Carbon frame "life expectancy"

[patentcad]

??? Have you read your C'dale warranty? Like all the major brands, it specifically excludes fatigue failures due to normal wearout. Cannondale, of all companies, are upfront about admitting their frames aren't designed to last forever.

After speaking with a few Cannondale dealers and owners, I'm confident that few firms are as liberal in their warranty replacement policy as they are. Besides, in today's cycling business, who knows if any of these firms will actually still be in business in 5-10 years? What's the big downside of a broken Cannondale frame? That I'll have to lay out $1000 for a replacement frame after 20-40K miles because they won't replace it for free? At that point I'm not sure I'd be so upset that the bike owed me a thing. I wasn't that upset about the Merlin's failure - more at the company's complete unwillingness to help me in any meaningful way - I expected some reasonable repair estimate, and that wasn't forthcoming. Their response? 'You may as well buy a new frame' - all because I wasn't the original owner, but somebody who bought a Merlin with 500 miles on it. That was pretty stupid on their part in my view. I've since told dozens of cyclists (who all buy high end bicycles) that their titanium frames BREAK from normal use. Smart business strategy eh?

NOTHING lasts forever. And if you ride a bicycle 30-40K miles with no thought of replacing it, you,re not thinking. The bike may not be broken, but I can assure you it's not the same. Metal/carbon fiber breaks down, and after 5+ seasons it's not like it was when it was brand new, period. That's one of the reasons pros get new bikes (more than one) EVERY season. Nobody understands this better than they do.

Part of this depends on whether you're invovled in competitive riding I suppose. That's where the equipment really seems to make a marginal difference on very tough rides/races. If all I did was ride alone 100% of the time I'm not sure it would be the same concern. My new Cannondale feels great, and I'm sure if it breaks in the first few years they'll ship me a new one in a week. After that - I should live that long.

 

[artmichalek]

I wasn't that upset about the Merlin's failure - more at the company's complete unwillingness to help me in any meaningful way - I expected some reasonable repair estimate, and that wasn't forthcoming. Their response? 'You may as well buy a new frame' - all because I wasn't the original owner, but somebody who bought a Merlin with 500 miles on it. That was pretty stupid on their part in my view. I've since told dozens of cyclists (who all buy high end bicycles) that their titanium frames BREAK from normal use. Smart business strategy eh?

Either you're being too sensetive, or the Merlin rep you spoke too didn't phrase things too well. If you break a chainstay and a downtube on a ti frame, there is absolutely no way to fix it that's going to be cheaper than buying a new one. It's not like steel where it's relatively easy to cut the broken tubes out and put in a new ones.

 

[patentcad]

Either you're being too sensetive, or the Merlin rep you spoke too didn't phrase things too well. If you break a chainstay and a downtube on a ti frame, there is absolutely no way to fix it that's going to be cheaper than buying a new one. It's not like steel where it's relatively easy to cut the broken tubes out and put in a new ones.

I'm sure you're right - that it had more to do with a boneheaded Merlin employee not communicating this to me the right way. I was still very surprised at the time the frame broke - and so is everybody else I relate this story to.

But it does sort of underscore the 'everything breaks eventually' point.

 

[Adam-from-SLO]

Good points everyone

I'd just like to add, that I've ridden a couple of different Carbon bikes.

1. LOOK KG 286 Monocoqe : sure, it weights like a carbon bike = 3 lbs. for a 56cm frame ... but the ride is more like a steel frame- which there is nothing wrong with this This also, in part may be due to the beefy BB area + seat tube that is kinda aero- larger tube diameters.

2. Colnago C-40 . Hand layed carbon fibers, full Carbon lugs, ... in a specific directional method, tube to tube, to help counter act the forces of torsion/torque/etc. etc- physics properties. This frameset is forgiving(shock absorbing) unlike the Look Monocoqe ...... yet stiff where it needs to be- when out of the saddle / or climbing, etc. A very well put together frame.

Both bikes with 1" head tube. Are there any real differences / effects on a larger 1 1/8" headtube ? I'd suspect not, with lighter riders.. maybe with heavier riders ??

***Also, has anyone heard of the usage of 6/4 Titanium in frames (ie. Litespeed Vortex) , ALWAYS having "seams" in the tubing manufacture......(the Vortex down tub is beefy- but looks to be welded at two points to help create the tube-- its like a large oval/diamond shaped tube. Yes, 6/4 Ti is stronger then 3/2.5 Ti ......... but if there is seems in the tubing, that can be a weak link over time. I believe I read this on Seven Cycles web site - comparing the two forms of Ti. tubing.

 

[brhinobiker42]

The comment about all metal frames failing eventually is incorrect. Only aluminum is guaranteed to fail because of cyclical loading and fatigue. Aluminum is also extremely ductile, which means it will tear under sufficient stress. If steel and titanium are not stressed past their yield point, which is very close to ultimate tensile strength (especially for titanium), they will not fatigue at all. Steel will likely rust, eventually. If primed and painted properly, it can last several generations. Titanium, which does not rust, will last indefinitely. Any metal can break if crashed hard enough, but only aluminum is doomed to failure through average, everyday use.

Carbon fiber, however, which has a high tensile strength, is very brittle, and thus can rupture suddenly under loads from angles the tubing was not designed to withstand. Once cracked, you have a useless piece of plastic. That's why there is no "lifespan" on carbon fiber.