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Carbon seat/chainstays durability question...(21 posts)

Carbon seat/chainstays durability question...voodoorada
Jul 28, 2003 10:31 AM
Hello,
I am looking into getting a scandium frame bike with carbon fiber seat and chain stays. I know carbon has a limited lifespan, so I was wondering if I should make such a big investment in a bike that may need to be replaced in a few years. I don't race, but I ride pretty hard, do lots of climbing, and I weigh about 185. If I get this bike, will I just have to accept that I can only ride it for a few years, or will this bike be around 10 years from now?

I currently ride 853 steel so I don't have to worry about those problems. Any advice would be greatly appreciated, your own experiences, etc. Thanks!
My carbon bikes are 14 years, 11 years and 1 year old..Dave Hickey
Jul 28, 2003 10:42 AM
The 14 year old frame rides as well as the 1 year old frame.

Carbon doesn't have a limited lifespan(unless you crash).
That's quite a spread. Was the 1 year old a surprise?djg
Jul 28, 2003 11:12 AM
Sorry.
wife out of town and 1 night with an unprotected credit card nmDave Hickey
Jul 28, 2003 11:21 AM
LOL you guys are killing me nmJS Haiku Shop
Jul 28, 2003 11:23 AM
I'm serious:-)Dave Hickey
Jul 28, 2003 12:08 PM
Mrs H was out of town and I was sitting by the pool drinking Coronas. I started to read some bike porn(New Excel catalog) I called to check on sizing and the Excel guy was very good......I told him I'd call him back in the morning after I checked with my wife. He replied " We'll ship it to your office and she'll never know".... I ordered it that night:-)))
angel on left shoulder, excel on right shoulder (nm)JS Haiku Shop
Jul 28, 2003 12:20 PM
I'm serious:-)djg
Jul 28, 2003 2:20 PM
Now that's a salesman--even sneakier than my guitar salesman's "it is easier to seek forgiveness than permission."
As long as Iban Mayo doesn't fall on it...mohair_chair
Jul 28, 2003 10:49 AM
The "limited lifespan" of carbon far exceeds your own, probably by hundreds or thousands of years. Get the bike.
re: Carbon seat/chainstays durability question...otiebob
Jul 28, 2003 11:28 AM
Barring a crash, the carbon fiber will outlast the rest of the bike. Scandium is not known for its longevity...
I think it was Trek who had a graphic showing fatigue cyclespitt83
Jul 28, 2003 11:31 AM
Titanium dropped off first after a certain number of stress flexing cycles. Steel was second before failure Aluminum lasted about 50% more than steel. Carbon fiber stayed at 100% compliant for millions more cycles than any other material. I know I'll get flamed by the "steel is real" crowd, but that's what the data showed.
Say it aint so, JoeMink
Jul 28, 2003 12:09 PM
I just dropped a bundle on a titanium and carbon bike (Colnago CT1). I thought the carbon would go first, and now you're telling me it's the titanium. Oh s#%t, I've just remembered I'm going to take a flight soon, and a lot of the airplane parts are Ti. So much to worry about, so little time...
Actually, heres an independent test on fatigue.huez
Jul 28, 2003 3:07 PM
Carbon and aluminum came out on top. It depends on the frame. It can be done right with any material I would guess. Steel and ti cant compete though in weight.

http://sheldonbrown.com/rinard/EFBe/frame_fatigue_test.htm

Someone said Scandium is not known for its longevity. Well, its actually much better in fatigue resistance than aluminum. Scandium is promising.
Fascinating. Amazing. Thanks. (nm)mapei boy
Jul 28, 2003 4:47 PM
Carbon has a lot of appealing qualities but,Ken of Fresno
Jul 28, 2003 2:23 PM
I wonder what would happen the first time you drop a chain and it gets wedged between the stay and the small ring. With steel or ti I think loss of paint would be the biggest worry. I'd hate to see a carbon stay scratched down to the fibers from a simple and not all that uncommon incident. And what's the likelihood of a future failure due to a stress riser? Any thoughts on this from carbon owners that have experienced a wedged chain? I'd love to have a carbon bike myself (some of them are among the most beautiful designs I've seen), but the whole abrasion resistance is, in most applications, I think equally important as the "stress flexing cycles." Carbon freewheel cogs anyone?

Ken
Yeah, did it with my Trek mtbJervis
Jul 28, 2003 4:39 PM
a couple of times. I always heard you're not supposed to put scratches or gouges in carbon, the chain took a good chunk out of the bottom bracket section of my frame (it was one of those instances when you didn't realize it was off and you hit the pedal hard). A couple hundred miles, off road, later it still hasn't had a lick of a problem, even with the old Trek's super flexy bottom bracket. If you like the ride of CF go ahead and get one, won't regret it. Disclaimer: I ride a 95 CF, I don't know how CF manufacturing has improved/degraded over the years but I'm sure newer frames will have different properties. Plus it was a mountain frame.
Yeah, did it with my Trek mtbBaadDawg
Jul 29, 2003 5:58 AM
I put a nice gouge on my 2 month old Giant TCR Composite when I threw a chain off the inner and it jammed and bent the chain. Had to walk 5k home after a 90k ride. I was pissed. My chain came off not even under load and jammed on the 1st pedal revolution (wasn't mashing at all) but I didn't know it had even come off.

I was very worried about this and have asked a Giant rep to examine the bike, but my LBS says they probably won't do anything about it.
My thoughts at the time were geez if it were steel or aluminum I would have some paint chips not chunks missing.

Now it's wait and see although probably nothing will result from it.

Would buy this bike again in a heartbeat. Its amazing.
WedgieHalfWheelin
Jul 28, 2003 9:54 PM
Got one on my 00' 5200. I took it to the trek peeps at my LBS. Luckily I wasn't climbing so the damage was minimal (paint) but 3 years later... ROCK SOLID! They said not to cover it up (re-paint)so I could continue monitoring the spot. Since it is reinforced by the BB, they seemed pretty confident in their prognosis.
Tell you what Ken...cyclequip
Jul 29, 2003 12:36 AM
Depends on the bike. Most bikes with carbon stays can be repaired quite easily should this happen. Simply replace the stays if they get damaged.
Good, but what ifKen of Fresno
Jul 29, 2003 4:24 PM
the whole frame is carbon?
Carbon has a lot of appealing qualities but,Ken of Fresno
Jul 28, 2003 8:55 PM
I wonder what would happen the first time you drop a chain and it gets wedged between the stay and the small ring. With steel or ti I think loss of paint would be the biggest worry. I'd hate to see a carbon stay scratched down to the fibers from a simple and not all that uncommon incident. And what's the likelihood of a future failure due to a stress riser? Any thoughts on this from carbon owners that have experienced a wedged chain? I'd love to have a carbon bike myself (some of them are among the most beautiful designs I've seen), but the whole abrasion resistance is, in most applications, I think equally important as the "stress flexing cycles." Carbon freewheel cogs anyone?

Ken