moxfyre

I just traded frames and got an 80s Raleigh frameset that I'm gonna convert to a fixed gear. The fork crown race is actually loose, so that it spins around the fork crown more or less freely. On removing it, I can see that there are some small grooves worn into the crown race seat. Also, the crown race seat is painted, which surprises me.

Is there any way to re-secure the crown race? I was thinking JB Weld, but that could be a bad idea. If I buy a new headset, will I be able to fit the new race tightly onto the steerer?

Thanks!

roadfix

Not all crown races have the same ID. Raleigh's is smaller, I believe. Check Sheldon's site.....he's got the numbers.

moxfyre

Hmmm... according to Sheldon, the Raleighs have the same crown race ID, it's just that the threads per inch is different. Yet another reason to not relish the idea of changing the headset

DannoXYZ 

Pull out the calipers and measure the fork. Then measure the ID of the race. You gotta have numbers. There's 27.0 and 26.4mm. You very well may have a 27.0mm race on a 26.4mm fork. The high-end headsets are pretty much all 26.4mm and the el-cheapo dept. store bikes have 27.0. Someone might have just installed a cheapo headset in your bike at one point.

moxfyre

Good point, Danno. I measured both and it's 27.0 mm race and 27.0 mm fork. So it's a JIS headset then, very surprising since the frame says "Made in England". Any thoughts?

DannoXYZ 

Huh? How can the race be loose and spinning then? It spins when fully pushed down on top of the crown so that there's no air between the bottom of the race and the top of the crown??? Bizarre...

There's two ways to fix this. The crude way to re-use that headset race is to use a knurling tool on the fork. This puts tiny little indentations into the seat on the fork where the race fits. The indentations have raised edges and it increases the OD of the seat ever so slightly to 27.1mm. Then the race will fit snuggly.

A better solution is to mill the fork down to 26.4mm and get a new headset. I like the needle-bearing ones, lasts a long time and very smooth action.

moxfyre

Yep, that's right

I may try this...

Okay, wouldn't I have to mill the head tube as well, so that it could fit the 30.2 mm OD cups??

sydney

I'd have a shop use the knurling tool and move on.Why dump a load on the pos anyway.

sydney

It happens. It's called manufacturing tolerances and having the min and max stack up the wrong way.

Nessism

I would cut the fork to 26.4mm assuming there's enough meat on the ledge where the race seat is cut. Any good bike shop, or framebuilder, with a crown facing tool could do this with little trouble. Knurling the seat will require finding a machine shop with the willingness to fool around with it (bike shops can not do this type of repair).

Good luck.

Ed

sydney

Had a slightly loose seat on a new Colnago fork. The shop where I bought it did the knurling fix real quick and it's still working 8 years later.

Nessism

Ok. Let me state it this way then, finding a bike shop with a knurling tool may be difficult and cutting the seat may be easier.

Cutting the seat to a more normal size will increase the availablity to headsets as well.

moxfyre

I may be able to find a knurling tool in the machine shop at work Dunno what it is, but if I find it maybe I can figure out how to use it...

vainamoinen

I had a simlar problem and used JB Weld as a liquid shim to fill the gap. It worked and the race is solidly attached now but I do have a little front end shimmy that I think is related. Not sure how that could have developed since I tightened the whole assembly while the JB Weld was still liquid so you would think everthing would self align perfectly but oh well it works.

DannoXYZ 

That's the problem, not letting the JB weld fully harden. What most likely happened was when you tightened down the headset, it wiggled the race and pushed some of teh JB Weld aside, creating the gap that causes the looseness. You want to just pound down the race so that it's fully seated on crown, then set the JB fully set. Then re-install.

moxfyre

Okay, so what you would do is pound the race all the way down, squeeze the JB Weld into the gap, and then let it completely cure?

I'm assuming that I should sand the paint off the crown race seat before trying this...

DannoXYZ 

Well, it would be interesting to take it apart and see if the race is indeed loose. What I've seen a lot of times is mismatched headset components. A lower cup from this headset here, an upper cup from this other headset, and a crown race from yet another headset. The shape and curvatures of the cone doesn't match that of the cup and the ball-bearing isn't located properly and things slide around, even when all the individual components are tight on the bike-frame and fork.

Sure, cleaning off the mating surfaces would help the JB weld adhere, but we don't really want to do that. You'll never be able to remove that race again. The JB's really used as a gap-filler, but I'm not how strong it is in compression. I would mix in some powdered metal filings to add some compression-strength to the JB. You end up with making another product called "Liquid Steel" or something like that, I've used it to fill 1/2" holes in motorcycle cases and it actually works very well.

So you can apply your glue-mix to the seat on the crown first, then slide the race all the way down and press it as far down as it goes, don't pound as it may jar it sideways too much. Then let sit and harden over night.

Grand Bois

I'm running the risk of being accused of smoking carpet, but I could swear I can remember reading in the instructions for a Ritchey WCS headset I recently installed that Loctite stud locking compound is approved for use on a loose fitting crown race.

moxfyre

Really? That sounds preferable to some kinda permanent welding compound... What is the difference between stud locking compound and regular loctite?

sydney

^^^^......Tried googling loctite or permatex?

moxfyre

Yes, I did. And what I find is that "Stud Locking Loctite" just means red Loctite as opposed to the blue stuff. Is that really what I need to use?

sydney

^^^....duno. would have thought there might have been some properties or application info.

moxfyre

Yes indeed, it was a loose race.

I stopped in at the campus bike co-op today and rummaged through their parts bin, found a JIS crown race. It fits my fork securely and is similar in shape to the loose fork crown race.

Now, I did indeed read your admonition not to mix and match headset parts :-) However I think I'm going to try this out, and see if I can get the headset adjusted properly even with the mismatched crown race. Here I go, inspiring the wrath of the ball-bearing deities...