Integrated seat post normal wear?
#1
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
Integrated seat post normal wear?
Bought this frame last year and rode it for the summer/fall. It had some cosmetic damage to the paint/decal where the previous owner mounted the mast. I'm taller so I used spacers and touched up the area with some white paint to make it look a little less noticeable.
I bought a new bike and am attempting to sell this one. I've taken pictures of the area and one ebayer sent me a message that cracked paint like that is a sign of serious damage an imminent failure.
I think he's just being obnoxious as I had my LBS look at it when I bought it and they said its normal. I've looked at it very closely and can't see any damage or cracks in the carbon, it's just the paint/decal wearing off from the seat mast clamp. In the top pic you can even see where the paint or decal is starting to do that where I've mounted the mast. Note: I do use a torque wrench to tighten it to the proper setting.
Does anyone have experience with these frames? Is this normal or potentially a problem?

I bought a new bike and am attempting to sell this one. I've taken pictures of the area and one ebayer sent me a message that cracked paint like that is a sign of serious damage an imminent failure.
I think he's just being obnoxious as I had my LBS look at it when I bought it and they said its normal. I've looked at it very closely and can't see any damage or cracks in the carbon, it's just the paint/decal wearing off from the seat mast clamp. In the top pic you can even see where the paint or decal is starting to do that where I've mounted the mast. Note: I do use a torque wrench to tighten it to the proper setting.
Does anyone have experience with these frames? Is this normal or potentially a problem?

Last edited by Gus90; 01-18-15 at 08:39 PM.
#2
Senior Member
Joined: Feb 2014
Posts: 1,538
Likes: 2
From: Cabot, Arkansas
Bikes: Lynskey Twisted Helix Di2 Ti, 1987 Orbea steel single speed/fixie, Orbea Avant M30, Trek Fuel EX9.8 29, Trek Madone 5 series, Specialized Epic Carbon Comp 29er, Trek 7.1F
That's not the type of paint damage you would typically see from flexing. I would guess it was caused by an improvised repair stand that wasn't padded enough. Doesn't look like an issue to me but it doesn't make selling it any easier.
#3
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
Some of the paint or decal where I have the post mounted now is starting to do the same already. Perhaps it's due to an uneven cut when the post was cut down that allows for a tiny bit of rocking of the mast. If that's the case I sure hope it's not leading to a potential problem. I don't want to cut it any more since I'm trying to sell it. But you are correct in that it's making a sale a little harder. The frame is like new other than that, so frustrating. I'm beginning to think I'll never buy an ISP frame again.
#4
Senior Member
Joined: Feb 2014
Posts: 1,538
Likes: 2
From: Cabot, Arkansas
Bikes: Lynskey Twisted Helix Di2 Ti, 1987 Orbea steel single speed/fixie, Orbea Avant M30, Trek Fuel EX9.8 29, Trek Madone 5 series, Specialized Epic Carbon Comp 29er, Trek 7.1F
You could always do some light sanding to smooth the edges out then find a little touch up paint that matches better. Since it isn't damaged your not trying to hide anything.
#8
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
I don't see anything wrong with asking opinions on a bike forum especially since others may have the same model and can tell me their experience with that type of wear. I'm sure you get that right?
#9
Senior Member


