herbarium

I have a very nice American Classic 1 inch Threadless headset (like pictured) that is missing it's matching crown race. I have tried to find a matching crown race without any luck.

Is it possible to use the headset without a crown race??

For example, the bottom bearing would rest on the fork? I remember while searching for a low stack headsets some people opted not to use a the top bearing seal, where the stem or spacers rested directly onto of the sealed bearings. I am wondering if it is possible to do the same with the bottom?

The headset has sealed bearing and the fork is a 1 inch carbon fork with a carbon steerer and blades bonded to an aluminum crown.

3alarmer 

...you can install it that way, but it will not work very well, nor will it last very long. The lower bearing assembly requires the crown race to function properly.

HillRider

A few forks have the crown race machined into and integral with the base of the steerer but I have to assume yours doesn't. The American Classic web site no longer shows any headsets but they do have a "contact us" link and maybe they can help you. Otherwise, I'd give up on that headset and buy a good replacement. Cane Creek still lists a 1" cartridge bearing headset in their "40" series and these are very good and reasonably priced.

CliffordK

I suppose the first question is how snugly does the bearing cartridge fit onto the fork? If it fits well, then you may be OK.

If not, then NO.

Many of the sealed threadless headsets have a split ring somewhat like this, but unfortunately finding one in 1" could be a hassle.

easyupbug 

If an odd bearing it is difficult, but worth a look at the bearings that came with the headset and get the angle of the taper printed on the side of the bearing, I have been lucky to find another maker with an available split crown race with the same angle, the seal was not too good but with the sealed cartridge bearings it is doing just fine. Good luck.

dsaul

I don't know if the bearing angle is the same, but this Cane Creek crown race would be better than not using one. https://www.amazon.com/Cane-Creek-40...138635&sr=8-28

herbarium

Thanks all, I'll try to reach out to American Classic, but chances look slim.

Another thing I am wondering is if the bearing is a standard size and it could fit a crown race like the Crane Creek listed? Which I assume is for standard bearings.

Finally, I could simply mix and match the top and bottom of the headset. For example, have the American Classic top, but use a different bottom, since any 1" bottom cup and matching race would do. As seen here: https://sheldonbrown.com/headsets.html#mix

3alarmer 

...IIRC (and I might not), your AC headset has sealed bearing cartridges. The crown race for a sealed bearing is significantly different in shape and function from a regular loose or caged bearing crown race. In fact, even though it's called a "crown race", a sealed bearing crown race does not act as a bearing race at all. It's a support for the lower cartridge.

I have encountered one bicycle where someone installed a sealed bearing headset using the old fork race. I guess he couldn't get the old one off and figured they all work the same. It worked well enough for the guy who installed it, I guess. Which was not very well. What happens is you can't really get a good, tight adjustment. The resulting steering play gives you pretty inexact steering of your bicycle.