Carbon fork leg/brake rotor bolt head interference
How can this be? I'm building up a Niner MCR with Niner rigid carbon fork. When I mounted an Avid G2 brake rotor to my Chris King ISO hub and tightened the skewer, I immediately noticed pronounced rubbing. Assuming it was the BB-7 caliper, I loosened both the inboard and outboard calipers. Still no joy. Then I realized the bolt heads on the brake rotor were rubbing directly against the inside of the carbon fork leg. Aiiieeeehhh! What's going on here? Do I need a spacer or something? I've never heard of this problem before.
I just looked at mine, which is the newer (G3?) Avid rotor on a Hope hub and there's about 1/8" clearance at the bolt heads.
Thanks for checking, cycleboy. I've bought everything for this build from my LBS, so I know they will help me troubleshoot the problem. Damn glad I've established a relationship with a LBS...it helps at times like this.
Is the fork NEW?
I was reading JAN 2010 copy of MOUNTAIN BIKE mag and they had a write up on the NINER carbon fork .
Here is what they said:
2 stars (1 review)
Issue: Jan 2010
Page: 60 Editorial Review
This carbon-fiber fork is reinforced with stainless-steel scuff guards where the axle and QR bite. Even with the bolstering, it's one of the lightest forks on the market. Installation was a snap thanks to the simple post-mounted discbrake bosses; the cable-tie hydraulic hose guides keep it clean. (The maximum rotor size is 160mm—go any larger and you void the warranty.)
Our early-production model's only trouble spot was at the bottom of the left leg, where the amount of material interfered with some hub flanges. Niner owner Chris Sugai assures us this has been addressed on subsequent production runs. On the trail, the fork tracked well with no unwanted flex and no chatter from the brakes. On all but the rockiest sections, this fork offers dead-on handling.
Thanks, scyule. It is a new fork, but I don't know when it was manufactured. I'll mention this when I'm at the bike shop.
It's the flange spacing of the Chris King hub. I have a Hope front hub on my One9 that has a lot more clearance than the Chris King hub on my A9C. You need some shallow head rotor bolts.
Thanks, collideous. It's either the hub, the fork, or the combination of the two. Do you know where I can find shallow head rotor bolts? Hard to find?
Either take one of your current bolts to your LBS to see if they have some with a shallower head or check shops like Jersey Cycles, they have them in Ttitanium.
Here's a pic of my setup.
Thanks - I'll start with my LBS.
So I stopped at my LBS after work today and after much discussion and research, the mechanic figured out that the "problem" was with the Chris King ISO hub. I put problem in quotes because there was nothing technically wrong with the hub. When I bought the hub from the shop, it came with 15mm thru-axle end caps. They swapped these out for standard skewer end caps for me. Well, it turns out the end caps are not identical; one is longer than the other, and needs to go on the disk rotor side of the hub. He switched out the end caps and - boom! - problem solved. Although it created a new problem...I need to redish the wheel now, but that's not a big deal.
I'd put this on the Chris King forum, except there isn't one.