Joined: Jan 2009
Posts: 4,437
Likes: 1,698
From: San Diego, CA
I did, as I mentioned in the original post. My LBS is a high end shop as well as an authorized Giant retailer.
I don't see anything wrong with asking opinions on a bike forum especially since others may have the same model and can tell me their experience with that type of wear. I'm sure you get that right?
I don't see anything wrong with asking opinions on a bike forum especially since others may have the same model and can tell me their experience with that type of wear. I'm sure you get that right?
#10
Banned
Joined: Jun 2010
Posts: 43,586
Likes: 1,380
From: NW,Oregon Coast
Bikes: 8
Any How.. Sell , only to a buyer with shorter legs who can cut off some..
or Beef Up the inside of the post with More epoxy saturated CF cloth and Use the inflation of an Inner tube to press out the air bubbles ..
while the epoxy is Curing..
IMO. just like doing Fiberglassing just cloth and resins are different..
or Beef Up the inside of the post with More epoxy saturated CF cloth and Use the inflation of an Inner tube to press out the air bubbles ..
while the epoxy is Curing..
IMO. just like doing Fiberglassing just cloth and resins are different..
Last edited by fietsbob; 01-19-15 at 02:34 PM.
#11
I would not take a chance on buying that frame, no matter how the seller described it. Too many ham-fisted owners over-tightening CF for me to trust something like that as cosmetic, rather than structural, especially concerning the seat mast in particular.
That said, I'd inspect by sound -- rap the carbon lightly with the handle end of a screwdriver along the seat mast. If it sounds different, more a dead *thunk* than a sharp *knock*, near the crack, frame would be suspect...
That said, I'd inspect by sound -- rap the carbon lightly with the handle end of a screwdriver along the seat mast. If it sounds different, more a dead *thunk* than a sharp *knock*, near the crack, frame would be suspect...
#12
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
The trouble with many shop mechanics is that they are not necessarily experts on CF construction or damage. I'm no expert and to me the photo appears to be only superficial but I think I would be hesitant to buy that frame or allow someone's who's safety I value to take a ride on it on the chance that I'm completely wrong, a possibility. I think it would be best to find some type of CF repair or fabricator shop and take it to them and get some kind of written validation even if you have to pay for it. They don't have to be bike specific just someone who is a true expert on CF.
update: There's a LBS near me that repairs Carbon Fiber, I contacted them with some photos and they said it looks like it's just cosmetic but bring it in and they'll inspect it. Either way they said they can fix it up and it shouldn't be too expensive.
Last edited by Gus90; 01-19-15 at 03:59 PM.
#13
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
I would not take a chance on buying that frame, no matter how the seller described it. Too many ham-fisted owners over-tightening CF for me to trust something like that as cosmetic, rather than structural, especially concerning the seat mast in particular.
That said, I'd inspect by sound -- rap the carbon lightly with the handle end of a screwdriver along the seat mast. If it sounds different, more a dead *thunk* than a sharp *knock*, near the crack, frame would be suspect...
That said, I'd inspect by sound -- rap the carbon lightly with the handle end of a screwdriver along the seat mast. If it sounds different, more a dead *thunk* than a sharp *knock*, near the crack, frame would be suspect...
#14
Ok, so as I understand it, that is a wear line where the seat post used to set. You've raised the seat post, then touched up the wear line with paint a year ago.
So, the cracking and discoloration is due to a bad touch-up paint job.
But, there may also be FLEX at that point which would also crack the paint.
You've ridden your bike some and haven't impaled yourself which is a good sign. You did have it inspected a year ago, but not recently. Do you still have photos of it before the botched paint job?
You could take it back to the shop for re-inspection a year later. However, put it back up on the web. Take good photos, and explain the situation the best you can do (pre touch-up would be good too). Perhaps it shouldn't affect the sale price, but I have no doubt that it will affect the final price as it just looks suspicious.
So, the cracking and discoloration is due to a bad touch-up paint job.
But, there may also be FLEX at that point which would also crack the paint.
You've ridden your bike some and haven't impaled yourself which is a good sign. You did have it inspected a year ago, but not recently. Do you still have photos of it before the botched paint job?
You could take it back to the shop for re-inspection a year later. However, put it back up on the web. Take good photos, and explain the situation the best you can do (pre touch-up would be good too). Perhaps it shouldn't affect the sale price, but I have no doubt that it will affect the final price as it just looks suspicious.
#15
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
Ok, so as I understand it, that is a wear line where the seat post used to set. You've raised the seat post, then touched up the wear line with paint a year ago.
So, the cracking and discoloration is due to a bad touch-up paint job.
But, there may also be FLEX at that point which would also crack the paint.
You've ridden your bike some and haven't impaled yourself which is a good sign. You did have it inspected a year ago, but not recently. Do you still have photos of it before the botched paint job?
You could take it back to the shop for re-inspection a year later. However, put it back up on the web. Take good photos, and explain the situation the best you can do (pre touch-up would be good too). Perhaps it shouldn't affect the sale price, but I have no doubt that it will affect the final price as it just looks suspicious.
So, the cracking and discoloration is due to a bad touch-up paint job.
But, there may also be FLEX at that point which would also crack the paint.
You've ridden your bike some and haven't impaled yourself which is a good sign. You did have it inspected a year ago, but not recently. Do you still have photos of it before the botched paint job?
You could take it back to the shop for re-inspection a year later. However, put it back up on the web. Take good photos, and explain the situation the best you can do (pre touch-up would be good too). Perhaps it shouldn't affect the sale price, but I have no doubt that it will affect the final price as it just looks suspicious.
Anyway, it was worth posting my question here because I doubt I would have even thought this was an option.
Although I do have pictures of the frame before I built it up, there are no close ups of the post. The pic above that is touched up was just the first application of white paint, I've done it a few more times since to make it look better but the white wasn't an exact match as I wasn't too worried about making it perfect, just less noticeable from a distance. Never planned to get hooked and buy a new bike. Thought I'd ride this one until it exploded.
Last edited by Gus90; 01-19-15 at 05:41 PM.
#16
Banned
Joined: Jun 2010
Posts: 43,586
Likes: 1,380
From: NW,Oregon Coast
Bikes: 8
I Rely on the Guys in the Coast Guard Helicopter shop for The high tech Materials Questions.. since they have actual training in working with that stuff..
[My only CF buy was a Mandolin https://cdn.bluegrasstoday.com/wp-con...006/12/n2.jpg]
[My only CF buy was a Mandolin https://cdn.bluegrasstoday.com/wp-con...006/12/n2.jpg]
#17
Thread Starter
Senior Member
Joined: Mar 2014
Posts: 810
Likes: 1
From: Chicago (suburbs)
Bikes: A few too many
I Rely on the Guys in the Coast Guard Helicopter shop for The high tech Materials Questions.. since they have actual training in working with that stuff..
[My only CF buy was a Mandolin https://cdn.bluegrasstoday.com/wp-con...006/12/n2.jpg]
[My only CF buy was a Mandolin https://cdn.bluegrasstoday.com/wp-con...006/12/n2.jpg]
Thread
Thread Starter
Forum
Replies
Last Post
willydstyle
Classic & Vintage
10
12-11-15 08:35 AM
lineinthewater
Bicycle Mechanics
7
01-25-13 07:17 PM








