees which can’t happen. Flex in a wheel isn’t seen at a hub flange.

What I was getting at is with the 3 mm spacer fitted what will the gap between flange and fork be? Will be a very close gap in which case a small amount of flex may case issues.
Not a major concern but worth checking.

It’s about 3mm.but that gap is pretty much horizontal. No amount of flex is going to mean the flange moves 3mm laterally. A rim yes, a hub flange no.

They are rigids with 15mm bolt through.

If the “relaxed” gap with no load on anything is 3mm. Just make the spacer, it’ll be fine.

Doing that will be far less hassle than any other solution. Might be worth whipping the tyre off to check the rim still sits centrally (though with a fork thats already slightly too big OLN, i don’t know if you’d be able to tell!)

Thanks, I guess what I’m really asking is…

Does having a 3mm spacer that isn’t actually part of the hub end cap affect performcance.

For example if I was to take a Hope pro11 and cut 3mm off the end of the end cap, but then include that when putting it all on the axle, how would the hub perform compared to if it had been attached.

Use the 3mm washer. It’s fine.

Although I find it laughable that with expensive forks and wheels it’s a part costing a few pence that’s needed to get it all working 😀

For example if I was to take a Hope pro11 and cut 3mm off the end of the end cap, but then include that when putting it all on the axle, how would the hub perform compared to if it had been attached.

It will perform exactly the same.

For example if I was to take a Hope pro11 and cut 3mm off the end of the end cap, but then include that when putting it all on the axle, how would the hub perform compared to if it had been attached.

With anything except QR it’ll be fine.

Only proviso is that i *might* prefer to have both faces slightly knurled to take a bit of shear load off the through axle. Saying that, not all the through axle endcaps i’ve seen have a knurled end……..

I also have Roval wheels that I run in niner forks and have the same issue. I just installed a washer on the disc side and all has been fine. Ridden the Dirty River twice and haven’t had any issues. I also carry a spare washer just in case.

Googling that hub and looking at some of the images is interesting. I can’t believe you’re the first to have that problem.

Daft question time. They do different end caps for those hubs I think. You couldn’t have odd end caps – say one boost and one non-boost on a boost set of forks?

That would give roughly the effect you’re seeing I think.

A boost end cap ought to sort the problem (and is available I think) so a 3mm spacer should be fine. Probably.

No the niner fork is non boost

I also have Roval wheels that I run in niner forks and have the same issue. I just installed a washer on the disc side and all has been fine. Ridden the Dirty River twice and haven’t had any issues. I also carry a spare washer just in case.

That’s interesting, I’ve got the issue on the non disc side. Disc side has clearance and disc sits in the right place.

Measurements needed.

My Hope hubs fitted perfectly in my (QR) fork. No noticeable gap even pre-tightening/clamping.

Is the fork >100mm or the hub <100mm?

Or have I got my standards wrong?

You can see how far the flange is out compared to a normal style hub.

I think they tried to get the flanges further apart and when combined with the step in bulge of a rigid niner fork it’s just not enough clearance.

The fact there is a 3mm gap is almost a saving grace in that I can pack it to allow this to work.

Thanks for all the input folks!

Vernier callipers are on offer for a fiver at Screwfix – treated myself this week. They are IMO ok and far more accurate than my work!

That should work.

i wouldnt add a spacer as it will try to bend the forks. This will make the bushings rub and will cause wear issues.

Award for the guy who didn’t read the thread properly goes to…

The forks already have a 3mm gap fella and they are rigid forks

That’s interesting, I’ve got the issue on the non disc side. Disc side has clearance and disc sits in the right place.

Now you made me think which side I put the spacer in, I know I added one as without it something just rubbed on the fork, having been out and checked it is the non-disc side I put the spacer in, and not the disc side.

The wheels run fine in all my other forks, and my Hope wheels run fine in the Niner forks.

That’s great. Mind if I ask what size spacer you went for in the end? I’ve turned a 3mm one and it’s a tiny bit big. Going to go for 2.5mm. Doubt I’ll get this one in the chuck to take 0.5mm off it

chilled76 – Member
That’s great. Mind if I ask what size spacer you went for in the end? I’ve turned a 3mm one and it’s a tiny bit big. Going to go for 2.5mm. Doubt I’ll get this one in the chuck to take 0.5mm off it

Soft jaws? If not, it’s probably easier to just turn and part off a new one.

Sorry missed your post back to me, I just bought some washers off eBay – like these Ebay Link

I think I got the M16 ones, which the chart shows as 3mm thick