Found a crack! [pic]

[Shrike]

Took the rear wheel off to replace the derailleur hanger and thought I'd take the chance to clean the inside areas of the seat tube, chain stays etc. Looky what I found





Looks like a stone or something must have kicked up between there and the wheel at some point. Hole goes all the the through, can poke a thin hex key all the way through. Going to put a bit of electrical tape over it and ride on. Should be fine, right? Get it repaired come winter.

[sungod]

is that the seat tube?

if it's small probably ok, though from the first pic the pattern of reflection looks different across the full width

is that simply a chance of lighting/camera angle, or is it because the tube is actually deformed across the full width?

if it's the latter i'd be concerned as what used to be a box section may effectively have become a u-section, which'll expose the rest of the material to increased stress

cf repair shop should be able to fix it without drama

[maverick_1]

Damn, sorry about the damage..
You may need to check on the surrounding areas to see if the crack has propagated or otherwise, just to be safe.

Btw it that a Canyon or Cervelo?

Cheers

[Shrike]

Sorry yeah, dodgy angle that. Canyon and Cervelo both use this similar shape. This is a Cervelo though. Probably makes more sense if I post it like this





@sungod, the area does look deformed but it's like that normally

Hole is pretty central, paint damage is a bit wider, but there's no crack running along the length or breadth of the seat tube. Just looks like someone took a nail gun to the middle of it

Sent off to a carbon repair place for their opinion and quote. No chance this is going anywhere for the next 3/4 months anyway, rare we get good weather here

[Valbrona]

Caused by bottom of seatpost?

[Shrike]

Good thinking about the seatpost Val!

Took the wedge out and pushed the post all the way down and sure enough, the edge hits that hole. I had a post slip issue over a month ago, this must be from then. Post is cut with an angle at the rear of it, but the angle isn't severe enough. I'm going to trim a bit more off this weekend so if it ever slips again badly it won't make the hole worse.

Actually kinda relieved. Solved the post slippage so this shouldn't get worse as it's not damage from regular riding.

Cheers!

[goodboyr]

Deleted.

[Calnago]

Wouldn't that be a valid warranty claim. I would think so.

[Shrike]

It would I'm sure Cal, but I overtightened the clamp. Read online somewhere it was 12nm, it's actually 8nm. 12nm is for another seatpost bolt

Not the only one who's mixed those two up as it turns out!

I've made a mixture of two types of pastes and use 7.5nm, that's fixed the slippage it seems so hopefully this is the end of that saga

[BikeAnon]

Shrike, if you're going to keep riding it, I think it would be worth mixing some thin epoxy, getting in the hole with a flat toothpick and swiping it around.

This should wick into any edges, and might prevent further spreading. In that spot, it seems you're safe anyway.

Now that I've done some DIY carbon-fiber repairing, I've gone from being worried about cracks to feeling like I have a little knowledge.


If that were my hole, I'd patch it myself. Would take a few hours of work, and two days off the bike. Bonus.... no one will ever see the patch!

[wingguy]

Looks like a stone or something must have kicked up between there and the wheel at some point.

Nope. Think back to that time you rode it and the seatpost slipped down, that's the bit the seatpost hit.

[wingguy]

Actually kinda relieved. Solved the post slippage so this shouldn't get worse as it's not damage from regular riding.

Umm.... that's not how carbon fibre works. To be honest, that's not how any material works

I rode a cracked bike for a while and it was fine, but that doesn't mean it always will be. I'm sure sooner or later it would have deteriorated badly. I don't know what kind of forces act on that part of the seattube but if there are any then the damaged section is a weak point and a massive stress riser for them. Doesn't matter how it got there.

[tarmackev]

Not sure it would be a warranty, no way of proving what the clamp was torqued too, could be worth a try though.
Not saying I don't believe you, I do 100%, just coming at it from the Cervelo point of view. Hopefully they'd help in some way.
If not get it repaired, in the U.K. that would be £200-ish by the guys who fix the Sky-British cycling bike. Worth the money alone for peace of mind.



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[tranzformer]

Good thinking about the seatpost Val!

Took the wedge out and pushed the post all the way down and sure enough, the edge hits that hole. I had a post slip issue over a month ago, this must be from then. Post is cut with an angle at the rear of it, but the angle isn't severe enough. I'm going to trim a bit more off this weekend so if it ever slips again badly it won't make the hole worse.

Actually kinda relieved. Solved the post slippage so this shouldn't get worse as it's not damage from regular riding.

Cheers!

Looks like a stone or something must have kicked up between there and the wheel at some point.

Nope. Think back to that time you rode it and the seatpost slipped down, that's the bit the seatpost hit.

What a useless post after OP already stated 5 posts above yours that he figured out it was the seat post. Why would you even quote and respond to the first post when OP already figured out what caused it and is past trying to figure out what caused it? Sheesh.

[Shrike]

Good thinking about the seatpost Val!

Took the wedge out and pushed the post all the way down and sure enough, the edge hits that hole. I had a post slip issue over a month ago, this must be from then. Post is cut with an angle at the rear of it, but the angle isn't severe enough. I'm going to trim a bit more off this weekend so if it ever slips again badly it won't make the hole worse.

Actually kinda relieved. Solved the post slippage so this shouldn't get worse as it's not damage from regular riding.

Cheers!

Looks like a stone or something must have kicked up between there and the wheel at some point.

Nope. Think back to that time you rode it and the seatpost slipped down, that's the bit the seatpost hit.

What a useless post after OP already stated 5 posts above yours that he figured out it was the seat post. Why would you even quote and respond to the first post when OP already figured out what caused it and is past trying to figure out what caused it? Sheesh.

But you know, internet points. Besides, I now know that riding your bike causes stresses on the bike. That's how materials work!

Of course I'm going to check it regularly until I get it fixed after the summer. Goes without saying.

Bikeanon, good thinking there. Have some Gorilla epoxy I can do over the edges. Will do it in the morning. I am pleased though, way better knowing what caused the damage than being clueless and worrying it's going to be something recurring.