Carbon Fork Steerer Question
#1
Senior Member
Thread Starter
Carbon Fork Steerer Question
Hi everyone,
There's a bit of play between my centerlock DT240 front hub and my front rotor, and every so often it tricks me into thinking that my headset is loose. I know it shouldn't (I even turn the front wheel sideways to check - nope, no rocking!), but it does. To confirm everything, I disassembled my front end for the first time, cleaned out the grit in there, and put a thin layer of grease on the bearing seats. When I was wiping down the steerer tube, I noticed that the carbon wasn't completely smooth and round, and that there was this 'edge' that shows up, just enough feel with my fingertips, and capture on camera (see photo below).
Am I just looking at the edge of some unfinished carbon, or is this something to be concerned about? It seems perfectly straight and even.
I reassembled the front end, preloaded the headset with my old 6-bolt rotor wheel (no rotational play in that one), and tightened my stem bolts with with my torque wrench (~5nm). This is the only thing that leaves me with a bit of a question.
Thanks everyone!
There's a bit of play between my centerlock DT240 front hub and my front rotor, and every so often it tricks me into thinking that my headset is loose. I know it shouldn't (I even turn the front wheel sideways to check - nope, no rocking!), but it does. To confirm everything, I disassembled my front end for the first time, cleaned out the grit in there, and put a thin layer of grease on the bearing seats. When I was wiping down the steerer tube, I noticed that the carbon wasn't completely smooth and round, and that there was this 'edge' that shows up, just enough feel with my fingertips, and capture on camera (see photo below).
Am I just looking at the edge of some unfinished carbon, or is this something to be concerned about? It seems perfectly straight and even.
I reassembled the front end, preloaded the headset with my old 6-bolt rotor wheel (no rotational play in that one), and tightened my stem bolts with with my torque wrench (~5nm). This is the only thing that leaves me with a bit of a question.
Thanks everyone!
#2
Full Member
Hi everyone,
There's a bit of play between my centerlock DT240 front hub and my front rotor, and every so often it tricks me into thinking that my headset is loose. I know it shouldn't (I even turn the front wheel sideways to check - nope, no rocking!), but it does. To confirm everything, I disassembled my front end for the first time, cleaned out the grit in there, and put a thin layer of grease on the bearing seats. When I was wiping down the steerer tube, I noticed that the carbon wasn't completely smooth and round, and that there was this 'edge' that shows up, just enough feel with my fingertips, and capture on camera (see photo below).
Am I just looking at the edge of some unfinished carbon, or is this something to be concerned about? It seems perfectly straight and even.
I reassembled the front end, preloaded the headset with my old 6-bolt rotor wheel (no rotational play in that one), and tightened my stem bolts with with my torque wrench (~5nm). This is the only thing that leaves me with a bit of a question.
Thanks everyone!
There's a bit of play between my centerlock DT240 front hub and my front rotor, and every so often it tricks me into thinking that my headset is loose. I know it shouldn't (I even turn the front wheel sideways to check - nope, no rocking!), but it does. To confirm everything, I disassembled my front end for the first time, cleaned out the grit in there, and put a thin layer of grease on the bearing seats. When I was wiping down the steerer tube, I noticed that the carbon wasn't completely smooth and round, and that there was this 'edge' that shows up, just enough feel with my fingertips, and capture on camera (see photo below).
Am I just looking at the edge of some unfinished carbon, or is this something to be concerned about? It seems perfectly straight and even.
I reassembled the front end, preloaded the headset with my old 6-bolt rotor wheel (no rotational play in that one), and tightened my stem bolts with with my torque wrench (~5nm). This is the only thing that leaves me with a bit of a question.
Thanks everyone!
Last edited by 13ollocks; 02-12-24 at 10:03 AM.
#3
Senior Member
Thread Starter
I’ll have to double check where the stem clamps to the steerer - I don’t remember taking note of that when I reinstalled.
If that ‘seam’ is really a compression-crushed steerer, that’s a bit of a bummer. I’ve tweaked my position a few times:
- Most of my riding has been done on a 100mm stem, with 10mm of spacers below the stem (and 10mm above)
- Swapped the 100mm for a 110mm a few rides ago, same spacer configuration
- Dropped the stem by 5mm after my last ride (15mm on top, 5mm below), and the front end play bugged me enough to disassemble and discover the irregularity.
