Is my carbon fork steerer tube damaged by overtightened stem bolts












5















As per the title: I've had my bike serviced by a bike shop, who helpfully tightened up the stem cap and pinch bolts on my headset. I rode it approx 15 km (9 miles) and I noticed some play in the headset was reintroduced. I went through the usual steps of tightening it again (loosening off the pinch bolts, then checking wheel/bar alignment, then tightening the cap bolt, then re-tightening the pinch bolts), however I noticed the ridiculous amount of tightening on the pinch bolts. So much so, I could barely remove the bolts and nearly rounded them off.



I'm concerned that there's some damage to the steerer tube, as the pinch bolts were only rated to 5NM and they were clearly much tighter than that, and the play in the headset had returned in a short distance. Attached are some photos of the tube, where I can't see any obvious cracks, but you can see where the stem has been tightly mounted. (The top section that is dark, with an oval imprint, is where the stem has been mounted very tightly).



enter image description here



Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride?










share|improve this question

























  • Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride? Would you trust whatever answer they gave you?

    – Andrew Henle
    Jan 28 at 0:21











  • Do you have another LBS in range, for a second opinion?

    – Criggie
    Jan 28 at 6:52
















5















As per the title: I've had my bike serviced by a bike shop, who helpfully tightened up the stem cap and pinch bolts on my headset. I rode it approx 15 km (9 miles) and I noticed some play in the headset was reintroduced. I went through the usual steps of tightening it again (loosening off the pinch bolts, then checking wheel/bar alignment, then tightening the cap bolt, then re-tightening the pinch bolts), however I noticed the ridiculous amount of tightening on the pinch bolts. So much so, I could barely remove the bolts and nearly rounded them off.



I'm concerned that there's some damage to the steerer tube, as the pinch bolts were only rated to 5NM and they were clearly much tighter than that, and the play in the headset had returned in a short distance. Attached are some photos of the tube, where I can't see any obvious cracks, but you can see where the stem has been tightly mounted. (The top section that is dark, with an oval imprint, is where the stem has been mounted very tightly).



enter image description here



Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride?










share|improve this question

























  • Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride? Would you trust whatever answer they gave you?

    – Andrew Henle
    Jan 28 at 0:21











  • Do you have another LBS in range, for a second opinion?

    – Criggie
    Jan 28 at 6:52














5












5








5








As per the title: I've had my bike serviced by a bike shop, who helpfully tightened up the stem cap and pinch bolts on my headset. I rode it approx 15 km (9 miles) and I noticed some play in the headset was reintroduced. I went through the usual steps of tightening it again (loosening off the pinch bolts, then checking wheel/bar alignment, then tightening the cap bolt, then re-tightening the pinch bolts), however I noticed the ridiculous amount of tightening on the pinch bolts. So much so, I could barely remove the bolts and nearly rounded them off.



I'm concerned that there's some damage to the steerer tube, as the pinch bolts were only rated to 5NM and they were clearly much tighter than that, and the play in the headset had returned in a short distance. Attached are some photos of the tube, where I can't see any obvious cracks, but you can see where the stem has been tightly mounted. (The top section that is dark, with an oval imprint, is where the stem has been mounted very tightly).



enter image description here



Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride?










share|improve this question
















As per the title: I've had my bike serviced by a bike shop, who helpfully tightened up the stem cap and pinch bolts on my headset. I rode it approx 15 km (9 miles) and I noticed some play in the headset was reintroduced. I went through the usual steps of tightening it again (loosening off the pinch bolts, then checking wheel/bar alignment, then tightening the cap bolt, then re-tightening the pinch bolts), however I noticed the ridiculous amount of tightening on the pinch bolts. So much so, I could barely remove the bolts and nearly rounded them off.



