Headset advice

[KM2]

Some sealed bearing headsets have a split fork column race, others a complete ring. What are the benefits of either? Is it just ease of fitment? How about solidity?
Thanks

[Gattonero]

Some sealed bearing headsets have a split fork column race, others a complete ring. What are the benefits of either? Is it just ease of fitment? How about solidity?
Thanks

Of course this type of crown race works only if the bearings are cartridge type
The benefit is easy of removal without any damage to the forks, especially full-carbon ones. It also means less chances of going seized on the forks.
They are also easy to fit without special tools, although this can potentially lead to overlook for wrong forks crown OD & facing.

Drawbacks are a potential incorrect angle for the bearing ID, should the forks not be up to standard measurement (that is easy to check), and the chance for water/dirt to seep in trough the gap (that should be facing the front, and filled with grease).
Some headset manufacturers do not use a split crown race, due to a better seal arrangement with a closed race, or because the angle to match the bearing is too shallow to allow an accurate self-centering.

[Brucey]

in theory a split crown race may move around in service if the headset preload isn't enough. In practice this doesn't seem to be a major issue; as noted above, with a split crown race you will have cartridge bearings. Once they don't have enough preload on them, they'll be on the move in all sorts of places anyway. In such headsets that have been run loose, I don't think that there was excessive wear below the crown race, although I suppose that could vary with the headset and the fork.

Overall (given that you are choosing cartridge bearings anyway, which is a whole other discussion.... ) it seems to be a design feature that doesn't do too much harm.

cheers

[Threevok]

I prefer a split race myself, as they are easier to remove, when checking the steerer and crown, or swapping forks over, but retaining the same headset

[cycleruk]

I have this type. Very easy to fit and no special tools needed.
I have had the bottom cartridge bearing affected by water so now needs a replacement.
For the moment I have just swapped over the top one to the bottom which is fine for now.
(Obviously only possible as long as they are the same size.)

[Valbrona]

The ones with the split collet are just easier to fit/remove. It's a collet, not a race. The bearing race is in the cartridge bearing.

[KM2]

Thanks for all the replies. Most helpful.