Earl Grey

I'm trying to set the crown race on a new 1-1/8" threadless fork (All City). The crown race is Cane Creek.

I am using the dedicated Cane Creek adapter and the Park CRS-1. I have tried first supporting the fork with my hand and tapping firmly with a hammer. Then with the fork over a 2x4 (insulated slightly with carpet). After every attempt the race is 'sorta' stuck on but can be popped back off with my fingers.

I could definitely hit it much harder, but I am reluctant to really whale on the thing, because a) I don't think it should be necessary if everything was the right size and b) the race is a very small, light part.

The race seat(?) area of the steerer has visible machining marks (almost threads) and doesn't look super-cleanly done. The steerer is (I think) ED coated after machining, so it's matte black, not bare metal and hard to see if there are any obvious high spots of finish or steel.

Measuring with calipers I make the steerer 30.08-30.12mm. The inside of the race is tricky to measure with calipers, but I get about 29.9mm. The CRS-1 instructions suggest a .1 to .2mm interference fit is acceptable, so this would be right at the outside edge (if I'm measuring accurately - I don't completely trust my skill with the calipers to the .01mm range...).

I'm thinking the best option is find an LBS with the equipment and have the fork crown milled.

I have a tendency to buy tools even when the probable payback period is many years, but I draw the line at the fork milling stuff (and I wouldn't attempt it anyway).

Am I thinking along the right lines?

bobotech

We have a race install tool that is pretty much a pipe that fits over the steerer and has a reverse race surface and a solid top for whacking with a hammer, probably the same thing as the park crs-1. I will hit the thing pretty hard, like I'm trying to drive a nail into hardwood. I'm not a wimpy guy nor do I treat it wimpy. I hit it hard, I am not tapping it. I use a solid metal hammer, using a deadblow, rubber, or plastic hammer would be futile. You want a solid few whacks to really seat the race.

So no tapping, hit it hard like you are trying to drive a big nail into some hardwood and use a metal hammer. It sounds like to me that you are treating it with kid gloves.

Also I will put the 2x4 in between the fork so that the 2x4 supports the crown and reaches the floor as well.

Earl Grey

Hmm. Maybe I just need to hit it harder. Maybe that's all my LBS would do anyway.

I guess worst case I am out a crown race, not a fork (I am not going to set the fork on the dropouts to do this), right?

Number400

I have a long PVC pipe and a use an old crown race as a driver and turn the whole thing upside down and give it a few hard whacks on the floor. Does the trick every time. The only trouble I have had was actually seating both the crown race AND the driver along with it. That sucked. It was a cheap fork that had a lot of height on the race and I did not even think about it before pounding it on. ^ Don't tap, give it a whack ( but not while resting on the dropouts!)

Crankycrank

Also drop the race in some boiling water before installation to expand it a bit. If you can stick the fork in the freezer for an hour or so this will help even more.

Earl Grey

So, I dropped the race in boiling water for a minute or two (by my calculations, this would only give me a few hundredths of a mm larger diameter, but that could be all the difference), set the fork back on the 2x4 and channeled a non-wimpy guy when I hit it. Looks to be seated perfectly now with no harm done to fork, steerer or race.

Thanks all!

HillRider

Glad it worked out. Yes, crown races often take a really solid whack to seat them. Too late to ask but did you grease the steerer seat area and the inside of the race itself? That makes seating easier also.

There are some headsets with a "split" crown race that easily installs with just finger pressure but they are only provided with cartridge bearing headsets where the crown "race" is just a support plate for the bottom bearing.

Earl Grey

I did grease everything liberally, yes - perhaps a bit more liberally this time (first attempt was just a thin film) and with more attention to the steerer rather than just the race.

This is actually a cartridge bearing headset, so I think the design is as you describe - the beveled inner face of the lower cartridge bearing is what contacts the crown race. Sounds like Cane Creek could use a split race (but don't)?

I do have to laugh at myself: Half an hour trawling old threads on this topic, calculating the expansion of an aluminum ring by temperature increase, measuring and re-measuring parts with a Swiss-made device accurate to a few hundredths of a millimeter...

And the solution is actually "HIT IT HARDER".

HillRider

As the maintenance guys at work used to say; "Don't force it. Use a bigger hammer."

Myosmith

Another trick is to put your fork in the freezer until it is very cold. When you are ready, warm your race by dropping it in boiling hot water for a couple of minutes. Working quickly while the fork is cold and the race is hot, tap the race firmly into place and then don't touch it while the fork and race both come to room temperature. Cooling the fork causes it to contract slightly while warming the race causes the opposite, resulting in a loose fit that will tighten up when both pieces come to a temperature in the middle. We used to do this with tight fit bearings all the time. They could be so loose they'd want to fall out, but when everything came to normal temp they'd be locked in place like they were welded.

Looigi

That's an interesting idea. Use the fork as the hammer. That way no other force is exerted on it and there's no chance of marring it. Forks can be pretty light though so it might take some doing. I'll have to try doing it that way next time it comes up.

reptilezs

best way i have found is to do it slide hammer style with the park pipe deal or flip the fork upside down and wack it on the anvil a few times

billnuke1 

In the business, we called that "mechanical agitation"! (Hit it with a hammer!").

fietsbob

set the bench vise jaws to the right gap and bang the fork and crown race on it.