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Cracked nut
I am pretty much a know-nothing when it comes to bike mechanics can change wheels and adjust brakes/derailleurs but that is about it, noticed a crack today on a nut on my steerer (?) is this the sort of job you could tackle yourself (although not experienced with bike mechanics I am not handless) or do I let the LBS replace it? All advice welcome, if this is a non-event type job and I should tackle it myself could someone give me a step by step account of how to change it or a link to a page where this is discussed. Pic of crack/nut etc at :- http://www.sidtech.co.uk/iu/soup86307461862.JPG -- yours S Nihil curo de ista tua stulta superstitione |
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#2
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soup popped their head over the parapet saw what was going on and said
I am pretty much a know-nothing when it comes to bike mechanics can change wheels and adjust brakes/derailleurs but that is about it, noticed a crack today on a nut on my steerer (?) is this the sort of job you could tackle yourself (although not experienced with bike mechanics I am not handless) or do I let the LBS replace it? All advice welcome, if this is a non-event type job and I should tackle it myself could someone give me a step by step account of how to change it or a link to a page where this is discussed. Pic of crack/nut etc at :- http://www.sidtech.co.uk/iu/soup86307461862.JPG Wish I wasn't in a such a hurry to post all the time the allen bolt running through it just needed a wee bit gentle persuasion (involving a hammer and a block of wood), this meant the entire handlebar assembly can be removed and the locking (?) nut at the top of the headset can be removed now to go to the LBS to see if they stock a replacement for this nut :- http://www.sidtech.co.uk/iu/soup87404839307.JPG is this a "common" spare part as I feel buying an entire head set just to replace this part is beyond the pale. -- yours S Nihil curo de ista tua stulta superstitione |
#3
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On Wed, 11 May 2005 14:22:51 GMT, "soup"
wrote: I am pretty much a know-nothing when it comes to bike mechanics can change wheels and adjust brakes/derailleurs but that is about it, noticed a crack today on a nut on my steerer (?) is this the sort of job you could tackle yourself (although not experienced with bike mechanics I am not handless) or do I let the LBS replace it? All advice welcome, if this is a non-event type job and I should tackle it myself could someone give me a step by step account of how to change it or a link to a page where this is discussed. Pic of crack/nut etc at :- http://www.sidtech.co.uk/iu/soup86307461862.JPG Read this first: http://sheldonbrown.com/handsup.html (That's basically background about stems in general, but it's worth reading since it explains how the stem mounting works.) The job is easy. Mark the current installed depth of the stem using some tape or nail polish or whatever you've got that will work. Loosen the bolt in the middle of the stem a couple of turns (it's the one that has the hex recess, right in the top of the vertical part of the stem) and give it a smack straight down with a hammer or wrench; this should make the stem and handlebars suddenly able to move without turning the fork[1]. Pull the handlebar and stem assembly out of the steerer tube. If the wire for the computer isn't long enough to allow this, just undo the comp's bracket for now, letting it dangle, and put it back on when you're done. At this point, you can just unscrew the cracked nut and take it along to the bike ship to get a replacement. If they're nice people, they might scrounge one from the used parts pile and sell it to you cheap; if they don't keep a used parts pile (or they're Profit Maximization Oriented) they may tell you that the only way they can sell you one is as part of a complete headset; it's up to you to decide if that's a ripoff or not. Having secured a new nut by whatever means, it just gets run down against the stuff that's below it and tightened firmly in place. Huge amounts of torque are not required. If everything's OK, there should be no play in the steering bearing but you should be able to move the fork freely with essentially no resistance. (A slight feeling of non-smoothness is normal; these are generally not high-precision bearings.) If there's drag, undo the nut a turn and unscrew the round knurled part (below the nut) until there's no drag and just a teensy bit of play, and then retighten the nut and check for play. Readjust as needed so that when the nut is tight, there is neither slack nor drag in the bearing. If there's play in the headset bearing when the nut's tight (and there probably will be until you adjust it, if that nut's been cracked for very long), you'll need to screw that knurled round part (it's actually part of the upper bearing) down a bit to take the slack out of the bearing before tightening the nut. It is not uncommon to need to leave just a tiny bit of slack in the bearing before you tighten the nut in order to have no slack and no drag when the nut is tight. Once you're happy with the adjustment of the headset with the nut back on tight, slip the stem back into the steerer to the same depth that it was before (you marked it, right?), snug the stem bolt a bit, check the centering of the bars vs the front wheel, and when it looks right, tighten the bolt to lock the bars in place. Recheck it after the first couple of rides if you're not sure that you got it tight enough. [1] If the bolt drops down flush when struck, but the stem is still pretty much locked in place, unscrew the bolt a few more turns and smack it again. That should get the stem loose. -- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts. |
#4
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Werehatrack popped their head over the parapet saw what was going on
