Calling to CF experts (Samu Illonen?) - Cannondale issue

[clm2206]

Hi,

This frame is a Cannondale System Six and belongs to a friend. Buyed brand new, and after three months of regular riding (he is 18.0 m, 78 kg.), during a ride, something sounded like a big snap (no hole, no crash), but nobody noticed where it came from. After the ride my friend realized this crack on the down tube. Clear coat is intact. Dealer says it is undoubtely a crash, and makes my friend the big favor of making him pay $750 for a crash replacement guarantee. Any inputs?



Regards

[Kuiper]

I would send an e-mail to the Cannondale Customer Service.

No damage on the clearcoat? pure under it?

[clm2206]

I would send an e-mail to the Cannondale Customer Service.

No damage on the clearcoat? pure under it?

No damage on the clear coat, I've seen it and have some experience on painting issues. However, Cannondale CS agrees with the dealer!! Or at least that's what the dealer says. At this point I don't know.

This happened a couple of months ago, but a guy here posted a picture of an Addict out of the box with exactly the same kind of fracture and Scott immediately apologized and told him to change the frame. This is why I post this picture and ask your opinions.

[stella-azzurra]

Doesn't look like a result of a crash but more like something hitting it. There is point of impact with cracks going out.

[clm2206]

Doesn't look like a result of a crash but more like something hitting it. There is point of impact with cracks going out.

That something should have damaged the clear coat at least in one point. And that's not the case.

[babylou]

You say the clear coat is not damaged? Doubtful that a crack like that would create an audible "snap" unless there is significant damage to the clear coat. Also the crack does not appear in a high stress area. Finally, the crack radiated away from a single point leads to impact at this point.

[clm2206]

You say the clear coat is not damaged? Doubtful that a crack like that would create an audible "snap" unless there is significant damage to the clear coat. Also the crack does not appear in a high stress area. Finally, the crack radiated away from a single point leads to impact at this point.

The clear coat is intact. I have some years of experience with painting and I'm sure about that. If you push your fingers around the crack the clear coat doesn't even show a gap or damage. It seems like the tube failed (too few CF layers maybe?) from the inside. Sounds weird, that's why I'm asking for your opinions.

I don't know if that snap was related to the crack, probably yes, probably not. I only said on that particular ride that snap was the only weird thing that happened. Besides that, no crash, no fall, no nothing, I was there.

[Dynamic]

Have you actually touched the clearcoat?

[clm2206]

Have you actually touched the clearcoat?

Of course. As I told before, I've pushed my fingers on the crack, and ther is no sign of gap or damage on the clear coar. It seems the damage come from the inside. Actually, the tube doen't even move a milimeter back when pushed by hand. It seems an internal fracture.

[bikemesenger]

Because carbon is so stiff it is very common for the tube to crack but not the clearcoat. The clearcoat is not flexed far enough for it to crack but it takes very little flexing for the carbon to crack. To me that crack looks like something hit the downtube. When your friend heard the crack is most likely something being kicked up by the front wheel and smacking into the downtube.

[CharlesM]

That or something getting kicked sideways from the road...

[clm2206]

Because carbon is so stiff it is very common for the tube to crack but not the clearcoat. The clearcoat is not flexed far enough for it to crack but it takes very little flexing for the carbon to crack. To me that crack looks like something hit the downtube. When your friend heard the crack is most likely something being kicked up by the front wheel and smacking into the downtube.

Thanks for your input. Your explanation makes sense, but I can't believe CF being so weak. We were a bunch of 20 riders making a century at low pace, nice road, no holes, no stones, no debriss. He was at the 4th or 5th position, I was ahead of him. As far as I remember, there was no object he could kick up with his front wheel, and as Pez says, the object should have come sideways from the right. What was it, a bullet?

I've ride and raced for years, and had my frames being kicked by stones of all sizes, being a chipped clear coat the worst issue. Never seen a crack like this.

[bobbyOCR]

Although bikemesenger said it.

I think it was a stone hit or other potential missile. It is purely bad luck.

[theremery]

An unseen stone pinged off a tyre would be my guess. Bummer...what horrible luck. This is what scares me a little about carbon frames.

[sandbaggio]

The best you might be able to do is try and push up the ladder. Call Cannondale directly (18002453872), ask to talk to someone in customer service, AND someone in testing. If you can persuade them, you would definitely need to send the bike back for examination.

I understand your concerns, and its a difficult problem to diagnose via a photograph. That being said, I understand their doubts. You hear plenty of JRA stories. A Dupont clear uretane clear coat didn't crack, but a vinyl decal beneath it did? That seems a bit odd. The star of the impact definitely looks like the frame was point loaded. striations appear to follow the +/- 45 layers closest to the surface of the tube. That would take a fairly significant force load unless there is nothing supporting it underneath.

Good luck with your claim. Cannondale has (in the past) dealt with these on a case by case basis, hopefully they'll see the light and extend you a warrenty frame.

Hi,

This frame is a Cannondale System Six and belongs to a friend. Buyed brand new, and after three months of regular riding (he is 18.0 m, 78 kg.), during a ride, something sounded like a big snap (no hole, no crash), but nobody noticed where it came from. After the ride my friend realized this crack on the down tube. Clear coat is intact. Dealer says it is undoubtely a crash, and makes my friend the big favor of making him pay $750 for a crash replacement guarantee. Any inputs?



Regards