1 inch threadless headset with 27mm crown race

[jimbog]

Hi all, just wanted to put an issue out there for comment. I am building a 94 Serotta ATX with a 1 inch steerer tube. I sourced a rigid fork that I would like to use but as usual there’s a hick up. I bought a cane creek threadless headset which came with a 26.4mm crown race. I assumed that this would fit the fork but it appears to have a JIS 27mm crown. I am searching for a 1 inch threadless headset with a 27mm crown race but most have 26.4mm.
I assume that such a thing exists and has anybody got a recommendation? I think the one below may come with two sizes crown races but no websites seem to confirm this. Ignore the 1/18th on the pic, it’s the description below that makes me think that it will come with both crown race sizes.

 

[jimbog]

With a bit more googling I am pretty sure this one come with both crown races so I have purchased one.

 

[Rod_Saetan]

It does! You can always asks a bike shop to cut the crown down to 26.4 too - though not a lot of shops will have the top these days.

 

[jimbog]

It does! You can always asks a bike shop to cut the crown down to 26.4 too - though not a lot of shops will have the top these days.

Found it hard enough to find a bike shop with a steerer thread cutter a while ago, let alone this! Though it easier just to replace the headset

 

[Rod_Saetan]

This just popped up on Instagram:

View this content on Instagram

View this content on Instagram

27.0 / JIS crown race for King headsets.

 

[jimbog]

Thanks for this. Hopefully what I have ordered will have the JIS race included. Fingers crossed

 

[otherself]

Sounds like your fork is of Asian origin, therefore JIS fit 27.0 crown race (Japanese Industrial Standard). European forks were 26.4 (campag).

Here’s a 1 inch threadless A-headset with menu to select a 27.0 crown race
https://woodmancomponents.com/products/woodman-axis-lt-r-1-theadless-headset

 

[pwebb]

You are more likely to find a 1" threaded headset with the requisite 27.0 mm crown race , which you can then re-used with your thread less headset. 1" thread less is quite rare as most went 1 1/8 . The m part headsets often come with both, as you have found but do cost a lot. Look at 'bankrupt bike parts' store on eBay or their www website as they stock cost effective retro headsets both threaded and thread less. Individual crown races tend to be as expensive as a whole headset.
There are ali-express cheap headsets with 27.0 but may take a few weeks to arrive at this time of year. I keep a few of those for spares for exactly the reason you are experiencing. The vast majority of retro steel forks are 27.0 mm in my experience but unfortunately a large proportion of headsets on sale come with 26.4