threaded fork to threadless?
 

I do mostly resto/retro mod builds and I love a threadless fork/ clamp on stem set up.

What are people's opinions on using larger threaded *steel* steer tube forks, cutting off the threaded portion and using it as a threadless fork with a star nut on a smaller frame where there is enough space to fully clamp a stem on?

I'm not talking about aluminum steer tubes or clamping anything onto the threaded portion of a fork.

I have two projects right now where this is a possibility for me, but I've read mixed things online regarding the practice. Is the steel typically too thin if it's not designed as a threadless fork or is this totally fine?

If thats not too convoluted to follow, let me know what you think. Thanks!

Star nut is fine but a compression plug is easier.

I think threaded 1" steerers have a thicker wall vs. threadless, so it should be safe at least. The fit of the star nut and getting a clean cut on a steel steerer are what I would be concerned about.

You're fine, steel threaded steerers are all strong enough to be threadless, once you cut off the threaded top. If there's some exception to that rule that I'm not thinking of, someone here will fill us in.

In the "oversize" (now normal) 9/8" threadless steerers, you used to be able to get a lightweight version that was thinner wall (and maybe you still can). They were based on the idea that a threaded steerer needs to be thicker, threadless can get away with being thinner. That's why you shouldn't assume you can go the other way, as in putting a quill stem in a threadless steerer. If the steerer is the lightweight thinner-wall type, then the inside diameter is too large to fit a quill stem. Not that this comes up very often, no one wants to do that!

I've done it several times on 1" forks. Same star nut goes in fine. And you can always thread it in the future.

Thank you guys, this was just the info I was looking for. Mainly that it would be thick enough steer tube to still be safe for use. I guess I will go ahead with the first project which is a Trek 720 (multitrack) to drop bar (and now threadless!) conversion

Now that you publicly announced your project, please post pictures. Trek 700 series bikes are sometimes overlooked as good starting points for gravel and road bikes.

celesteguy What's wrong with a quill adaptor?

It's not always the most elegant solution but it gives the connivence of a threadless stem setup without the expense of buying a second fork. Plus if the next owner wants a quill stem he doesn't have to change the fork.

I slipped a section of black hose over this to make the quill adapter seem thinker and more proportional to the stem, bars and frame tubes
https://scontent-ord5-2.xx.fbcdn.net...dw&oe=697D7107

I used something like this

https://encrypted-tbn1.gstatic.com/s...o82_BDKEOz5XUg

Quill adaptors work great, unless the fork you wanting to use has an extra long steer tube. I’ve been considering this for a new build. The fork is from a 24” frame with a really long steer tube.

If you cut off the threaded portion, wouldn't the steerer be too short to reach the top bearing? Or are you talking about cutting the steerer short and then using a quill to threadless adapter?

I've used quill adaptors or bought threadless forks to do restomods. I prefer to use original fork, headset and quill stem, but that's just a looks preference.
If I had to replace a missing or damaged fork I would go threadless, but if I'm buying a threadless headset I would go on the hunt for a threadless carbon fork. Not as easy to find in 1 inch but are out there.
That said I don't see any issues with using a cut down threaded fork or even clamped onto threads.

I believe the OP is talking about buying a new fork, but a much longer one for the bike,

I have never understood the appeal of the threadless setup and fail to see any real benefit. I want to be able to raise or lower my handlebars, so I am sticking with good old stems and threaded forks.

John E The only advantage I ever saw was cost savings for bike and component manufacturers. You don't need thread a fork or headset anymore.

Threadless setups have a great deal of adjustability. That includes a wide range of angles, to changing height along the steerer by shuffling around spacers and the stem itself, to the various lengths available. In terms of angles, here's what Tree Fort Bikes offers (https://www.treefortbikes.com/cat/1519/Stems):

• -10 Deg
• -12 Deg
• -15 Deg
• -16 Deg
• -17 Deg
• -18 Deg
• -20 Deg
• -25 Deg
• -5 Deg
• -6 Deg
• -7 Deg
• -8 Deg
• 0 Deg
• 10 Deg
• 12 Deg
• 15 Deg
• 16 Deg
• 17 Deg
• 25 Deg
• 3 Deg
• 30 Deg
• 35 Deg
• 45 Deg
• 5 Deg
• 6 Deg
• 7 Deg
• 77 Deg
• 8 Deg
• Adjustable

And lengths/reach:

• 100mm
• 105mm
• 110mm
• 120mm
• 125mm
• 130mm
• 135mm
• 140mm
• 150mm
• 155mm
• 200mm
• 30mm
• 32mm
• 33mm
• 35mm
• 38mm
• 40mm
• 42.5mm
• 42mm
• 43mm
• 45mm
• 46mm
• 48mm
• 50mm
• 51mm
• 53mm
• 55mm
• 60mm
• 65mm
• 70mm
• 75mm
• 80mm
• 90mm
• 95mm

There's also the Innicycle headset. I wouldn't cut off the threaded part of the steer tube, just because I'm paranoid about the front end of my bikes, and the Voices would never shut up about it.

Plus, 1" threadless stems aren't common, and they were all like 2,173 mm long and -13.7 pi semi-demi-radian angled 1995 Fred-bait anyway, so there's actually negative reasons to do it.

--Shannon

Hmm, makes me wonder what you think can go wrong. OP is talking about a steerer that's way too long, so even after cutting the threads off he still has enough steerer for the stem to clamp to. Seems safe to me.

Any 9/8" stem will clamp to an inch steerer with a shim.

You can raise your handlebars by moving the spacers, flipping the stem, etc. You can also adjust your headset and replace the stem entirely with just allen wrenches.


And it is lighter.

I mean, you're a framebuilder, and I shouldn't be trusted with more heat than a lighter, so yeah. On the other hand, after all these years, I know what The Voices are going to say... we finish each other's sentences and everything! And on the gripping hand, one of the reasons that I fell in love with the bicycle, (as the French and Italians say,) is that, while it doesn't shut them up, they tend to say more pleasant things when I'm riding. I'd hate to screw that up.

I'd forgotten about that. And I've shimmed handlebars, although I prefer not to if I don't have to.

--Shannon

And one quill stem replaces all of the above because with the quill stem you just need to loosen one bolt and raise and lower it.

How does that change the angle of the quill? Maybe I’m just geometry challenged.

You can replace a quill with different angles like you can replace a threadless with different angles. There is no functional difference between flipping a threadless stem and raising a quill stem - both keep the same distance from the steerer axis.

Sure, and my point is that there are lots more angles available in threadless stems.

Rule Number One !
Rational, data loaded posts will gain you no traction on this forum. No matter what the topic. Ever.


​​​​​Rule Number Two
Some posters may actually be stoopid and not just pretending. Facts have absolutely no effect on them. See Rule Number One.

The reason to have different angle threadless stems, is so you can adjust the height of the bar, right? With a quill stem, you can adjust the height by loosening one screw and raising and lowering the stem.

Ah, yes, of course. The limit there is how long/high your stem is and do you need a Technomic to get your bars level with your saddle (which I do). My larger point is to respond to the often-expressed thought in this forum that older is better/simpler. When it comes to stem height and angles, I don't think that's true.

And you just continue to get sucked in. It's getting difficult for me to feel sorry for you. :foo:

Best to direct your sorrow elsewhere! My expectations for reasonable, informed debate on the internets are quite low.

The angle itself has no function. As long as you can locate the bar where you want it, the way you get there is immaterial.

Aren’t you contradicting yourself with those two sentences? The stem angle allows you to “locate the bar where you want it.” I’d call that a “function.”