Older headset size

[shankldu]

Any one know what ,most first gen thredless headset sizes head set sizes are ,frame n qustion is first gen Surley Crosscheck in 631 steel .

[jemdet]

What exactly is the question? Stack height? Steerer OD? Head tube ID? Crown race size?

[Mark McM]

I'm pretty sure that it will be 1 1/8". The Cross-Check came out when 1 1/8" was the most common size headset. I've got a Cross-Check from just a few years after they were introduced (I think it is first generation - its the pea green model), and it is 1 1/8".

[oliver1850]

There were 1" Cross Checks. I have a Cross Check fork on a Nishiki that is 35+ years old.

[CO_Hoya]

If you’re asking about 1” vs 1-1/8” threaded, that can be quickly assessed with a quarter, per Sheldon Brown (https://www.sheldonbrown.com/headsets.html#size).

A 1” threaded:
https://www.sheldonbrown.com/images/headset-threaded-1-small.jpg

A 1-1/8” threaded:
https://www.sheldonbrown.com/images/headset-threaded-118-small.jpg

[oliver1850]

Inspired me to measure a quarter: 24.25 mm or .954".

[GonaSovereign]

If you’re asking about 1” vs 1-1/8” threadless, that can be quickly assessed with a quarter, per Sheldon Brown (https://www.sheldonbrown.com/headsets.html#size).

A 1” threadless:
https://www.sheldonbrown.com/images/headset-threaded-1-small.jpg

A 1-1/8” threadless:
https://www.sheldonbrown.com/images/headset-threaded-118-small.jpg

Good tip, but it's for the stem quill of a threaded headset system, as shown in the photos. The hack will still work, but not quite as shown.

[CO_Hoya]

Good tip, but it's for the stem quill of a threaded headset system, as shown in the photos. The hack will still work, but not quite as shown.

Ugh, you're absolutely correct. The lesson, as always, is that I'm an idiot.

[shankldu]

I may have mispoke ,the one the pics are threadeded as far a i know mine is the strait smooth steerer , not with the nut on top. .so i ordered 1 1/8 but what came was to big ,what is the inner diameter of the head tube is what im after . Do i simpley measure across?

[Skenry]

You need to think about what you are asking and rephrase your questions a bit.

Are you asking for measurements on a headset or a stem? Threaded or threadless?

A threaded steerer tube has a stem that goes inside, so you'll need the inner measurement.
A Threadless steerer tube takes a stem that goes around the tube, so you'll need thew external measurement.

A picture might help.

[oldpotatoe]

I may have mis-spoke ,the one the pics are threaded as far a i know mine is the straight smooth steerer , not with the nut on top. .so i ordered 1 1/8 but what came was to big ,what is the inner diameter of the head tube is what i'm after . Do i simply measure across?

If 1 1/8 inch HS to too big, then yours is a '1 inch' headset. Whats' '1 inch' is the outside diameter of the steerer tube on the fork. Yours is 25.4mm(1 inch), a 1 1/8 inch fork steerer tube is 31.8mm( 1 1/8 inch).

On a steel fork steerer, the inside diameter of the fork steerer is 22.2mm(7/8inch) on a '1 inch' fork and 25.4mm(1 inch) on a '1 1/8 inch' fork.

But again, the sizes come from the OUTSIDE diameter of the fork steerer.

You need a 1 inch threadless headset....