Advice on setting crown race
 

Need advice on setting a crown race - carbon fork and steerer, 1 1/8, Chris King crown race and I'm using the Park tool. The crown race is apx. 1 mm from bottoming out and I cannot drive it down any further. I've used Tri-Flow to hopefully help, no luck. I've whacked the tool until my arm gives out, no luck. I also tried using a heat gun hoping the crown race would expand enough, no luck. However, I was reluctant to hold the heat gun on the area too long for fear of damaging the carbon.

I've seated scores of crown races, never have had one like this.

A lot of the energy from the mallet is taken up by my holding the fork. I realized I cannot rest the end of the fork on the dropouts on the floor for fear of damaging the dropouts.

I'm thinking of using a 3/4" or larger pipe, padded, to rest the fork crown on to solidly support the fork while I wack the tool. In other words, the fork would straddle the pipe which would be horizontal. But obviously this also might damaged the fork.

Advice? Suggestions?

King makes a part that you are to place on the crown race and then tap that part to avoid damaging the race. Please get that tool before you damage the crown race.

I've used a fork mount to hold the fork. I dunno if that's the right way or not.

Piece of PVC pipe. Place pipe on ground, hold fork in other end. While holding fork, tap other end of the pipe on the ground. Crown race will go right on.

Crown Race
 

You have the King adaptor for pressing crown races, correct?
If not, you can easily damage a crown race by pounding it on in the manner that you have described.
I suggest having the King tool and using grease on the inside of the race-
Then you can pound away and not worry about damage.

It may be important to think about the carbon fork, perhaps the fit is tight enough to damage the carbon?

Use something like this to secure the fork while hammering
https://deltacycle.com/bike-hitch-pro

I think it may be preferable to use headsets that have split races on carbon forks.

Sometimes the crown is to wide for the crown race. Sanding the inside of the crown race with a Dremel usually helps it fit. If it does not go on after pounding the snot out of it, then this is usually the issue. Carbon forks that do not have an aluminum sleeve moulded in to act as the crown are often slightly out of spec.

Depending on the brand, I believe some makes such as Chris King offer oversized crown races to fit such applications. It sounds like your fork was not built to spec. Did the fork previously have a crown race on it? Have you measured it with a vernier caliper? Carbon forks aren't meant to be sanded to fit and I'd be leery of that approach.

Slam harder.

I am using the correct Park tool, CRS-1, which is a drift that you hit the top with to drift down the crown race. It's the proper tool.

It's the correct race for the steerer, extremely tight fit. It was greased.

I'm wonder if I can support the fork by bracing it by the underside of the fork crown, resting it on a padded structure that would be the same shape - curve - of the fork crown. By supporting it only by holding it, no matter how firmly, isn't very effective. Too much energy is absorbed by my hand rather than going to the crown race.

hold up.
don't let the fork take the force.
i use a pvc pipe but i think the park tool works the same way. flip the entire setup upside down. then slam that puppy into your garage floor. your fork tips should be facing the ceiling while doing this.

fyi, i've set a few really tight races in the past and realized that a lot of my effort was being wasted trying not to damage the fork itself. upside down method works
and a little grease on the inside of the race always helps

King
 

Right, but King has a specific piece that fits the crown race perfectly to make sure that the race does not get damaged.
https://www.universalcycles.com/shop...s.php?id=58625

Two things - if the race won't go on as it should my money is on the fork race being too large and has a taper to it. If it went part way on and stopped it's either cocked and crocked or the fork race is too large and tapered. Try to force it on will not end well.

Secondly - do not use heat. It will make the surface if the fork gummy and give it more friction and you won't be ale to get just the headset race hot without also getting the fork hot. This will also not end well.

Take the race off, measure the fork race (or have someone with the proper tools do it) and if needed cut the race to the proper size. This has a good chance of ending well.

dave

😂💥+1

The Park tool uses 6 alloy rings to make sure the race doesn't get damaged. I doubt the King piece would make much difference in this instance.

As Mr Kirk mentioned above, stop and take a measurement of the crown race diameter of the fork. I would guess it is slightly oversize, and King ( I believe) makes over & under sized baseplates if you didn't want to mill the carbon (assuming the fork has a carbon race instead if an alloy piece). What fork are you using? Does it have an integrated bearing race already?