and said On Wed, 11 May 2005 14:22:51 GMT, "soup" wrote: I am pretty much a know-nothing when it comes to bike mechanics can change wheels and adjust brakes/derailleurs but that is about it, noticed a crack today on a nut on my steerer (?) is this the sort of job you could tackle yourself (although not experienced with bike mechanics I am not handless) or do I let the LBS replace it? All advice welcome, if this is a non-event type job and I should tackle it myself could someone give me a step by step account of how to change it or a link to a page where this is discussed. Pic of crack/nut etc at :- http://www.sidtech.co.uk/iu/soup86307461862.JPG Read this first: http://sheldonbrown.com/handsup.html (That's basically background about stems in general, but it's worth reading since it explains how the stem mounting works.) The job is easy. Mark the current installed depth of the stem using some tape or nail polish or whatever you've got that will work. Loosen the bolt in the middle of the stem a couple of turns (it's the one that has the hex recess, right in the top of the vertical part of the stem) and give it a smack straight down with a hammer or wrench; this should make the stem and handlebars suddenly able to move without turning the fork[1]. Pull the handlebar and stem assembly out of the steerer tube. If the wire for the computer isn't long enough to allow this, just undo the comp's bracket for now, letting it dangle, and put it back on when you're done. At this point, you can just unscrew the cracked nut and take it along to the bike ship to get a replacement. If they're nice people, they might scrounge one from the used parts pile and sell it to you cheap; if they don't keep a used parts pile (or they're Profit Maximization Oriented) they may tell you that the only way they can sell you one is as part of a complete headset; it's up to you to decide if that's a ripoff or not. Having secured a new nut by whatever means, it just gets run down against the stuff that's below it and tightened firmly in place. Huge amounts of torque are not required. If everything's OK, there should be no play in the steering bearing but you should be able to move the fork freely with essentially no resistance. (A slight feeling of non-smoothness is normal; these are generally not high-precision bearings.) If there's drag, undo the nut a turn and unscrew the round knurled part (below the nut) until there's no drag and just a teensy bit of play, and then retighten the nut and check for play. Readjust as needed so that when the nut is tight, there is neither slack nor drag in the bearing. If there's play in the headset bearing when the nut's tight (and there probably will be until you adjust it, if that nut's been cracked for very long), you'll need to screw that knurled round part (it's actually part of the upper bearing) down a bit to take the slack out of the bearing before tightening the nut. It is not uncommon to need to leave just a tiny bit of slack in the bearing before you tighten the nut in order to have no slack and no drag when the nut is tight. Once you're happy with the adjustment of the headset with the nut back on tight, slip the stem back into the steerer to the same depth that it was before (you marked it, right?), snug the stem bolt a bit, check the centering of the bars vs the front wheel, and when it looks right, tighten the bolt to lock the bars in place. Recheck it after the first couple of rides if you're not sure that you got it tight enough. [1] If the bolt drops down flush when struck, but the stem is still pretty much locked in place, unscrew the bolt a few more turns and smack it again. That should get the stem loose. Thanks V-much Werehatrack first part of your post was what I did now to see if "Freewheelin'" in Edinburgh are nice people or profit maximise orientated if they are charging the earth there is allways EBC who might have a spare nut. Aside :- Does anyone have any recomendations for 'bike shops in Edinburgh preferably in the west but anywhere really. -- yours S Nihil curo de ista tua stulta superstitione |
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#7
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Bill Sornson popped their head over the parapet saw what was going on
Coke can head tube? Nah a walking (?) advert for CC, actually had wheel discs at the back emblazoned with the CC logo and coloured red and white ,this bike was actually a competition win and appears to be made of (V-heavy) cheese and as such don't want to spend much money on it at all. http://www.sidtech.co.uk/iu/soup415049140.JPG -- yours S Nihil curo de ista tua stulta superstitione |
#8
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soup wrote:
Bill Sornson popped their head over the parapet saw what was going on Coke can head tube? Nah a walking (?) advert for CC, actually had wheel discs at the back emblazoned with the CC logo and coloured red and white ,this bike was actually a competition win and appears to be made of (V-heavy) cheese and as such don't want to spend much money on it at all. http://www.sidtech.co.uk/iu/soup415049140.JPG Holy crap that's a death trap! Happy Riding |
#9
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Bill Sornson popped their head over the parapet saw what was going on
and said Holy crap that's a death trap! Happy Riding Thanks for your good wishes. -- yours S Nihil curo de ista tua stulta superstitione |
#10
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soup wrote:
I am pretty much a know-nothing when it comes to bike mechanics can change wheels and adjust brakes/derailleurs but that is about it, noticed a crack today on a nut on my steerer (?) is this the sort of job you could tackle yourself (although not experienced with bike mechanics I am not handless) or do I let the LBS replace it? All advice welcome, if this is a non-event type job and I should tackle it myself could someone give me a step by step account of how to change it or a link to a page where this is discussed. Pic of crack/nut etc at :- http://www.sidtech.co.uk/iu/soup86307461862.JPG That's a trivially simple thing if you have suitable tools. Get a new locknut at your LBS. They'll range $2 to $10 depending on quality, finish and brand - any BSC locknut will fit. Remove the stem, unscrew broken nut, lubricate thread, fasten new nut. Reinstall your stem with lubricated threads and wedge, then check the bearing adjustment. Apply the front brake with one hand and rock the bike front to back. With your other hand, grasp the headset so your fingers are touching both the adjustable race (the knurled part) and the cup (smooth black part) just below it. If there's play, unscrew the locknut, turn the adjusting race tighter and repeat. Once there's no play, lift the bike by holding the top tube just behind the headset and turn the handlebars/fork slowly side to side. There should be no more resistance than when it was loose -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971 |
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