lineinthewater

So, it's my understanding that the top of a road fork usually resembles this (complete flat where it meets the steerer):

https://www.sjscycles.com/supersize/26862.jpg

I am trying to replace the headset on my Cannondale slice fork. The old system is a loose bearing headset. Below the bottom race, on top of the fork, is a silver metal cap. The new (sealed) headset appears to want to drop flat onto the fork, but the cap is preventing that. Is the cap part of the fork? Or is it stuck/fused to the fork? I've tried to lightly pry it up, but so far it won't budge. I don't want to force it without some advice.

FBinNY 

I assume you have a threadless headset. The normal arrangement is a plain unthreaded steerer that ends short of the top of the stem and spacer stack by 2-3mm so that the top cap can push down on the stack to compress the headset. Since nothing ever touches the actual end of the fork, it doesn't need a perfect cut.

If your fork came with a top cap, you need to remove it to install. Here are pictures of typical headset parts in sequence you can use for guidance, but if you've never done this there are plenty of tutorials available. Search "installing bicycle headset" to find them and review a few until the light goes on.

lineinthewater

Your link goes to the wikipedia on Butyl rubber. lol

Yes, it sounds like the top cap needs to be removed. It's below the crown race.

FBinNY 

I fixed the link, but I'm confused. How on earth is it possible for the top cap to be below the crown race? Check the updated link, review some tutorials and make sure you understand how this works before going farther.

lineinthewater

My terminology is off. I should take a pic. I have removed the fork from the frame. I have removed all the bearings. All that remains is the fork, and what appears to be a piece of metal (that the crown race was previously on top of). The metal piece appears to be stuck to the fork, unless I'm totally wrong and it's actually part of the fork.

It appears it is a two-part crown race - with the part that rides on the bearings separate from the part that mates to the fork. Is this correct? The new headset appears to have one piece that both rides on the bearing AND mates to a FLAT fork surface.

FBinNY 

Yes, there's a crown race seat, which is usually (but not always) one with the fork. Crown race is a press fit onto the seat.

While that is the normal system, there are variations. For example some sealed bearing headsets don't use a press on crown race, but instead have a split cone, which engages the lower bearing race and compresses onto the fork, the same way the top centering cone does.

If you're unsure, a photo will help, but you should be able to dope it out if you review a few tutorials.

JohnDThompson 

Pictures would be extremely helpful. Failing that, take the fork to your LBS for them to sort out.

lineinthewater

Yes, thank you for naming it - crown race seat. Should I have purchased the exact same loose-bearing headset model, so as to not have to replace/remove the crown race seat?

lineinthewater

Working on it. One minute.

lineinthewater

Here we go:

https://i241.photobucket.com/albums/f...Water/fork.jpg

striknein

That's the crown race. It most likely needs to be removed and replaced with the one provided with your new headset.

lineinthewater

How do I make sure it is removable before proceeding? Is there a special tool to do it, or do you have to just pry it up?

striknein

There is a special puller that is made to remove the crown race without dinging up the fork. Given the oversized fork crown, you'll have a difficult time removing it using brute force. I'd recommend taking it to your LBS.

FBinNY 

READ SOME TUTORIALS until you understand the whole picture. Doing it piecemeal this way, by asking questions, can get you into trouble, because you have no of knowing what you don't know.

lineinthewater

I don't understand how I'm doing it piecemeal? I have a very specific question, with a specific picture. I understood how it all went together BEFORE I posted this thread, as I had replaced the (loose) ball bearings several times. My terminology may have been off, and you may have misinterpreted my problem because of it, but the issue is very specific (and has been since the beginning of this thread): does the crown race seat come off my fork? If so, how?

FBinNY 

I see. You posted the second photo after we started the dialog. Yes, the crown does come off, and lucky for you you can het under the edge to get it started. Improvise a mini crow bar and pry it up by degrees, until you can set a punch behind it off and tap it up the rest of the way.

There is a tool made for the job, but it's very pricey ($100+). But most shops have the tool, so if you're afraid of maring the seat area on the fork, you can let a shop do it. Should cost $10.00 or less.

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lineinthewater

Thanks for following up with detailed info. How can you tell this crown race seat is actually removable (for my education)?

Does the new crown race seat (for the new headset) need a special tool to press it onto the fork?

FBinNY 

The crown race seat is the part of the fork that the race presses onto. The seat is the precise diameter base of the steerer, usually about 5/16" tall, and the machined flat area the crown race bottoms to. The crown race itself is the hardened steel bottom race of the headset, and specific to each headset.

As I posted earlier, sealed bearing headsets don't use a crown race per se, since that's part of the bearing. Instead they have a locating cone, that has to be pressed on just like a regular race would be. However since it isn't actually part of the bearing, some makers capitalize on that and make a split one, that works the same way as the centering cone at the top of a threadless headset.