Carbon Frame Longevity



beckirk

New Member
Nov 17, 2003
9
0
0
I am shopping around for a new bike and really like the carbon frames, but I plan to keep the bike for a long time. I was wondering what kind of lifespan today's carbon frames have.

TIA

Kirk
 

boudreaux

New Member
Oct 16, 2003
5,133
0
0
Originally posted by beckirk
I am shopping around for a new bike and really like the carbon frames, but I plan to keep the bike for a long time. I was wondering what kind of lifespan today's carbon frames have.

TIA

Kirk
As long as anythig else if not crashed or abused. A 'long time' is a bit vague.
 

beckirk

New Member
Nov 17, 2003
9
0
0
Originally posted by boudreaux
As long as anythig else if not crashed or abused. A 'long time' is a bit vague.

I should have been more specific. I plan on keeping the bike for something like 7-10 years unless I win the lottery of course! Is crashing an issue with the carbon? I guess the right crash can destroy any frame but is the carbon more susceptible to damage?
 

turbo6bar

New Member
Oct 21, 2003
11
0
0
Kirk, I was riding my Trek 2100 when a car pulled a left turn across my path. I collided with his rear quarter panel. The Trek 2100 has aluminum main tubes with aluminum lugs. My fork was bent, front wheel bent, along with other damage to components. However, the frame itself looked fine. Upon consulting with others, including several bike shops, many expressed concern about the integrity of the carbon fiber tubes in such an accident. Well, I'm getting a new bike. On the other hand, one doesn't know if a frame built from another material would have done much better.

The Trek frame was going on 7 years old, with unknown mileage. I would not hestitate to say carbon fiber is definitely a durable frame material. From what I've read, carbon fiber is not going to be very good against direct impacts. Despite the accident, I am still considering a carbon frame bike from Giant or Kestrel. Still shopping and recovering from the accident.

Regards,
Jurgen
 

dhk

New Member
Sep 1, 2003
2,259
0
0
74
Yes, since CF doesn't dent or bend like metal, it's hard to inspect visually for internal cracks or delamination . I think ultrasonic or X-ray equipment could be used by an experienced NDT guy.
Without this inspection, can understand why the LBS would not want to tell you it's ok.

A simple "tap test" with a coin is often used to detect gross failures in composite panels, but you have to know what a bad section sounds like. Don't know if this technique would work on tubes or not. Maybe others have experience here.

Concerning fatigue life, the only testing I've seen is the German "Otto" test, which relates frame life to a number of cycles at a certain load. The idea is to simulate standing climbing or sprinting, which is really the only time you're stressing the frame.

The frames that pass 100K or 200K cycles at an increasing load are awarded a certification for a certain level of use, ie, touring, road sport or full-on race use. You can check it out at:

http://damonrinard.com/EFBe/frame_fatigue_test.htm

Dan
 

SLS

New Member
Sep 14, 2003
157
0
0
Originally posted by beckirk
I am shopping around for a new bike and really like the carbon frames, but I plan to keep the bike for a long time. I was wondering what kind of lifespan today's carbon frames have.

TIA

Kirk

I have a Trek 2100 that to my recollection is right around 12 years old. Any car crashes - all bets are off. The occasional fall, etc... you shouldn't have any problems. Next bike I get will be carbon, unless something else better come along. Hope this helps.
 

boudreaux

New Member
Oct 16, 2003
5,133
0
0
Originally posted by beckirk
I should have been more specific. I plan on keeping the bike for something like 7-10 years unless I win the lottery of course! Is crashing an issue with the carbon? I guess the right crash can destroy any frame but is the carbon more susceptible to damage?
I'm the second owner of a 1998 Trek 5500 CF that is still as sound as the day it left the factory. There ae plenty of much older ones around. CF is probably more susciptible to impact damage than some other materials.
 

byron27

New Member
Oct 19, 2003
919
1
0
47
The best frame i ever had was a giant CFR1. I rode it day in, day out for 9 hours a day for 5 years as a messenger and it was the only frame to never crack. I still have it after 9 years (it is in the shed now, i cant bear to part with it). Based upon that i dont think you can fault CF.
 

dhk

New Member
Sep 1, 2003
2,259
0
0
74
Originally posted by boudreaux
Stastically and scientifically bankrupt.

OK, so much for science. I know the trial and error system has worked well over the last 100 years of frame evolution. But, as the mass-market 2.5 lb frames are now here, my guess is all the major mfg's are doing some tests like this....probably a lot more extensive.

Dan
 

boudreaux

New Member
Oct 16, 2003
5,133
0
0
Originally posted by dhk
OK, so much for science. I know the trial and error system has worked well over the last 100 years of frame evolution. But, as the mass-market 2.5 lb frames are now here, my guess is all the major mfg's are doing some tests like this....probably a lot more extensive.

Dan
Some makers may test theirs. Others just put them out for 'market test'. Failures tend to be in defects in material or fabrication rather than failure from type of material. Materials engineering is not exctly new science,and everything use to be overbuilt. If one wants a superlight frame of any material,they should not also be ragging on durability.
 

DesertRider

New Member
Nov 6, 2003
64
0
0
Originally posted by boudreaux
Some makers may test theirs. Others just put them out for 'market test'. Failures tend to be in defects in material or fabrication rather than failure from type of material. Materials engineering is not exctly new science,and everything use to be overbuilt. If one wants a superlight frame of any material,they should not also be ragging on durability.
Got that right!
 

CannondaleRider

New Member
Oct 21, 2003
24
0
0
Originally posted by dhk

Concerning fatigue life, the only testing I've seen is the German "Otto" test, which relates frame life to a number of cycles at a certain load. The idea is to simulate standing climbing or sprinting, which is really the only time you're stressing the frame.

The frames that pass 100K or 200K cycles at an increasing load are awarded a certification for a certain level of use, ie, touring, road sport or full-on race use. You can check it out at:

http://damonrinard.com/EFBe/frame_fatigue_test.htm

Dan
-----
That was a very interesting read, I'd love to see how the CAAD7 fairs...Got a feeling it would bomb out though...

C'Rider
 

dhk

New Member
Sep 1, 2003
2,259
0
0
74
Originally posted by CannondaleRider
-----
That was a very interesting read, I'd love to see how the CAAD7 fairs...Got a feeling it would bomb out though...

C'Rider

If you check the link to the latest test results, CAAD 7 is listed as having passed the highest standard. Pretty impressive.

Note, it's stated that only manufacturers who give permission to show their results are listed.

Dan