hhk25

I changed forks on a bike recently and on the new fork, the crown race (from the old fork) slipped into place on the steerer tube without much effort. In other words, I pushed it down by hand instead of using the crown race setting tool. There didn't appear to be any perceptible movement in the race but I'm wondering if I should be concerned about this. Every other crown race I've installed was a tight fight and had to be tapped down using the tool.

Maybe I'm worried about nothing and the compression from the top cap will tighten up the race? Or should I be looking to replace the race?

bboy314

Are the forks both milled for the same size crown race? If it’s a 1” steer tube, you might be switching from a 27mm to 26.4mm race seat, in which case I’d replace the crown race with the proper size. Or if it’s a 1 1/8” steer tube, is the new crown race the split type? These are made to slide on without a tool.

HillRider

Was the fit of the crown race on the new steerer a modestly firm push fit or sloppy fit? If it took a reasonably firm push you should be fine. If it was a 27.0 race on a 26.4 steerer the fit would be noticeably sloppy. As to a split crown race, the OP just transferred the old race to the new fork so that isn't the issue unless the old race was already a split type.

hhk25

Using digital calipers, the old fork is 30.08mm. The new fork (I have a second uninstalled, identical fork) measures about the same. Give or take .02mm. I’m assuming any difference is just error created by how hard I push the calipers jaws.

I think I’m okay. What’s the worst that can happen? Damage the race and bearings?

Andrew R Stewart 

I suspect (from what the OP says) that both forks were machined for the same crown race diameter fit but the replacement fork was cut a tad too small. (This is not uncommon with hand driven machining).

Two options are dimpling the crown race diameter with a center punch in a number of spots around the steerer and/or using a retaining compound (LockTite 609 or equivalent). Andy

hhk25

Modestly firm and the race was not the split type.

JohnDThompson 

A bearing retaining compound, as Andrew suggests above, would work. E.g. Loctite #609. Stein makes a knurling tool to slightly increase the diameter of the race seat to fix this issue, as well. Probably not cost-effective for a one-off job, but perhaps a local shop may already have one and do the work for you?


https://steintool.com/portfolio-items/knurling-tool/

Crankycrank

Check with the headset mfr. I know Chris King sold slightly undersized races for their HS but you had to contact them directly to get the info. and possibly the same for other mfrs.