griffin_

whats that require? just a new stem or fork too?
or is it not doable?
this is the only part of bikes i don't really understand

dumb question?

drac_vamp

stem, fork, both to match diameter of headtube, and probably a new headtube since the headset wont fit, so probably need a whole new frame and fork and stem and bars, and at that point might as well get new wheels and seat and cranks.

spud

may as well try a different clipless system too

griffin_

all you needed to say was no
no need to be snide

drac_vamp

no, im sorry. i didnt mean to be snide, at first i thought it out, like:
"yeah, you would need a new fork and stem..." which lead me to think about the rest of it and it sort of just turned into an unintentionally snide remark. i apologize.

someone on here had it done, by bernie mickelsen frame builder extraordinaire. they used existing forks, had him replace the steerer tube. good as new i believe.

BostonFixed

Why?

puchrider137

i think the bernie mickelsen thing was on a one inch headtube of a soma if we are thinking of the same bike.

mattface 

You could. in adition to the headset and the stem you would need a new fork, because the stearer would be too short. It probably wouldn't be worthwhile if the frame had a 1 inch head tube because you wouldn't have much availability of parts, but with a 1 1/8" head tube threadless part choices are plentiful.

treechunk

the short answer is not without a new fork, as it's rather difficult to get your fork threader aligned properly on the fork without specialized tools (other than standard shop fare) Also, your star nut will prevent the installation of a standard stem, and the I.D. of the steertube is different 'cuz the wall thickness has to be greater on a threadless fork 'cuz it's gotta take all the load from the stem. I wouldn't really advse it without getting a new fork. That said, a new fork/stem/headset should take care of things provided you're going from one inch threadless to one inch threaded/ 1-1/8 threadless to 1-1/8 threaded.

Sammyboy

In addition to the headset and stem you'd need a new fork because the 1 1/8 fork wouldn't fit in the 1" headset you mean? And because none of the threaded parts would thread onto the threadless headset that was a size bigger?

yonderboy

Threaded headsets come in 1.125 varieties, but the quill stem might be harder to come by. I haven't threaded a steerer in a while, but I think there's not enough material on a threadless steerer to get a good set of threads. You could probably find a NOS fork.

They'd be big, clunky MTB-type parts, and thusly "ugz", unless you wanted to pop for a Campy or King headset.

Cynikal 

Honestly there is no good reason (except for looks) to convert from threadless to threaded. Threadless is far better and stiffer.

That being said I don't see the issue. If you are staying with the same diameter (most likely 1" )then all you need is a new stem and headset. Take the fork down to your LBS and have them thread it.

I would avoid this if you have a 1 1/8 headtube. Threaded 1 1/8 headset are hard to find as are stems.


-cheers

eddiebrannan

cynical he wants to change the other way. it's all in the thread(ed/less) title

griffin yes you can change for sure. the thing is they are fundamentally different ways of doing things.

if you currently have a threadless set-up you will need to change fork (or at least steerer but since they are attached to the fork and replacing the steerer alone usually costs more than a new fork then assume a new fork), headset and stem.

this is no big deal. the only obstacle is if your bike has a 1 1/8" headset/steerer in which case it's gonna be a big PITA, as stated above.

if it's 1" then you simply need to purchase a new fork, headset and quill stem. these will take the place of the old parts and don't require anything specific framewise (ie either set-up will work on the same frame). you can then sell the other stuff on eBay.

with threaded forks headtube length is more important than with threadless, so check with someone knowledgeable that the steerer is the correct length, since it's not simply a case of cutting any old steerer to length as with threaded.

the rest is relatively simple. as long as you have all the correct parts, you can run either set-up with ease.

i myself have the lower apparatus from a threadless headset and the uppers from a threaded, because in both cases the lower pieces, being simple bearing races, perform the same function.

the upper parts are crucial, because they compress the races and make sure that the steering pieces are attached to the steered pieces.

anyway, simple answer is yes

Cynikal 

can you convert a threadless headset to threaded?

What am I missing here?

vobopl

I have two forks for my bike - threadless chrome you coud see in the pics (FGG #2402) I have posted many times, and a threaded track fork. The lower race, top nut and cone of the threaded one fit the bits staying on the frame.

eddiebrannan

hmmm. apparently i was drunker than i thought last night.

sorry cynical

treechunk

I would be kinda careful swapping headset bits around, they tend to be just differenet enough in very tiny ways to make things difficult. You can absolutely use the whole lower assembly of a threadless headset on a threaded bike, you just need to get an appropriately matching/threaded upper assembly.

Cynikal 

No worries. You made me question my thought process more than I had in a while.

eddiebrannan

exactly what i have. lowers off a generic aheadset, uppers from a 105 threaded. threaded fork, obviously.

works, but was always a temp solution. will be switched out for campy threaded headset soon's i have some $$$

drac_vamp

maybe helping out with the OP's original question of not understanding the threadless headset would be some of some help. what about it dont you understand? i've never had a threadless headset so i don't know whats going on in them either. are you more curious about maintenance that would be needed in the future or are you just curious in general about the workings of it?

eddiebrannan

threadless headsets are composed of upper and lower bearing races. the steerer tube of the fork is a plain tube, cut to length (3mm less than the stack height of everything). there is a star-fangled nut inserted into the top of the tube. the stem is a sleeve that fits around the tube. a cap sits on the top of the tube with a bolt that passes through it and the starnut. it is wider than the stem, so as the bolt is turned it presses the cap down on to the entire assembly, compressing the races and tightening everything up (which is why the 3mm clearance). once this is done the stem bolts are tightened, so that it grips the steerer tightly.

threaded are…

oh f@ck it, over to sheldon
https://sheldonbrown.com/gloss_ha-i.html#headset

absntr

dukoshoka had it done I believe.

Bernie switched it out because threadless steerer tubes have thinner walls. Threaded steerer tubes are thicker. The torque/force/pressure/whatever is difference on a threadless vs. threaded set-up.

Enough so that Bernie deemed it necessary to hack off that steerer tube (on a Soma Rush) and replace it with thicker tubing and an already threaded steere tube to match and welded it all together. It was maybe 20 minutes of work and only $50 or so?