What’s the best headset system?

I’m building a custom frame for XC/marathon purposes but can’t decide between integrated, semi-integrated, external or whatever

I’m after reliability and aestethics here

The two most long-lived headsets on my bikes are a standard 1 1/8 external (probably not an option on most modern bikes) and the external 44mm headset on my Surly Krampus.

Integrated headset on my 2017 DMR Trailstar generally only lasts a couple of years tops.

If I was getting a frame built I’d go for a 44mm head tube. Means you can fit any type of steerer tube and fit angle-sets, etc.

yes 44mm but semi-integrated ?

Is it a tapered steerer, 44mm would mean semi integrated top and external bottom or both semi integrated for a straight steerer.

When I got a custom frame I went 44mm headtube with tapered steerer.

Aheadset style with external cups and caged balls, nver had any problems with them on any of my bikes Road, hardtail MTB, FS MTB, MTB tandem, in 25 years. I tried a cartridge bearing headset from a well known UK manufacturer once that is how many rides it lasted.

yes 44mm but semi-integrated ?

Actually, yes, I think it’s external bottom, but semi top.

Old style coventional headsets, they last(ed) forever –
like https://www.chainreactioncycles.com/hope-conventional-ec34-headset/rp-prod19877
And the Syncros one in my singlespeed.
Definitely not integrated!

It’s normally the sealing, or lack of, that kills a headset, not the size or style.

Take the TH-073E bearing found in the bottom of a lot of FSA headsets. Each cartridge bearing has two faces that need sealing where there is relative movement between the two races. In this particular bearing, 9ne of these has no attempt at sealing or shielding. If there’s no lip seal between the cup and the crown race, it’s just asking for trouble.

Fully integrated removes the option to add an angleset later. Semi integrated and external are essentially the same concept packaged differently and both work. I’d go for a 44mm straight headtube with, for a tapered steerer, a semi integrated top cup and external bottom. It looks neatest and gives you more options in future if standards change.

Find the one that will allow you to use double sealed cartridges for the size you are looking, so work backwards from the best bearing that fits your steerer.