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Old 09-05-08, 05:47 PM   #1
hipster_doofus
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Old Carbon Fiber .. death trap?

I thought I got a good deal on a road bike, but now I'm afraid to ride it. It's a Specialized Allez "Epic" and from what I've read on the Internet it was probably made in 1989 or so. It's light and rides nice but I didn't know the whole "CARBON FIBER BLOWS UP AND KILLS YOU" thing when I got it. Now I guess it's an "Epic" failure on my part.

I'm thinking I should just take the 105 hardware and put it on a old metal frame.

It's a 60cm and I weigh probably 225lbs or so.

Tell me it's going to break in half and impale me in the street, and you'll save my life.
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Old 09-05-08, 06:00 PM   #2
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Nobody can tell you that without at the very least inspecting the frame for themselves.
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Old 09-05-08, 06:18 PM   #3
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its going to break in half--- you are going to kill yourself.... whew
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Old 09-05-08, 06:26 PM   #4
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Inspection of the frame should pick up any major problems. Frames in
that era were glued together tubes on lugs and problems include
failure of the glue line at lugs. The coatings on the CF can deteriorate
and make the surface look crappy. A friend had an early '90s similar
frame that came loose at the BB and he simply regued it with more
modern epoxy and rode it for a year or two before replacing. It was
used and about 12yrs old when he got it. Tapping the tubes should
produce a slightly musical note and not a thud. Significant cracks
will almost always telegraph through to the surface. A good exam
should be enough to start.
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Old 09-05-08, 06:35 PM   #5
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its going to break in half--- you are going to kill yourself.... whew
Thanks guys! I knew I could count on the Internet for sagely advice. There's some surface scars on the frame but nothing major. I'm still pretty afraid of it so I think I'll sell the frame on CL with enough warning the clear my conscious.

.. anyone want a used road bike frame?


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Originally Posted by sch View Post
lots of info
Thank you for that bit of information too. I might take it riding this weekend while I'm shopping for another frame.

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Old 09-05-08, 11:33 PM   #6
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I don't blame you. A guy at work had a /new/ carbon bike snap on him. Luckily he wasn't hurt and he got a replacement frame for free. He rides the new frame but if it was me, I think I'd switch... I'm sure the major danger of carbon bikes is being hit by a car, etc but I still feel more confident on steel.
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Old 09-06-08, 02:09 AM   #7
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If you like sleeping at night, then I suppose that you don't want to know about the failure modes of aluminium bicycle frames.


To put this in perspective, have you heard of an overwhelming number of liability claims putting bicycle manufacturers out of business. Probably not. There are stories of carbon frame failures out there. Some of them are actually true. There are also stories of aluminium or steel frame failures and some of them are also true. The internet, while a great source of information, is also one of the worlds best sources of misinformation.

Do the same thing with your bike that you would do with any other, inspect it (or if you don't know what to look for have it inspected) every now and then, maintain it, repair it as necessary and ride it.

Now the disclaimer. At 225lb riding weight, inspect your bike more often, even your non carbon one. Weigh carefully your options for some equipment (pun intended) and pay attention to manufacturers limits. There are weight limits for some components used on bicycles because that's the nature of compromise when producing performance at a given weight. One of the best examples of this is titanium axles for pedals.
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Old 09-06-08, 05:54 AM   #8
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it is true that carbon will not yield like steel will so you will not get a warning before failure. HOWEVER carbon is extremely strong material. the tensile strength is typically over 100ksi. you may need to worry about fatigue failure, however the carbon will get less stiff as it fatigues. you can probably feel it get mushy long before it will break, at least you can in rowing. I've never ridden a carbon frame to failure before.
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Old 09-06-08, 06:01 AM   #9
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I'm riding an almost 20 yo aluminum frame with bonded joints. I tip the scales at about 240#. Am I scared of imminent failure? No.
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Old 09-06-08, 06:08 AM   #10
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Carbon Fiber failure is catospheric if it happens. It does not go into flex, stress, or bend mode prior to failure. It goes directly to severe strain break. A micro-second time span. It is not a malluable material which gives slightly like metals.

I have a full carbon fiber road bike and a 50/50 one (main tri is Aluminum, rest CF) and I check my seat tube on a regular basis.
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Old 09-06-08, 12:11 PM   #11
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Those older CF frames are lugged. Sometimes with age the tubes become unglued from the aluminum lug. If all is tight ride on.
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Old 09-06-08, 12:43 PM   #12
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"I'm riding an almost 20 yo aluminum frame with bonded joints. I tip the scales at about 240#. Am I scared of imminent failure? No."

Me too. Is yours a Vitus or Alan?

My Vitus 979 (Silver Wedding Anniversary present from my wife - it's slver coloured - bless her!)

- Is the lightest thing I've ever ridden - 16lbs dead, including pedals, bottle & cage and computer - with a full Chorus 9 speed gruppo, SLK carbon saddle and Arayo clincher rims - what a machine!
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Old 09-06-08, 01:09 PM   #13
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Quote:
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Those older CF frames are lugged. Sometimes with age the tubes become unglued from the aluminum lug. If all is tight ride on.
Yep, the failure will be at the lugs.
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