Understanding the weaknesses of carbon steerers and that the bottom stem bolt is likely below the compression nut inside the steerer, I’ve always used a torque wrench after each adjustment, doing my best not to go past 5nm.
If that ‘seam’ is really a compression-crushed steerer, that’s a bit of a bummer. I’ve tweaked my position a few times:
- Most of my riding has been done on a 100mm stem, with 10mm of spacers below the stem (and 10mm above)
- Swapped the 100mm for a 110mm a few rides ago, same spacer configuration
- Dropped the stem by 5mm after my last ride (15mm on top, 5mm below), and the front end play bugged me enough to disassemble and discover the irregularity.
Understanding the weaknesses of carbon steerers and that the bottom stem bolt is likely below the compression nut inside the steerer, I’ve always used a torque wrench after each adjustment, doing my best not to go past 5nm.
#4
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,801
Bikes: Trek FX 2, Cannondale Synapse x2, Cannondale CAAD4, Santa Cruz Stigmata 3
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 2039 Post(s)
Liked 1,533 Times
in
1,062 Posts
I’ll have to double check where the stem clamps to the steerer - I don’t remember taking note of that when I reinstalled.
If that ‘seam’ is really a compression-crushed steerer, that’s a bit of a bummer. I’ve tweaked my position a few times:
- Most of my riding has been done on a 100mm stem, with 10mm of spacers below the stem (and 10mm above)
- Swapped the 100mm for a 110mm a few rides ago, same spacer configuration
- Dropped the stem by 5mm after my last ride (15mm on top, 5mm below), and the front end play bugged me enough to disassemble and discover the irregularity.
Understanding the weaknesses of carbon steerers and that the bottom stem bolt is likely below the compression nut inside the steerer, I’ve always used a torque wrench after each adjustment, doing my best not to go past 5nm.
If that ‘seam’ is really a compression-crushed steerer, that’s a bit of a bummer. I’ve tweaked my position a few times:
- Most of my riding has been done on a 100mm stem, with 10mm of spacers below the stem (and 10mm above)
- Swapped the 100mm for a 110mm a few rides ago, same spacer configuration
- Dropped the stem by 5mm after my last ride (15mm on top, 5mm below), and the front end play bugged me enough to disassemble and discover the irregularity.
Understanding the weaknesses of carbon steerers and that the bottom stem bolt is likely below the compression nut inside the steerer, I’ve always used a torque wrench after each adjustment, doing my best not to go past 5nm.
Many regular expander plugs are barely long enough for a regular stem (just under 40 mm height) with a 3-5 mm spacer installed above. I understand that is why excessive steerer length must be cut, i.e., to let the expander plug reach low enough within the steerer and past the lower stem bolt to properly support the stem. Having ridden mostly with a 10 mm spacer above the stem all this time, the compression force exerted by your lower stem bolt may not have been counteracted by the expander plug. Why not try a longer expansion plug? For example:
Specialized Extended Expander Plug For Carbon Steerer Tubes (1-1/8") (Alloy) - Performance Bicycle (performancebike.com)
#5
Senior Member
Join Date: Jul 2009
Posts: 6,038
Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 3998 Post(s)
Liked 7,489 Times
in
3,013 Posts
It might be that the stem twisted on the steerer, and the white line is just a little bit of resin that's been scraped off the surface.
#6
Senior Member
Thread Starter
I cannot tell from your photo whether one section of the steerer is crushed. As 13ollocks said, the glossier segment seems to be too low to correspond to your description of your stem setup.
