Go Back  Bike Forums > Bike Forums > General Cycling Discussion
Reload this Page >

Cracked paint or seatpost shaft?

General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

Cracked paint or seatpost shaft?

Old 03-25-19, 03:14 PM
  #26  
phughes
Senior Member
 
Join Date: Mar 2011
Posts: 1,143
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 231 Post(s)
Liked 19 Times in 14 Posts
Originally Posted by RiceAWay View Post
You made the mistake of misspelling "frame"



By the way - There seems to have been a remarkable reduction in breaking carbon frames. I don't know if people are finally getting the idea that you don't complain about a carbon fiber frame breaking when you run into the side of a car at 15 mph or if they are getting the hang of the material and we're getting very few frames and forks breaking without reasons? I have seen this occur but have finally gone back to CF and my Colnago CLX 3.0 is easily the best bike I've ever ridden. But perhaps it just fits me better than most other bikes?
Probably a combination of both.
phughes is offline  
Old 03-25-19, 07:21 PM
  #27  
sdmc530
Heft On Wheels
 
sdmc530's Avatar
 
Join Date: Nov 2014
Location: South Dakota
Posts: 2,003

Bikes: Specialized,Cannondale

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 537 Post(s)
Liked 64 Times in 50 Posts
New frame, that is great CS!
sdmc530 is offline  
Old 03-26-19, 11:54 AM
  #28  
phughes
Senior Member
 
Join Date: Mar 2011
Posts: 1,143
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 231 Post(s)
Liked 19 Times in 14 Posts
Originally Posted by RiceAWay View Post
I made the mistake in thinking the frame was carbon since I saw so many carbon frames broken that way. You made the mistake of misspelling "frame" and Ribble agreed with my assessment that was a dangerous crack.

By the way - There seems to have been a remarkable reduction in breaking carbon frames. I don't know if people are finally getting the idea that you don't complain about a carbon fiber frame breaking when you run into the side of a car at 15 mph or if they are getting the hang of the material and we're getting very few frames and forks breaking without reasons? I have seen this occur but have finally gone back to CF and my Colnago CLX 3.0 is easily the best bike I've ever ridden. But perhaps it just fits me better than most other bikes?
My comment, "Probably a combination of both," was in regards to your comment on the reduction of broken frames.

As for the Colnago CLX 3.0 being the best bike you have ridden, I am sure fit has something to do with it, but nonetheless, it's a great bike. Sometimes it is hard to nail down exactly what what makes a bike feel right for us, but when you find it, it's great. Enjoy!
phughes is offline  
Old 03-26-19, 12:16 PM
  #29  
rm -rf
don't try this at home.
 
rm -rf's Avatar
 
Join Date: Jan 2006
Location: N. KY
Posts: 5,085
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 623 Post(s)
Liked 14 Times in 13 Posts
I worried when my nice carbon frame showed a pair of cracks similar to the 3 and 9 o'clock cracks in the photo, but shorter. I kept a photo to see if they were getting worse or not.

That was 9,000 miles ago. No change at all. Yeah!
rm -rf is offline  
Old 03-26-19, 02:27 PM
  #30  
CliffordK
Senior Member
 
CliffordK's Avatar
 
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 22,424
Mentioned: 166 Post(s)
Tagged: 0 Thread(s)
Quoted: 8523 Post(s)
Liked 79 Times in 71 Posts
Originally Posted by Hoopdriver View Post
I wouldn't drill relief holes just yet, but instead just watch for a while. The big question is how the cracks happened. Assuming that the post is the correct diameter, perhaps something happened during initial assembly. If the seat post is too small, flexing could have done it as would over-clamping. It's certainly worth it to get out the calipers and measure. How do the cracks line up with the post clamp?
Originally Posted by RiceAWay View Post
That is definitely cracking of the seat post probably from overtightening the seat post clamp. This is a dangerous condition and this is one of the few areas on a carbon bike that I would trust a repair. It you let this go it can crack around the circumference and the seat post could out on a hard bump in the least safe place.
Aluminum frame, carbon post.

I also wonder about perhaps a marginally compressible Carbon post being over-tightened.

On the bright side, someone posted a photo of this Tandem a while ago.

Reynolds 531 Gitane Tandem



Steel, of course, but it looks like half the mast was cut off, either by an owner, or at the factory, and it is still stable.

if the post mast was to break (it would take a very long crack), it would result in a twisty post, rather than a sudden loss of the seat.
CliffordK is offline  
Old 03-26-19, 02:55 PM
  #31  
RaihanS
Junior Member
 
Join Date: Jun 2018
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
paint for sure
RaihanS is offline  
Old 04-02-19, 03:47 PM
  #32  
RiceAWay
Member
 
Join Date: Dec 2018
Posts: 33
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked 1 Time in 1 Post
Originally Posted by CliffordK View Post
Aluminum frame, carbon post.

I also wonder about perhaps a marginally compressible Carbon post being over-tightened.

On the bright side, someone posted a photo of this Tandem a while ago.

Reynolds 531 Gitane Tandem



Steel, of course, but it looks like half the mast was cut off, either by an owner, or at the factory, and it is still stable.

if the post mast was to break (it would take a very long crack), it would result in a twisty post, rather than a sudden loss of the seat.
I've had a short seat post hop up high enough that when you were slammed down at the other end of the bump it levered the post over and broke it off. The riding home standing was not all that pleasant. Now I never use short posts like Colnago used to make
RiceAWay is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Philphine
Classic & Vintage
9
02-04-19 04:09 PM
dwellman
Clydesdales/Athenas (200+ lb / 91+ kg)
3
10-10-11 02:06 PM
kpfeif
Classic & Vintage
2
03-24-08 10:36 AM
Grasschopper
Bicycle Mechanics
5
03-17-05 09:17 AM
recursive
Foo
2
09-24-04 04:09 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.