I'm concerned that there's some damage to the steerer tube, as the pinch bolts were only rated to 5NM and they were clearly much tighter than that, and the play in the headset had returned in a short distance. Attached are some photos of the tube, where I can't see any obvious cracks, but you can see where the stem has been tightly mounted. (The top section that is dark, with an oval imprint, is where the stem has been mounted very tightly).



enter image description here



Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride?







headset stem steerer bolt






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Jan 28 at 6:51









Criggie

43.3k573148




43.3k573148










asked Jan 27 at 21:16









tomandcotomandco

497




497













  • Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride? Would you trust whatever answer they gave you?

    – Andrew Henle
    Jan 28 at 0:21











  • Do you have another LBS in range, for a second opinion?

    – Criggie
    Jan 28 at 6:52



















  • Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride? Would you trust whatever answer they gave you?

    – Andrew Henle
    Jan 28 at 0:21











  • Do you have another LBS in range, for a second opinion?

    – Criggie
    Jan 28 at 6:52

















Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride? Would you trust whatever answer they gave you?

– Andrew Henle
Jan 28 at 0:21





Without returning to the shop that bungled the job, is there a way to tell if this is safe to ride? Would you trust whatever answer they gave you?

– Andrew Henle
Jan 28 at 0:21













Do you have another LBS in range, for a second opinion?

– Criggie
Jan 28 at 6:52





Do you have another LBS in range, for a second opinion?

– Criggie
Jan 28 at 6:52










2 Answers
2






active

oldest

votes


















8














In practical terms, it's impossible to tell for sure in a case like this. It's probably fine, but there's no way of knowing absolutely via visual inspection.



The surface indentations from the stem windows do occur naturally even with consistently correct torque on the fasteners. They're pretty normal to see.



It would be a good idea to get it as clean as possible so it can inspected closely for cracks or delamination. If you find any of that, it's toast.






share|improve this answer
























  • They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

    – Carel
    Jan 29 at 18:43



















0














Simplfied, Carbon Fibre is strands embedded in a cured resin. That oval looks like a mark on the outer layer of resin, and not a cut through to any of the fibres below. Try running your fingernail over the edges and lines, and see how deep any damage is.



Get a second opinion from someone else in person. Remember your worst case here is a new fork, and the bike is okay to keep riding.



Then if it seems appropriate, seal up the area with a very thin coat of resin, or clear nail varnish (Do consult others for ideas here.) This slight increase in thickness will help.



Finally when you do reassemble, use carbon fibre assembly paste, even if your stem is something else. This will help increase friction between stem and steerer, and you won't need as much tension.



If that doesn't help, then its possible your stem is slightly distorted and not able to clamp down enough. I've managed to successfully file a small amount off an aluminium stem to make it pinch up better, but not if its made of carbon fibre. CF-wrapped aluminium could be filed okay.



Another option is to move a spacer from below to above the stem, making it clamp down on a slightly different area of the spacer.





Separately - if the LBS has damaged your bike then you may have a legal claim against them for poor work. This is totally dependent on your location in the world and the laws in that place.



For me I know I have to give them the opportunity to "make right" but I could insist that someone else works on the bike, not the original mechanic.



This section really is more of a law.SE question.






share|improve this answer



















  • 2





    Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

    – Adam Rice
    Jan 28 at 19:41











Your Answer








StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "126"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fbicycles.stackexchange.com%2fquestions%2f59073%2fis-my-carbon-fork-steerer-tube-damaged-by-overtightened-stem-bolts%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









8














In practical terms, it's impossible to tell for sure in a case like this. It's probably fine, but there's no way of knowing absolutely via visual inspection.



The surface indentations from the stem windows do occur naturally even with consistently correct torque on the fasteners. They're pretty normal to see.



It would be a good idea to get it as clean as possible so it can inspected closely for cracks or delamination. If you find any of that, it's toast.






share|improve this answer
























  • They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

    – Carel
    Jan 29 at 18:43
















8














In practical terms, it's impossible to tell for sure in a case like this. It's probably fine, but there's no way of knowing absolutely via visual inspection.



The surface indentations from the stem windows do occur naturally even with consistently correct torque on the fasteners. They're pretty normal to see.



