1' threadless fork - can you double check that what I am plannig makes sense?

[Ugo51]

Hi all,

I recently got a vintage-ish frame ( see here: https://www.retrobike.co.uk/threads/new-frame-new-project-touring-eg-bates-frame-531.457176/ ), which accepts 1' forks.
I think I could benefit from using a modern handlebar with 31.8mm diameter, so that it's easy to find stems of different length, but instead of using a quill stem adapter, I was thinking to use a threadless fork, and then a 25.4 to 31.8 shim on the streerer.

I never played with threadless 1' fork, but I would imagine they are the same concept at 1-1/8 forks...
The only question is, can I get a threaded fork, cut off the threded part, and plug a star nut in it? Is the inner diameter the same?
The head tube is quite short (96mm) so it's easy to find threaded forks from which I could cut off the threaded part and still have more than enough steerer left. And of course 1' threaded forks are much more common than 1' threadless.

Does all this make sense, or am I missing something?
I am a bit tight on budget and I would like to avoid buying parts just for the sake of experimenting...

Thanks!

 

[synchronicity]

You will need:
a 1" threadless headset
a 1" threadless fork
a 1" to 1.1/8" shim (these sometimes come with some older stems, or maybe someone on the forum could gift you one?)
(note that is not the same as 31.8mm, technically it is ~28.6mm. 31.8 more likely refers to the handlebar)
a 1.1/8" threadless stem

I wouldn't advise cutting a threaded fork, no.
Mainly because it should be easy enough to get the right one in the first place (threadless).

Threadless forks are often lighter as they are more likely to have an alloy or carbon steerer tube.

 

[Ugo51]

Thanks.

It's more of a light touring bike, so I am not too concerned with weight, but I will bear that in mind.

But at least in principle, I could cut a threaded fork and using it as threadless, right? The inner diameter should be the same, so I will be able to install a star nut in it?

 

[synchronicity]

I guess so. Did you have a candidate fork in mind?

But you'd have to completely cut off the threaded portion. You don't want the threads acting as little stress concentrators right below your stem, or it'll sheer off.

 

[synchronicity]

Also, remember you'll have to add the stack height of the headset and the height of the stem.
You may find that it is more steerer tube required (longer) than at first glance just by looking at the head tube?

 

[Ugo51]

Thanks.
Yes, but even with the headset, I am looking at 130-140mm needed for the steerer.

Of course, ironically, if I go with the threadless option, the streerer needs to be longer, to accomodate the stem, so I need in fact to have a longer unthread section.

I don't have a fork in mind just yet, but now that I know this much I can shop around and see what's available.

The frame has cantilever lugs, but I am still unsure whether to go canti brake or calipers.

 

[synchronicity]

Some threaded forks had a keyway (groove) or whatever it's called in them. Can't remember if they only appear on the threaded section though...


I personally wouldn't go this cutting the threaded fork route...

 

[Ugo51]

It's generally only in the threaded section, I think.

Why? What doesn't convince you of this idea?

 

[Jonny69]

Just use a quill adapter and save yourself a whole load of money and headache.

 

[Ugo51]

hehe, you speak like a reasonable person, which I am not

Headache for sure, but money not necessarily. Components are of similar price.
Of course, considering I even alrady have a quill adapter at home, it's very stubborn of me not using it...