Many regular expander plugs are barely long enough for a regular stem (just under 40 mm height) with a 3-5 mm spacer installed above. I understand that is why excessive steerer length must be cut, i.e., to let the expander plug reach low enough within the steerer and past the lower stem bolt to properly support the stem. Having ridden mostly with a 10 mm spacer above the stem all this time, the compression force exerted by your lower stem bolt may not have been counteracted by the expander plug. Why not try a longer expansion plug? For example:
Specialized Extended Expander Plug For Carbon Steerer Tubes (1-1/8") (Alloy) - Performance Bicycle (performancebike.com)
Many regular expander plugs are barely long enough for a regular stem (just under 40 mm height) with a 3-5 mm spacer installed above. I understand that is why excessive steerer length must be cut, i.e., to let the expander plug reach low enough within the steerer and past the lower stem bolt to properly support the stem. Having ridden mostly with a 10 mm spacer above the stem all this time, the compression force exerted by your lower stem bolt may not have been counteracted by the expander plug. Why not try a longer expansion plug? For example:
Specialized Extended Expander Plug For Carbon Steerer Tubes (1-1/8") (Alloy) - Performance Bicycle (performancebike.com)
I have no problem getting a longer expander plug if needed, but it sounds like the consensus here is that this probably isn't normal or just some ugly manufacturing, and I should take this bike in for evaluation. Was hoping to avoid dropping ~$1k on a new Enve fork and install - but if that's what it looks like, I'd rather that then broken teeth/collarbone/sternum etc that could come from a failure at-speed...
#7
It's carbon dontcha know.
#8
Full Member
Join Date: Jun 2020
Location: San Francisco, CA
Posts: 201
Bikes: 2018 Jamis Renegade Exploit, 1996 Trek 930, mid-90's Dean El Diente, 2010 Scott Addict SL, 1998 Trek 730, Xtracycle EdgeRunner 30D, Xtracycle Swoop, 1992 Trek 790
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked 109 Times
in
63 Posts
You want a small amount of excess height - a couple of mm - but you don't want a lot, just enough to hold a short spacer in place. You don't want the steerer to extend further beyond the headset than the maximum height the manufacturer recommends, and you usually want the expansion plug to be centered in the same area of the steerer where the stem is clamped, so unless you have a long extension on the expansion plug you're limited in how much steerer you can leave above the stem.
Likes For nathand:
#9
Senior Member
Thread Starter
I guess regardless of whether or not the shop recommends a new fork, I'll see if they have an extended expander plug - the shop I'm taking it to is (unfortunately) a Specialized and Trek shop now, so there's a chance they have what SoSmellyAir shared.
(Unfortunately because they used to carry BMC, Look, Factor, Moots, and Seven before I lived here, and now just carry the big two...)
(Unfortunately because they used to carry BMC, Look, Factor, Moots, and Seven before I lived here, and now just carry the big two...)
#10
climber has-been
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,236
Bikes: Scott Addict R1, Felt Z1
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3538 Post(s)
Liked 3,691 Times
in
1,850 Posts
Many regular expander plugs are barely long enough for a regular stem (just under 40 mm height) with a 3-5 mm spacer installed above. I understand that is why excessive steerer length must be cut, i.e., to let the expander plug reach low enough within the steerer and past the lower stem bolt to properly support the stem. Having ridden mostly with a 10 mm spacer above the stem all this time, the compression force exerted by your lower stem bolt may not have been counteracted by the expander plug. Why not try a longer expansion plug?
The compression plus was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
#11
Senior Member
Thread Starter
I have never accepted this "compression plug must be long enough to cover entire stem clamp" argument.
The compression plus was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
The compression plus was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
#12
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,801
Bikes: Trek FX 2, Cannondale Synapse x2, Cannondale CAAD4, Santa Cruz Stigmata 3
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 2039 Post(s)
Liked 1,533 Times
in
1,062 Posts
I have never accepted this "compression plug must be long enough to cover entire stem clamp" argument.
The compression plus was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
The compression plus was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
Owner's Manuals - Road (cannondale.com)
Is the 1.6 Nm for the top cap or for setting the expander plug within the steerer? The one for my Synapse is 6 Nm, and the one for my Stigmata says 8 Nm.
#13
Senior Member
Thread Starter
Took some pictures of the Lynskey after my ride today - I think I'll be taking the Bianchi out this week exclusively, at least until this gets resolved to my comfort.
Here's the bike in question: no, not quite Hot or Not material, but I think she's a decent looking bike. She's pedal-less because I figured if I was going to be taking the Bianchi out, might as well put the power meter on her for now. Note, in this picture, she only has a 5mm spacer below, and 15mm on top - a configuration I hadn't yet ridden.
