Hi all
Just looking for some general feedback from you all on whether wheel/tyre rub and indentation on carbon bike chainstays is anything to be overly concerned with? I ride a 2010 Scott CR1 Pro with 25mm (Michelin Pro4 service course tyres) on Dura-ace C24s or Mavic Cosmic Carbone SLs.
My LBS on a recent frame inspection had declared that my chainstay was 'cracked' based on a quick visible inspection (all of two minutes). Having looked a bit closer myself afterwards, what they are mainitaining as a crack is a fairly uniform indentation in the paintwork on the inside of both chainstays in line with where the tyre is closest to the chainstay. There is not a lot of clearance for 25mms on my Scott CR1 however there is certainly no apparent chain rub when climbing or putting the power down.

Having researched on the internet, there are a number of posts identifying a similar issue either due to wheel flex or where new tyres have a rubber edge or stalks which catch on the chainstays.


I intend to get a second opinion from another LBS for piece of mind but just wanted to gauge the forum here for experience here? Perhaps I need to revert to 23mm tyres to prevent any further wear on the paint lacquer??



CXR94Di2 [2080 posts] 3 years ago

I would of thought that the wear marks wont have detremental affect, until you come to sell the bike then its virtually worthless from a buyers perspective!

This is the position I was in, in that I always wanted wider tyres than 23mm so went for cyclocross frame, so I can run upto 35mm tyres+ I required hydraulic disc brakes.

jimc101 [81 posts] 3 years ago

Scott CR1's don't have a lot of clearance, thinking 25mm is pushing it too much as you have round out. With 23mm Service Course, there is just about 2mm on each side of the chainstays, that would go down to 1mm clearance with the 25mm's you had.

As CXR notes, the wear won't affect you, but your bike now has very little if any resale value due to this wear.

SPAM Naval [139 posts] 3 years ago

thank you both for the comments. Not too worried about resale value as its a four year old frame anyway but its certainly something I'll bear in mind for any future (n+1) purchase/s as its not something i had considered an issue when I had changed to 25mm tyres even with the limited clearance available.
will be one of my first questions in future!!

Leeroy_Silk [171 posts] 3 years ago

Out of interest how deep are the indents / score marks? If it is just the coating you'll have nothing to worry about, but is there a chance the indent has gone beyond the coating and started to wear the carbon?
I'd be surprised if the paint was thicker than 100 microns (0.1mm or the avg. thickness of a human hair), if the indent feels deeper than that you may have worn through the coating.

I'd still get a second opinion.