threadless headset and stem on threaded fork?
10-17-05, 09:15 PM
#1
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threadless headset and stem on threaded fork?
I have a threaded fork with a tube that is much longer than my headtube. The threads are about 5 inches above where the headtube ends with the fork fitted in position. I haven't purchased the headset for it yet, but, since the fork is 1" and the head tube is 1", can i just fit a threadless headset and stem for it, and just hacksaw off the threaded section?
thanks,
-Oliver
thanks,
-Oliver
10-17-05, 10:41 PM
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You can do it. Just make sure the stem doesn't clamp to any threaded section. It sounds like you'll have plenty of steer tube to avoid that. Also, make sure the star nut can fit in the inside diameter of the steerer.
Check to see if the steer has an open bottom. If not, make doubly sure about setting the star nut the correct depth.
Check to see if the steer has an open bottom. If not, make doubly sure about setting the star nut the correct depth.
10-18-05, 08:59 AM
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Shouldn't be a problem. I've done it with 1 1/8" threaded steerers and it worked fine. Just don't cut too much off the first time. You can always press the star nut further down and cut more off, but you can't add any back after it's gone.
10-18-05, 05:05 PM
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Originally Posted by BlastRadius
You can do it. Just make sure the stem doesn't clamp to any threaded section.
10-18-05, 05:12 PM
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Originally Posted by jur
Why not?
Long story short, the steerer will likely break at the threaded section so don't use it.
10-19-05, 10:15 PM
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Originally Posted by HillRider
The threads are a weak point. The metal is thinner at the bottom of the threads so the steerer tube's wall thickness is reduced. Also, the sharp angle at the thread bottom acts as a stress raiser so the steerer is more likely to break at that point. This is a problem since a threadless stem puts a bending moment on the steerer while threaded headsets and quill stems don't.
If the crown bearing on the fork is viewed as a pivot point, and the fork as the lever, the steerer tube gets a bending moment. The point where this moment is resisted, is of course at the top bearing, which is in the middle of the threaded section. So the thread is under stress, albeit from a different source as from stem. This stress may be worse than from handle bars since it has to absorb road shocks.
10-20-05, 10:54 AM
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Originally Posted by jur
The way I figure it, they do:
If the crown bearing on the fork is viewed as a pivot point, and the fork as the lever, the steerer tube gets a bending moment. The point where this moment is resisted, is of course at the top bearing, which is in the middle of the threaded section. So the thread is under stress, albeit from a different source as from stem. This stress may be worse than from handle bars since it has to absorb road shocks.
If the crown bearing on the fork is viewed as a pivot point, and the fork as the lever, the steerer tube gets a bending moment. The point where this moment is resisted, is of course at the top bearing, which is in the middle of the threaded section. So the thread is under stress, albeit from a different source as from stem. This stress may be worse than from handle bars since it has to absorb road shocks.
10-20-05, 11:44 AM
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Originally Posted by BlastRadius
You can do it. Just make sure the stem doesn't clamp to any threaded section. It sounds like you'll have plenty of steer tube to avoid that. Also, make sure the star nut can fit in the inside diameter of the steerer.
Check to see if the steer has an open bottom. If not, make doubly sure about setting the star nut the correct depth.
Check to see if the steer has an open bottom. If not, make doubly sure about setting the star nut the correct depth.