For the past few years, her stem/steerer setup looked more like this, with the 10mm spacer above, and the two 5mm spacers below. This is with the 110mm stem I just put on; previously she was with a 100mm FSA stem.
Pulling that stack off, I do see the mark that was the question of the first post. I also see a similar line above. These marks roughly correspond to where the stem clamps the steerer. I will note: I can definitely feel the ridge on the lower mark, but not the top one.
The expander plug next to the steerer, and inside the stem - even without any spacers on top, the stem's bottom bolt would overhang the OEM expander.
So from the looks of it, here's my hypothesis:
1. The mark(s) on the steerer tube are caused by the stem. the upper and lower marks line up to the upper and lower clamping bolts on this stem, which is very similar to my older stem.
2. It's possible that the lower mark is more pronounced due to the lack of internal support on the steerer. As far as I recall, I've always used a torque wrench to tighten the stem, and I don't recall ever going more than a smidge past 5.5nm, and I've done my best to tighten both bolts evenly. I'm still skeptical, but there's also evidence.
I'd love to hear any other thoughts or ideas. Her front end is only lightly reassembled at this point, so pretty easy to take any additional pictures, as well. Thanks!
Here's the bike in question: no, not quite Hot or Not material, but I think she's a decent looking bike. She's pedal-less because I figured if I was going to be taking the Bianchi out, might as well put the power meter on her for now. Note, in this picture, she only has a 5mm spacer below, and 15mm on top - a configuration I hadn't yet ridden.
For the past few years, her stem/steerer setup looked more like this, with the 10mm spacer above, and the two 5mm spacers below. This is with the 110mm stem I just put on; previously she was with a 100mm FSA stem.
Pulling that stack off, I do see the mark that was the question of the first post. I also see a similar line above. These marks roughly correspond to where the stem clamps the steerer. I will note: I can definitely feel the ridge on the lower mark, but not the top one.
The expander plug next to the steerer, and inside the stem - even without any spacers on top, the stem's bottom bolt would overhang the OEM expander.
So from the looks of it, here's my hypothesis:
1. The mark(s) on the steerer tube are caused by the stem. the upper and lower marks line up to the upper and lower clamping bolts on this stem, which is very similar to my older stem.
2. It's possible that the lower mark is more pronounced due to the lack of internal support on the steerer. As far as I recall, I've always used a torque wrench to tighten the stem, and I don't recall ever going more than a smidge past 5.5nm, and I've done my best to tighten both bolts evenly. I'm still skeptical, but there's also evidence.
I'd love to hear any other thoughts or ideas. Her front end is only lightly reassembled at this point, so pretty easy to take any additional pictures, as well. Thanks!
#14
Senior Member
Thread Starter
To be honest, I don't remember where I read it. I basically took it to mean "set the expander plug only as tight as you need it to properly set your headset preload." As I had never believed that little thing was important for resisting the stem's clamping forces, that's how I did things.
#15
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,801
Bikes: Trek FX 2, Cannondale Synapse x2, Cannondale CAAD4, Santa Cruz Stigmata 3
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 2039 Post(s)
Liked 1,533 Times
in
1,062 Posts
So from the looks of it, here's my hypothesis:
1. The mark(s) on the steerer tube are caused by the stem. the upper and lower marks line up to the upper and lower clamping bolts on this stem, which is very similar to my older stem.
2. It's possible that the lower mark is more pronounced due to the lack of internal support on the steerer. As far as I recall, I've always used a torque wrench to tighten the stem, and I don't recall ever going more than a smidge past 5.5nm, and I've done my best to tighten both bolts evenly. I'm still skeptical, but there's also evidence.
1. The mark(s) on the steerer tube are caused by the stem. the upper and lower marks line up to the upper and lower clamping bolts on this stem, which is very similar to my older stem.
2. It's possible that the lower mark is more pronounced due to the lack of internal support on the steerer. As far as I recall, I've always used a torque wrench to tighten the stem, and I don't recall ever going more than a smidge past 5.5nm, and I've done my best to tighten both bolts evenly. I'm still skeptical, but there's also evidence.
