Why can't I get a good threadless headset adjustment using a threaded fork!!????
07-24-08, 11:50 PM
#1
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Why can't I get a good threadless headset adjustment using a threaded fork!!????
So, I have been trying to use a threadless headset on a threaded fork to no avail. I can't get a good adjustment on the headset! I tried two different headsets, two different threaded forks - no good!!!
Then I tried to a threadless fork, just to check, and hey presto, no problems; headset adjusted perfectly!
Can anyone explain this strange phenomenon???
Then I tried to a threadless fork, just to check, and hey presto, no problems; headset adjusted perfectly!
Can anyone explain this strange phenomenon???
07-25-08, 12:50 AM
#2
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The threaded fork isn't long enough by a long shot to stick up high enough to make this work. Are you trying to use collars on the thread to set the bearing preload? And then use a quill stem?
If so then I can think of a number of things that would be a deal stopper on this idea. The first is that when you thread the steerer the threaded portion is actually enough smaller than 1 1/8 to likely not work with the split wedging ring and upper bearing. Or perhaps something esle would jump out at me if I could see it in person.
If so then I can think of a number of things that would be a deal stopper on this idea. The first is that when you thread the steerer the threaded portion is actually enough smaller than 1 1/8 to likely not work with the split wedging ring and upper bearing. Or perhaps something esle would jump out at me if I could see it in person.
07-25-08, 09:16 AM
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The threaded fork isn't long enough by a long shot to stick up high enough to make this work. Are you trying to use collars on the thread to set the bearing preload? And then use a quill stem?
If so then I can think of a number of things that would be a deal stopper on this idea. The first is that when you thread the steerer the threaded portion is actually enough smaller than 1 1/8 to likely not work with the split wedging ring and upper bearing. Or perhaps something esle would jump out at me if I could see it in person.
If so then I can think of a number of things that would be a deal stopper on this idea. The first is that when you thread the steerer the threaded portion is actually enough smaller than 1 1/8 to likely not work with the split wedging ring and upper bearing. Or perhaps something esle would jump out at me if I could see it in person.
Yes! I think you have hit the nail on the head. I was thinking there may be a slight discrepancy in diameter between the threadless steerer and the threaded part of the threaded steerer. I did have the stem clamped to the threaded section (and yes, I know this is not good practice for safety concerns), so the slight diameter difference may have been enough for a poor interface between these parts. FYI,
I was trying to set the headset and stem up the same as for a standard threadless headset; i.e. - race, wedge ring, spacers, stem, top cap.
Thanks.
07-25-08, 11:39 AM
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Out of curiosity.....why even try this exercise in aggravation with parts that a not designed to work together?
07-25-08, 11:50 AM
#6
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Also what happens is the threads bite into the stem and creates some depressions. This prevents you from loosening the stem and sliding it a small amount to make bearing-preload adjustments, it just wants to migrate back to the old position into the thread grooves. The only way to adjust in micro-increments is to rotate the stem, like the adjustable-cup in the threaded-headsets. However, you can't exactly ride your bike with the stem aimed sideways at 90-degrees. But hey, the headset is adjusted perfectly! 
07-25-08, 12:20 PM
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Also what happens is the threads bite into the stem and creates some depressions. This prevents you from loosening the stem and sliding it a small amount to make bearing-preload adjustments, it just wants to migrate back to the old position into the thread grooves. The only way to adjust in micro-increments is to rotate the stem, like the adjustable-cup in the threaded-headsets. However, you can't exactly ride your bike with the stem aimed sideways at 90-degrees. But hey, the headset is adjusted perfectly!
07-25-08, 12:21 PM
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07-25-08, 01:39 PM
#9
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A new fork would be by far the best plan of action.
With the threaded fork and the stem clamped to the threaded area you've also got a serious stress point at the base of the stem clamping area. The threads cut into the steer tube and create a strong stress riser point. With a surprisingly light force compared to a non threaded steer tube you will be able to bust that threaded tube much like the "Tear Along The Dotted Line" of forms.
Save yourself a potential accident and get the right item. Threaded steer tubes were never intended to withstand back and forth rocking loads such as you see at the base of the stem's clamping area.
With the threaded fork and the stem clamped to the threaded area you've also got a serious stress point at the base of the stem clamping area. The threads cut into the steer tube and create a strong stress riser point. With a surprisingly light force compared to a non threaded steer tube you will be able to bust that threaded tube much like the "Tear Along The Dotted Line" of forms.
Save yourself a potential accident and get the right item. Threaded steer tubes were never intended to withstand back and forth rocking loads such as you see at the base of the stem's clamping area.
07-27-08, 08:47 AM
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07-27-08, 09:28 AM
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So basically. I'm trying to use the wrong type of headset, with the wrong fork and it doesn't work.
Holy cow!
Holy cow!