It would be a good idea to get it as clean as possible so it can inspected closely for cracks or delamination. If you find any of that, it's toast.






share|improve this answer
























  • They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

    – Carel
    Jan 29 at 18:43














8












8








8







In practical terms, it's impossible to tell for sure in a case like this. It's probably fine, but there's no way of knowing absolutely via visual inspection.



The surface indentations from the stem windows do occur naturally even with consistently correct torque on the fasteners. They're pretty normal to see.



It would be a good idea to get it as clean as possible so it can inspected closely for cracks or delamination. If you find any of that, it's toast.






share|improve this answer













In practical terms, it's impossible to tell for sure in a case like this. It's probably fine, but there's no way of knowing absolutely via visual inspection.



The surface indentations from the stem windows do occur naturally even with consistently correct torque on the fasteners. They're pretty normal to see.



It would be a good idea to get it as clean as possible so it can inspected closely for cracks or delamination. If you find any of that, it's toast.







share|improve this answer












share|improve this answer



share|improve this answer










answered Jan 27 at 22:19









Nathan KnutsonNathan Knutson

23.6k12060




23.6k12060













  • They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

    – Carel
    Jan 29 at 18:43



















  • They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

    – Carel
    Jan 29 at 18:43

















They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

– Carel
Jan 29 at 18:43





They might also be deposits of grime or even the slightest indentation visually enhanced by such deposit. On the other hand, the sturdy metal expansion inset in the steerer tube will counter compression from the outside. Even to the degree of shearing off the bolt-heads on the stem.

– Carel
Jan 29 at 18:43











0














Simplfied, Carbon Fibre is strands embedded in a cured resin. That oval looks like a mark on the outer layer of resin, and not a cut through to any of the fibres below. Try running your fingernail over the edges and lines, and see how deep any damage is.



Get a second opinion from someone else in person. Remember your worst case here is a new fork, and the bike is okay to keep riding.



Then if it seems appropriate, seal up the area with a very thin coat of resin, or clear nail varnish (Do consult others for ideas here.) This slight increase in thickness will help.



Finally when you do reassemble, use carbon fibre assembly paste, even if your stem is something else. This will help increase friction between stem and steerer, and you won't need as much tension.



If that doesn't help, then its possible your stem is slightly distorted and not able to clamp down enough. I've managed to successfully file a small amount off an aluminium stem to make it pinch up better, but not if its made of carbon fibre. CF-wrapped aluminium could be filed okay.



Another option is to move a spacer from below to above the stem, making it clamp down on a slightly different area of the spacer.





Separately - if the LBS has damaged your bike then you may have a legal claim against them for poor work. This is totally dependent on your location in the world and the laws in that place.



For me I know I have to give them the opportunity to "make right" but I could insist that someone else works on the bike, not the original mechanic.



This section really is more of a law.SE question.






share|improve this answer



















  • 2





    Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

    – Adam Rice
    Jan 28 at 19:41
















0














Simplfied, Carbon Fibre is strands embedded in a cured resin. That oval looks like a mark on the outer layer of resin, and not a cut through to any of the fibres below. Try running your fingernail over the edges and lines, and see how deep any damage is.



Get a second opinion from someone else in person. Remember your worst case here is a new fork, and the bike is okay to keep riding.



Then if it seems appropriate, seal up the area with a very thin coat of resin, or clear nail varnish (Do consult others for ideas here.) This slight increase in thickness will help.



Finally when you do reassemble, use carbon fibre assembly paste, even if your stem is something else. This will help increase friction between stem and steerer, and you won't need as much tension.



If that doesn't help, then its possible your stem is slightly distorted and not able to clamp down enough. I've managed to successfully file a small amount off an aluminium stem to make it pinch up better, but not if its made of carbon fibre. CF-wrapped aluminium could be filed okay.



Another option is to move a spacer from below to above the stem, making it clamp down on a slightly different area of the spacer.