#16
Senior Member
Join Date: Apr 2011
Posts: 7,301
Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4553 Post(s)
Liked 1,695 Times
in
1,113 Posts
It is worthwhile to remember that carbon fiber composites are just reinforced plastic. There is no way you can clamp metal to them and not have some compression marks. But that narrow mark on the back of the steerer is hardly anything compared to how much of a beating a carbon dropout receives:
And every carbon frame with a clamp on front derailleur has a pretty obvious crease by the clamp bolt.
And every carbon frame with a clamp on front derailleur has a pretty obvious crease by the clamp bolt.
Likes For Kontact:
#17
Senior Member
Thread Starter
Enve lists Palo Alto Bicycles as a dealer, I'll see if I can bring the bike in today. Maybe I'll be lucky and they can claim warranty or incidental damage and shave a few bucks off of a replacement. I'm pretty sure I'm no longer confident to take this bike on the Gran Fondo I'm attending in April, not with a potentially damaged steerer and -10% descents.
#18
Senior Member
Thread Starter
It is worthwhile to remember that carbon fiber composites are just reinforced plastic. There is no way you can clamp metal to them and not have some compression marks. But that narrow mark on the back of the steerer is hardly anything compared to how much of a beating a carbon dropout receives:
And every carbon frame with a clamp on front derailleur has a pretty obvious crease by the clamp bolt.
And every carbon frame with a clamp on front derailleur has a pretty obvious crease by the clamp bolt.
Definitely want to mitigate the risk of catastrophic failure, even if it means a new fork. It seems that peace of mind is worth a lot to me these days...
#19
Senior Member
Join Date: Aug 2019
Location: Québec, Canada
Posts: 2,153
Bikes: SL8 Pro, TCR beater
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 1018 Post(s)
Liked 593 Times
in
446 Posts
I have never accepted this "compression plug must be long enough to cover entire stem clamp" argument.
The compression plug was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
The compression plug was not intended to provide mechanical support for a carbon steering tube. It was intended to avoid scratching or gouging the inside of the steering tube.
Likes For eduskator:
#20
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,801
Bikes: Trek FX 2, Cannondale Synapse x2, Cannondale CAAD4, Santa Cruz Stigmata 3
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 2039 Post(s)
Liked 1,533 Times
in
1,062 Posts
Enve lists Palo Alto Bicycles as a dealer, I'll see if I can bring the bike in today. Maybe I'll be lucky and they can claim warranty or incidental damage and shave a few bucks off of a replacement. I'm pretty sure I'm no longer confident to take this bike on the Gran Fondo I'm attending in April, not with a potentially damaged steerer and -10% descents.
#21
Senior Member
Thread Starter
Now I see. It is the vertical white line (a) extending longitudinally on the surface of the steerer; and (b) coinciding with the gap of the stem at its lower bolt. It does not look that bad; how deep is that ridge?
Is this the dealer who had assembled the bike with a much too short expander plug? Otherwise, I am not sure if it would be covered under warranty. Regardless, I hope Enve extends you a significant goodwill discount toward a replacement fork, with a lecture to use a long expander plug. Good luck.
Is this the dealer who had assembled the bike with a much too short expander plug? Otherwise, I am not sure if it would be covered under warranty. Regardless, I hope Enve extends you a significant goodwill discount toward a replacement fork, with a lecture to use a long expander plug. Good luck.
The bike is a Lynskey, ordered direct from the manufacturer in summer 2019 (I think they’d gone factory direct by that point). However, PA Bikes used a similar expansion plug on the gravel bike I built up when we got out here last summer (had them cut the steerer tube and assemble the front end). I use that almost exclusively as an around-town bike (flat bars and rack mounts), so less of a concern… but I’ll check that bike too. Maybe I should order two of the long expanders before something happens to that fork - wouldn’t want to have to replace the color matched fork if I don’t need to.
I should still have the receipt for the bike purchase, but not sure if that would help much. Lynskey was back ordered on their own forks, so I was given the Enve as a no-cost upgrade for them to get the bike out the door. Not sure it’s actually listed anywhere on the digital receipt. We’ll see after work.
