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#1
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Threadless headset on (unthreaded bit of) threaded steerer?
If you had a 1" threaded fork which had too short a threaded bit for your
headset, could you fit a 1" threadless headset on it? Or is 1" the outside diameter of the threads, leaving the unthreaded bit too small? Or is it like tyres where one 20" is totally different from another 20"? |
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#2
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Threadless headset on (unthreaded bit of) threaded steerer?
Alan Braggins wrote:
If you had a 1" threaded fork which had too short a threaded bit for your headset, could you fit a 1" threadless headset on it? Or is 1" the outside diameter of the threads, leaving the unthreaded bit too small? Or is it like tyres where one 20" is totally different from another 20"? It would be unlikely that the threads would stand proud of the diameter of the tube - not practical to make stuff that way (not impossible, just a pointless effort unless there's a specific engineering reason to do so), so the outside diameter of the thread is very probably the same as that of the tube itself. -- Wally www.wally.myby.co.uk http://iott.melodolic.com |
#3
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Threadless headset on (unthreaded bit of) threaded steerer?
Alan Braggins wrote:
If you had a 1" threaded fork which had too short a threaded bit for your headset, could you fit a 1" threadless headset on it? Or is 1" the outside diameter of the threads, leaving the unthreaded bit too small? Or is it like tyres where one 20" is totally different from another 20"? No, this doesn't work. Shimano 105 headsets don't last very long, but they have an unusually low stack height of 32mm and might solve your problem. You could also buy a new carbon fork (£60-ish) or get a longer steerer brazed into your existing one, if it's steel and has a cast fork crown (similar price). |
#4
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Threadless headset on (unthreaded bit of) threaded steerer?
Alan Braggins wrote:
If you had a 1" threaded fork which had too short a threaded bit for your headset, could you fit a 1" threadless headset on it? Or is 1" the outside diameter of the threads, leaving the unthreaded bit too small? Or is it like tyres where one 20" is totally different from another 20"? No, the diameters of the unthreaded bits are the same and you can do what you're thinking of. Only potential dodginess is when any of the portion of the tube that the stem clamps to is threaded, as the threads can act as a stress riser, causing it to snap! ~PB |
#5
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Threadless headset on (unthreaded bit of) threaded steerer?
Pete Biggs wrote:
Only potential dodginess is when any of the portion of the tube that the stem clamps to is threaded, as the threads can act as a stress riser, causing it to snap! Precisely. And this will be the case if it's already too short for a threaded headset. |
#6
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Threadless headset on (unthreaded bit of) threaded steerer?
Wally wrote:
Alan Braggins wrote: If you had a 1" threaded fork which had too short a threaded bit for your headset, could you fit a 1" threadless headset on it? Or is 1" the outside diameter of the threads, leaving the unthreaded bit too small? Or is it like tyres where one 20" is totally different from another 20"? It would be unlikely that the threads would stand proud of the diameter of the tube - not practical to make stuff that way (not impossible, just a pointless effort unless there's a specific engineering reason to do so), so the outside diameter of the thread is very probably the same as that of the tube itself. Almost any bolt will have rolled threads which have a greater diameter than the base shank. Steerer tubes have cut threads, but that is a historical necessity and pretty rare. So the answer is correct, but no marks as the reasoning is totally off -- --- Marten Gerritsen INFOapestaartjeM-GINEERINGpuntNL www.m-gineering.nl |
#7
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Threadless headset on (unthreaded bit of) threaded steerer?
Zog The Undeniable wrote:
No, this doesn't work. Shimano 105 headsets don't last very long, but they have an unusually low stack height of 32mm and might solve your problem. You could also buy a new carbon fork (£60-ish) or get a longer steerer brazed into your existing one, if it's steel and has a cast fork crown (similar price). I beg to differ. This depends largely upon the circumstances. Hooves 1 used a threadless headset on a threaded steerer (for engineering reasons) and the only minor problem was getting the headset components over the unthreaded portion of the steerer (Which was slightly greater than 1" diameter!). If the stem is only clamping a over half or less it's length then you are perhaps onto dodgy ground, but careful selection of a stem can solve this. Because of the threading, I would suggest buying a 1 1/8" stem and shim (Often included for free) as this will put some extra material in over the threading and perhaps prevent damage to the stem itself. Zog is right in that it may well be easier to buy a new fork. Jon |
#8
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Threadless headset on (unthreaded bit of) threaded steerer?
Zog The Undeniable wrote:
Pete Biggs wrote: Only potential dodginess is when any of the portion of the tube that the stem clamps to is threaded, as the threads can act as a stress riser, causing it to snap! Precisely. And this will be the case if it's already too short for a threaded headset. Not necessarily. If the threaded section is not long enough, but the steerer is excessively long (e.g. cut and threaded for a long head tube, and used on a short head tube) it is possible for the steerer to be long enough to be used in a threadless setup. In this case it is also possible to have your friendly frame builder cut the threads further for you, although depending on the steerer in question that may or may not be advisable. Jon |
#9
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Threadless headset on (unthreaded bit of) threaded steerer?
M-gineering wrote:
Almost any bolt will have rolled threads which have a greater diameter than the base shank. The pile of M6 capscrews next to my little mill have threads that aren't proud of the shanks. Steerer tubes have cut threads, but that is a historical necessity and pretty rare. The question was *about* threaded steerer tubes and the diameters concerned. So the answer is correct, but no marks as the reasoning is totally off Your 'critique' is irrelevant - bolts with rolled threads was not under discussion. -- Wally www.wally.myby.co.uk http://iott.melodolic.com |
#10
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Threadless headset on (unthreaded bit of) threaded steerer?
In article , Pete Biggs wrote:
Alan Braggins wrote: If you had a 1" threaded fork which had too short a threaded bit for your headset, could you fit a 1" threadless headset on it? Or is 1" the outside diameter of the threads, leaving the unthreaded bit too small? Or is it like tyres where one 20" is totally different from another 20"? No, the diameters of the unthreaded bits are the same and you can do what you're thinking of. I'm an idiot. Somehow I completely forgot what a fork thread looks like, and misinterpreted a photo as having a smooth top and threaded lower part, which would need the thread larger than the upper part. I'm not sure how I managed that, apart from concentrating more on the tests I was running than the browsing and posting while waiting for them. But it isn't, it's a cut thread in a fixed diameter tube, starting at the top, and it will be long enough, I think. So, the next question is, does anyone know of a 1" equivalent of DAHONSTAJ118 on http://www.gaerlan.com/dahon/upgrade/stem.htm ? |
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