Separately - if the LBS has damaged your bike then you may have a legal claim against them for poor work. This is totally dependent on your location in the world and the laws in that place.



For me I know I have to give them the opportunity to "make right" but I could insist that someone else works on the bike, not the original mechanic.



This section really is more of a law.SE question.






share|improve this answer



















  • 2





    Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

    – Adam Rice
    Jan 28 at 19:41














0












0








0







Simplfied, Carbon Fibre is strands embedded in a cured resin. That oval looks like a mark on the outer layer of resin, and not a cut through to any of the fibres below. Try running your fingernail over the edges and lines, and see how deep any damage is.



Get a second opinion from someone else in person. Remember your worst case here is a new fork, and the bike is okay to keep riding.



Then if it seems appropriate, seal up the area with a very thin coat of resin, or clear nail varnish (Do consult others for ideas here.) This slight increase in thickness will help.



Finally when you do reassemble, use carbon fibre assembly paste, even if your stem is something else. This will help increase friction between stem and steerer, and you won't need as much tension.



If that doesn't help, then its possible your stem is slightly distorted and not able to clamp down enough. I've managed to successfully file a small amount off an aluminium stem to make it pinch up better, but not if its made of carbon fibre. CF-wrapped aluminium could be filed okay.



Another option is to move a spacer from below to above the stem, making it clamp down on a slightly different area of the spacer.





Separately - if the LBS has damaged your bike then you may have a legal claim against them for poor work. This is totally dependent on your location in the world and the laws in that place.



For me I know I have to give them the opportunity to "make right" but I could insist that someone else works on the bike, not the original mechanic.



This section really is more of a law.SE question.






share|improve this answer













Simplfied, Carbon Fibre is strands embedded in a cured resin. That oval looks like a mark on the outer layer of resin, and not a cut through to any of the fibres below. Try running your fingernail over the edges and lines, and see how deep any damage is.



Get a second opinion from someone else in person. Remember your worst case here is a new fork, and the bike is okay to keep riding.



Then if it seems appropriate, seal up the area with a very thin coat of resin, or clear nail varnish (Do consult others for ideas here.) This slight increase in thickness will help.



Finally when you do reassemble, use carbon fibre assembly paste, even if your stem is something else. This will help increase friction between stem and steerer, and you won't need as much tension.



If that doesn't help, then its possible your stem is slightly distorted and not able to clamp down enough. I've managed to successfully file a small amount off an aluminium stem to make it pinch up better, but not if its made of carbon fibre. CF-wrapped aluminium could be filed okay.



Another option is to move a spacer from below to above the stem, making it clamp down on a slightly different area of the spacer.





Separately - if the LBS has damaged your bike then you may have a legal claim against them for poor work. This is totally dependent on your location in the world and the laws in that place.



For me I know I have to give them the opportunity to "make right" but I could insist that someone else works on the bike, not the original mechanic.



This section really is more of a law.SE question.







share|improve this answer












share|improve this answer



share|improve this answer










answered Jan 28 at 7:01









CriggieCriggie

43.3k573148




43.3k573148








  • 2





    Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

    – Adam Rice
    Jan 28 at 19:41














  • 2





    Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

    – Adam Rice
    Jan 28 at 19:41








2




2





Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

– Adam Rice
Jan 28 at 19:41





Agree with all this. Also, with carbon steerers, it's a good idea to have a solid "bung" in the steerer tube to support the tube when the stem is clamped down on it. A lot of these bungs are cut down (or omitted) in the interest of weight savings, but this situation illustrates why that might be a false economy.

– Adam Rice
Jan 28 at 19:41


















draft saved

draft discarded




















































Thanks for contributing an answer to Bicycles Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fbicycles.stackexchange.com%2fquestions%2f59073%2fis-my-carbon-fork-steerer-tube-damaged-by-overtightened-stem-bolts%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Biblatex bibliography style without URLs when DOI exists (in Overleaf with Zotero bibliography)

ComboBox Display Member on multiple fields

Is it possible to collect Nectar points via Trainline?