It's an 1 1/8" external cup according to the seller. There all kinds of conflicting info about what that means. Wondering what options I have and what I need to put a modern 31.8mm stem + bar on this bike?
If it’s really 1-1/8″ I’d spend the money to convert the headset to threadless, buy a new fork, and then run a regular stem. It will look way cleaner, the headset is probably due for new bearings anyway, and you can gain disc brakes where you need them most.
But the quill stem adapters come in both 1″ and 1-1/8″ size and work great.. I have that set up on three bikes with original forks and modern stem and handlebars. All of mine are stuck at 1″ though which is why I just keep the original forks.
Depends what you mean by modern bar. Do you mean a bar with a 31.8mm clamp diameter. You can still get new bars with 25.4 or 26mm diameters. In that case you can just use a normal quill stem like the bike would have come with originally
7 Comments
1. new fork
2. compatible threadless headset
3. stem.
[https://profile-design.com/products/threadless-converter-1?variant=1808737959962](https://profile-design.com/products/threadless-converter-1?variant=1808737959962) likely would work.
The easy answer is a [threadless quill adapter.](https://www.jbi.bike/site/product_details.php?part_number=57743) You install that, then clamp any threadless 31.8mm stem you want on to it.
Quill 25.4 (1-1/8 threaded) stems for 31.8 do exist but they’re mostly adjustable stems for comfort bikes, like [this one.](https://www.trekbikes.com/us/en_US/equipment/cycling-components/bike-stems-accessories/bike-stems/bontrager-adjustable-blendr-180mm-quill-stem/p/14351/?colorCode=black)
If it’s really 1-1/8″ I’d spend the money to convert the headset to threadless, buy a new fork, and then run a regular stem. It will look way cleaner, the headset is probably due for new bearings anyway, and you can gain disc brakes where you need them most.
But the quill stem adapters come in both 1″ and 1-1/8″ size and work great.. I have that set up on three bikes with original forks and modern stem and handlebars. All of mine are stuck at 1″ though which is why I just keep the original forks.
[Zoom Q-5 Stem Quill Adapter (1-1/8″ Threaded to 1-1/8″ Threadless) – Performance Bicycle (performancebike.com)](https://www.performancebike.com/zoom-q5-stem-quill-adapter-11-8-threaded-to-11-8-threadless-q-5/p552151)
Depends what you mean by modern bar. Do you mean a bar with a 31.8mm clamp diameter. You can still get new bars with 25.4 or 26mm diameters. In that case you can just use a normal quill stem like the bike would have come with originally
https://www.somafabshop.com/shop/nitto-stem-quill-ui12-31-8mm-2620?category=813#attr=4305,1955
Quill adapfor just make sure you get the correct top for your bars .