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Carbon fork evaluation

Old 05-02-19, 09:07 PM
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bonsai171
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Carbon fork evaluation

Is this fork safe to ride? It is a Forte Axis 1" threadless fork. Has some hairline marks where the blades meet the crown. The lines almost look like they should be there, but I'd like to get a second opinion.
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Old 05-02-19, 09:32 PM
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What I think I see are the boarders of the crown's sub assembly and the blades. It's not uncommon for the finish (or the under top finish putty) to be more brittle then the structure. The diagonal and lengthwise marks look more to be scratches then cracks. Have you had an experienced eye look at it in person? Andy.
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Old 05-03-19, 03:36 AM
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Thanks. No one has looked at it yet in person. Do you think my LBS would do that as part of a safety check? I would probably ask them to look at that specifically.

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Old 05-03-19, 06:30 AM
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Dave- I wouldn't expect any shop, or others, to notice these marks on your fork unless they are told first. I don't know under what service name the shop will list the inspection, our service list doesn't have a "safety check" on it. We do initial on the spot inspections for free, unless we need to take stuff apart to evaluate. But yes, a shop is a good first step in gaining knowledge and having a better founded opinion. Andy
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Old 05-03-19, 06:58 AM
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The only way to be certain with carbon parts is scanning (ultrasound for all I know, but check with an expert).

Visual inspection, or tapping won't reveal every flaw. Which would not be a problem if the failure mode was similar to metal parts: visible cracks on the outside that grow bigger before fully cracking. With carbon it's often relatively (or perfectly) fine on the outside, before it just snaps. Not trying to do any fear mongering - though it does boil down to that, unfortunately.

If you are the first owner and had no accidents, it's probably what it looks like: surface paint scratches and nothing more. Having said that, I ride without a helmet, but find (potentially) faulty fork an unacceptably high risk. Scanning is expensive, but not as much as repairs.
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Old 05-03-19, 10:27 AM
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Looks like a joint line to me as well, from the solid fork crown to the hollow CF fork tubes. Coin tap not likely to help because of
the abrupt change from solid to hollow. Strictly the crown may not be solid but so much more beefy than the fork tube as to be
solid like.

OTOH, I always wonder about the two CF bars I have, both of which had usage leaflets that recommend changing the bar after 3 yrs use.
I have installed only two CF forks in the last 25yrs, neither of which came with 'instructions'.
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Old 05-03-19, 10:57 AM
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I doubt many shops are going to tell you cracked CF parts, no matter how minor, are safe to continue riding. Why would they accept the liability? Better for them to play it safe. (and sell you new parts)
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Old 05-03-19, 11:24 AM
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Originally Posted by AlmostTrick View Post
I doubt many shops are going to tell you cracked CF parts, no matter how minor, are safe to continue riding. Why would they accept the liability? Better for them to play it safe. (and sell you new parts)
It's not about the money, not with carbon, definitely not with forks. It's about sleeping well at night. Failure mode is often unpredictable (sudden) and total ("catastrophic").

Also, by declaring something as "good to go" when others have recommended a (n expensive) replacement, one can often gain customers. I've seen it.


When in doubt, for me the reality check method is: "would I let my kid ride this?" - and I'm not a parent that doesn't encourage climbing trees and walls and all the other good stuff. So, at least for me, recommendations are always "to the best of my knowledge".


This is all completely disregarding the law, suits and liabilities (which practically don't apply for my country, but for all I know are something to also worry about for most of the USA and EU, so bike shops most probably have that in mind when giving recommendations).

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Old 05-03-19, 11:24 AM
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Carbon fiber bike parts have limited life and are disposable. That's a feature that costs extra.
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Old 05-04-19, 06:49 AM
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If it was mine, I'd replace the fork. My peace of mind and enjoying my ride is worth more than constantly worrying about whether my fork will fail while I'm riding.
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Old 05-04-19, 08:46 AM
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Always nearly impossible to diagnose CF cracks on the net. Given the facts, 1" steerer, Forte brand, would suggest this an old, low end model?? and maybe just due for replacement but as mentioned needs some expert, in person and/or special equipment to diagnose properly.
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Old 05-04-19, 06:59 PM
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Bonding lines where the metal crown and the carbon fork blades are joined. When new, the joint line is bonded over with a filler, painted with a black fade, then clear coated.
I have repainted a couple of bikes with like joints not only there, but also at the tips of the fork where the insert to retain the wheel, and the carbon rear stays to the bottom bracket/seat tube joints. They haven't assploded, yet.

I think there are a lot of bikes like this, out there.

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