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Discussion Starter · #1 ·
Just built up a new bike with a Ritchey WCS full carbon fork and a Chris King headset. The CK crown race will not fully seat on the steerer (I tried, and so did a mechanic at my LBS). There is about a 0.5-1.0mm gap between the fork crown and the race, the gap is uniform all the way around so there is no doubt that the race is on straight... It seems to be caused by the steerer flaring out a little as it goes into the fork - the race is chamfered in this area, but I guess not enough to mate properly... Anyway, I installed the fork on the bike and the steering is perfect. I have ridden it for about 150 miles without trouble and without it moving.

Questions: How common is such an occurance, and does it matter? Does the fork crown contacting the race provide reinforcement in any way, or just ensure that the race is on straight? Is there something I should do about this? Should I remove the race and lightly sand the inside of the race? Or lightly sand the base of the steerer?

Thanks for any advice.
 

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Right tool for the job

dwaharvey said:
If I want to do that myself (chamfer the race) should I just use emery cloth, or is there some better (more precise) method?
I would definitely have the crown race seat chased by someone with the proper tool. The crown race should be supported by the seat - otherwise the entire weight of the front end of the bike is loaded onto the crown race, which is hanging in the air. I don't think that is a good situation, and could lead to failure. Chasing the crown race seat with emery cloth is not likely to give you a perfectly centered and even seat, and so this could lead to premature failure of the head set bearings. Find a shop that has the tool and the skills.
 

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Call King. They can supply and oversize crown race seat to deal with your problem. If it were an alloy steerer, than you would most definitely want to mill the crown race seat correctly. With the carbon version, you will either want to warranty the fork or get a different crown race. The race seat should have been checked prior to purchase, but very few people do that. The problem doesn't lie with the race, but with the race seat on the fork crown. Fix the problem.
 

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Discussion Starter · #8 ·
Called King, they don't offer oversized baseplates/crown races, just undersized ones. They said the steel baseplate is too hard to remove material from easily, that I should have the fork faced at the LBS. I am just a bit worried about removing carbon from the steerer, especially since the Ritchey Warranty card expressly says not to modify the steerer in this region in any way.
 

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I have a Look fork (HSC 4 Full monocoque) that has milling around the crown (in the resin) so that the race fits snug.

I wouldn't use the cutter for metal crowns on carbon, they must use a grinder mill or something for carbon.
 

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Would it be possible to correct this problem by simply using one of those split races? I've seen them supplied with Cane Creek headsets and FSA. Not sure if they fit with a King, but they seem to help with the roughness of carbon.
 

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Discussion Starter · #13 ·
The latest...

I appreciate all the advice. I have looked into a number of things, calling both CK and Ritchey. It seems that the Ritchey fork meets their own spec, and is designed to work with their headsets. They claim not to have heard of any troubles with this sort of issue. I have already sent the fork back to them and had them check that it was OK.

I have a friend at the LBS who looked at the Ritchey spec from a CAD drawing and he reports that the flaring of the tube at the base of steerer is indeed larger than the chamfer on a CK baseplate. So two perfect specimens from the two companies will not work together without modification. So what to do about it?

I am worried about facing the fork as I said, because I don't want to create any stress-risers that might lead to it failing and me losing my front teeth. I talked to Ritchey about the issue today and of course they said that any facing of the fork steerer would void the warranty and that they thought it was a bad idea.

It turns out that my friend runs a side business making Ti jewelry and has a machine shop in his garage, so he is going to try to put the CK base plate on his lathe and increase the chamfer slightly... only concern is that the CK base plate is made of a very hard stainless steel that will be very hard to cut. I called CK because I found out they also make a Ti baseplate that I thought might be softer (based on experience of Ti vs Steel cassette wear). CK claim they don't know which is softer ("Ti is very hard"), and say that they can't give me any advice about doing such a modification because of liability and warranty issues.

Whole thing seems crazy, Ritchey and CK both saying their stuff is perfect and neither being very helpful.

Hopefully my friend can come through with his lathe. If not another friend of mine had the idea of making a 1mm thin spacer to go under the base plate and bridge the gap between it and the fork crown... any thoughts on that idea?
 

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So, it sounds as if Ritchey has gone off the reservation and made a fork that isn't a standard design. This is done more often than it should be, and it's typically for marketing or aesthetic reasons. From what it sounds like, you've got a couple of options - you could try different headsets until you find one that sits flat on the crown race seat or you could use a different fork. My advice would be to abandon the Ritchey design and ride something like the Reynolds fork - it sounds like your LBS is all over this, so hopefully they realize that Ritchey has dropped the ball and will let you return the fork. I would probably eschew riding that fork crown setup, since as someone else said, the race seat needs to bear the rider load.
 
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