Opinions on a seat tube carbon crack

michaelhatzakis Posts: 2
edited December 2013 in Road general
I just noticed a 1 3/4" crack at the bottom of the seat tube just above the bottom bracket. Wilier is away for two more weeks on Christmas holiday and really don't want to be off the bike another month while i wait for them to reply.

The frame is 4 months old. No accidents, no falls, once on a bike rack, but no incidents, basically, the frame has seen no trauma of any kind, except my legs..!! I tapped it with a coin and the sound changes directly on top of the crack ever so slightly, but even a 1/16 of an inch above and below, no change in sound at all. No creaking when I ride.

So, for a month or so, what are the opinions as to whether this looks safe? See attached images. I know, I am looking for just opinions.



  • I wouldn't ride it faster than walking pace, I probably wouldn't pedal either. I think go for it, take a few spokes out of the front wheel too for extra excitement.
  • It looks more than just paint...
    left the forum March 2023
  • ianbz
    ianbz Posts: 27
    I'm a non destructive test engineer, using ultrasonics to check for delaminations on carbon fibre. I'd recommend getting it checked out. With carbon fibre composites (cfc) you get barely visible impact damage (bvid). Basically the carbon delaminates Christmas tree style from outer to inner. The impact point would be the top of the tree and the bottom of the tree would be somewhere below the surface. I'm not saying that you have had any impact damage but that certainly looks suspicious. The paint applied should flex enough without cracking unless there is something flexing underneath the surface which I would say is happening here!
  • Oo, that does look a little nasty :?
    I personally wouldnt ride it, sorry to say.
    I too only have one bike, and was knocked off on the 4th of this month, still waiting to get the replacement sorted via the insurance claim (cheques cleared, frames chosen, building on Monday, sooo close :evil: ) and due to the damage to the frame I didn't want to chance riding it.
    However, I couldn't face a month off, so have used the cracked bike on a Turbo and worked on intervals in the meantime.
    Hope you get it sorted soon tho mate ....
  • As others have said, take a few spokes out of your wheels, loosen your stem and handlebar bolts, slacken off your Q/R's and find a long descent.
    I'm sorry you don't believe in miracles
  • Bobbinogs
    Bobbinogs Posts: 4,841
    Personally, there is no way I would ride that bike. I am lucky to have other options but, even if I didn't, I wouldn't want to risk hitting a small bump and find the bike fall apart like some comedy clown contraption.
  • walts
    walts Posts: 4
    Get it repaired, plenty of places will do that and have it like new.
  • mfin
    mfin Posts: 6,729
    The poll can't be answered, also it will fail a damn sight quicker if you are hefty and/or your roads are poor. Either way it's heading for replacement, posting a photo on a forum with a poll to try to decide whether to keep on riding it is quite funny.