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Old 04-09-06, 11:05 AM   #1
Jared88
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Carbon steerer tube scratches

Hi , when i was changing my stem today i found a few scratches on my steerer tube. There is a particularly long one which is deeper than the others. The scratches are very shallow but deep enough so that i can feel them when i rub the tube with my finger. Since this is a carbon steerer tube i am worried about cracks developing and eventual failure. I read somewhere that carbon products may fail if the scratch is beyond a certain length in deepness. Please advise.
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Old 04-09-06, 11:33 AM   #2
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What direction do the scratches run? If they are lengthwise along the steerer tube they probably aren't a hazard since, at worst, they will cause the steerer to split lengthwise. Not good but it won't cause a catastrophic accident. If thete is a deep crosswise scrarch, I'd be concerned since a fracture across the steerer tube will be very serious.

You might want to contact the fork's manufacturer for a better judgment call.
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Old 04-09-06, 11:39 AM   #3
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Quote:
Originally Posted by HillRider
What direction do the scratches run? If they are lengthwise along the steerer tube they probably aren't a hazard since, at worst, they will cause the steerer to split lengthwise. Not good but it won't cause a catastrophic accident. If thete is a deep crosswise scrarch, I'd be concerned since a fracture across the steerer tube will be very serious.

You might want to contact the fork's manufacturer for a better judgment call.
Uh oh...the scratches are crosswise. Here's a pic.

Last edited by Jared88; 09-18-06 at 11:18 PM.
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Old 04-09-06, 11:58 AM   #4
kenhill3
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Originally Posted by HillRider
What direction do the scratches run? If they are lengthwise along the steerer tube they probably aren't a hazard since, at worst, they will cause the steerer to split lengthwise. Not good but it won't cause a catastrophic accident. If thete is a deep crosswise scrarch, I'd be concerned since a fracture across the steerer tube will be very serious.

You might want to contact the fork's manufacturer for a better judgment call.
Makes plenty of sense in this asessment of the scratch (radial versus longitudinal) as to potential failure. That said, it would be good to go beyond speculation or hearsay, and hear from someone who has had the experience of a faiure. My only even remotely similar circumstance was with CF MTB bars in a crash on a trail ride. The bar did indeed break (near the stem), but the fibers held together enough so that I could ride back via fire road. CF is not glass, therefoire unlikely to separate completely.
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