#22
don't try this at home.
Join Date: Jan 2006
Location: N. KY
Posts: 5,974
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 987 Post(s)
Liked 528 Times
in
363 Posts
The "vertical white line" --- is it the green scrape marks, or the purple line?
That purple line looks like an edge of the carbon wrap, very normal.
~~~
The scrape marks don't seem to match up with the shape of the stem clamp. Is there a sharp, vertical internal edge on the inside of the stem clamp?
That purple line looks like an edge of the carbon wrap, very normal.
~~~
The scrape marks don't seem to match up with the shape of the stem clamp. Is there a sharp, vertical internal edge on the inside of the stem clamp?
#23
don't try this at home.
Join Date: Jan 2006
Location: N. KY
Posts: 5,974
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 987 Post(s)
Liked 528 Times
in
363 Posts
Around 2014, there was a page on BianchiUSA.com, about steerer damage from incorrectly installed stems. It appears to be gone from the internet, but a couple of the images are in this old post I did:
https://www.bikeforums.net/21006763-post22.html
There's a "not damaged" photo, and a "steerer tube damaged" one, and an extremely crushed image, too.
~~~
Steerers are quite strong. Even the short, cutoff end after I shortened my steerer was sturdy.
I wouldn't worry about surface damage, but I'd be concerned about crushing extending farther into the layers, especially if it's been ridden at lot over rough surfaces with an incorrectly tightened stem. I could expect the damage to get worse over time.
Those green arrow scrapes seem to be on the surface?
https://www.bikeforums.net/21006763-post22.html
There's a "not damaged" photo, and a "steerer tube damaged" one, and an extremely crushed image, too.
~~~
Steerers are quite strong. Even the short, cutoff end after I shortened my steerer was sturdy.
I wouldn't worry about surface damage, but I'd be concerned about crushing extending farther into the layers, especially if it's been ridden at lot over rough surfaces with an incorrectly tightened stem. I could expect the damage to get worse over time.
Those green arrow scrapes seem to be on the surface?
#24
climber has-been
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,236
Bikes: Scott Addict R1, Felt Z1
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3538 Post(s)
Liked 3,691 Times
in
1,850 Posts
The whole "compression plugs protect fragile carbon steering tubes from being crushed by mean old stem clamps" story was something people made up, long after compression plugs were introduced. I haven't seen any analysis to back up this claim, and I've been looking for at least 10 years. The story has the sound of bike mechanic scuttlebutt -- plausible sounding, but with no engineering to support it.
Likes For terrymorse:
#25
Senior Member
Thread Starter
Around 2014, there was a page on BianchiUSA.com, about steerer damage from incorrectly installed stems. It appears to be gone from the internet, but a couple of the images are in this old post I did:
https://www.bikeforums.net/21006763-post22.html
There's a "not damaged" photo, and a "steerer tube damaged" one, and an extremely crushed image, too.
~~~
Steerers are quite strong. Even the short, cutoff end after I shortened my steerer was sturdy.
I wouldn't worry about surface damage, but I'd be concerned about crushing extending farther into the layers, especially if it's been ridden at lot over rough surfaces with an incorrectly tightened stem. I could expect the damage to get worse over time.
Those green arrow scrapes seem to be on the surface?
https://www.bikeforums.net/21006763-post22.html
There's a "not damaged" photo, and a "steerer tube damaged" one, and an extremely crushed image, too.
~~~
Steerers are quite strong. Even the short, cutoff end after I shortened my steerer was sturdy.
I wouldn't worry about surface damage, but I'd be concerned about crushing extending farther into the layers, especially if it's been ridden at lot over rough surfaces with an incorrectly tightened stem. I could expect the damage to get worse over time.
Those green arrow scrapes seem to be on the surface?
This particular stem is new to the bike, as I decided to go a little more stretched out and aero. More saddle time in CA means more flexibility, and the 100mm stem was starting to feel a little cramped. I'll take a picture of the old stem when I go out to the garage later. Not exactly the same, but still a two bolt clamp with opposed bolts.
The frame and fork have just over 5.1k miles on them (about 1.6k between July and Dec of last year). Definitely getting a lot of use recently.