Used Carbon forks - how to assess?
We had someone come by our shop this weekend. They had just bought a Specialized Allez from the early 2000s with a used carbon fork. They wanted to know if it the carbon fork was safe. None of us at the shop at the time have a ton of knowledge for what to look for... we suggested:
- Email the fork manufacturer to ask if there were any recalls
- Look for signs to see if the bike may have been in a crash and any clear
signs that the fork may be damaged 3. Take the fork out to inspect the steerer tube and look at the races
Any other advice, yall? Thanks for your assistance!
-Laura (volunteer at Freeride Montpelier)
With the fork out of the bike held by the steer tube on a soft surface give it a wump, and then listen to the ring. A damaged fork will be daul and could even buzz or rattle whereas a sound fork will like a tuning fork sound solid and clear
On Sun, May 7, 2023 at 9:24 AM Laura Brooke via TheThinkTank < thethinktank@lists.bikecollectives.org> wrote:
We had someone come by our shop this weekend. They had just bought a Specialized Allez from the early 2000s with a used carbon fork. They wanted to know if it the carbon fork was safe. None of us at the shop at the time have a ton of knowledge for what to look for... we suggested:
- Email the fork manufacturer to ask if there were any recalls
- Look for signs to see if the bike may have been in a crash and any
clear signs that the fork may be damaged 3. Take the fork out to inspect the steerer tube and look at the races
Any other advice, yall? Thanks for your assistance!
-Laura (volunteer at Freeride Montpelier) _______________________________________________ TheThinkTank mailing list -- thethinktank@lists.bikecollectives.org To unsubscribe send an email to thethinktank-leave@lists.bikecollectives.org To view this discussion on the web visit https://lists.bikecollectives.org/hyperkitty/list/thethinktank@lists.bikecol...
Laura Brooke-
Your advice is very good. I have experience in carbon fiber bicycle repair and construction. If there are no manufacturing defects, any damage should be visible. However, it can be a little difficult to determine the extent of the damage visually. One common method to determine structural integrity is to tap the structure with a wooden dowel/peg. Uncompromised composite structures will ring; cracked/delaminated/compromised structures will sound flat or even have a slight buzz. You can compare the questionable structure tone to a known uncompromised structure(s) to compare tones. This is not perfect, but with some practice on different samples, a tech can get quite good at analysis. The gold standard for carbon analysis are radiographs and sonograms, but those are not practical in most bicycle repair applications.
Kevin Dwyer
On May 7, 2023, at 5:24 PM, Laura Brooke via TheThinkTank thethinktank@lists.bikecollectives.org wrote:
We had someone come by our shop this weekend. They had just bought a Specialized Allez from the early 2000s with a used carbon fork. They wanted to know if it the carbon fork was safe. None of us at the shop at the time have a ton of knowledge for what to look for... we suggested:
- Email the fork manufacturer to ask if there were any recalls
- Look for signs to see if the bike may have been in a crash and any clear signs that the fork may be damaged
- Take the fork out to inspect the steerer tube and look at the races
Any other advice, yall? Thanks for your assistance!
-Laura (volunteer at Freeride Montpelier) _______________________________________________ TheThinkTank mailing list -- thethinktank@lists.bikecollectives.org To unsubscribe send an email to thethinktank-leave@lists.bikecollectives.org To view this discussion on the web visit https://lists.bikecollectives.org/hyperkitty/list/thethinktank@lists.bikecol...
Jim, and Kevin: Thanks SO much for this great advice! We have been struggling with this issue and are currently NOT selling carbon *anything*, so this may change that decision.
Kevin, can you recommend any resources on this topic? We have asked around the local cycling community and even spent an evening social at CABDA picking the brain of "The Carbon Doctor" and never heard of this sensible test.
Laura, thanks to you too, for asking the question! Why we didn't think to just ask the 'Tank, I do not know!
Peace, Jim
Jim Sheehan Executive Director Ohio City Bicycle Co-op 1840 Columbus Rd Cleveland, Ohio 44113 216 830 2667 OhioCityCycles.org jim@ohiocitycycles.org
On Mon, May 8, 2023 at 3:22 AM Kevin Dwyer via TheThinkTank < thethinktank@lists.bikecollectives.org> wrote:
Laura Brooke-
Your advice is very good. I have experience in carbon fiber bicycle repair and construction. If there are no manufacturing defects, any damage should be visible. However, it can be a little difficult to determine the extent of the damage visually. One common method to determine structural integrity is to tap the structure with a wooden dowel/peg. Uncompromised composite structures will ring; cracked/delaminated/compromised structures will sound flat or even have a slight buzz. You can compare the questionable structure tone to a known uncompromised structure(s) to compare tones. This is not perfect, but with some practice on different samples, a tech can get quite good at analysis. The gold standard for carbon analysis are radiographs and sonograms, but those are not practical in most bicycle repair applications.
Kevin Dwyer
On May 7, 2023, at 5:24 PM, Laura Brooke via TheThinkTank <
thethinktank@lists.bikecollectives.org> wrote:
We had someone come by our shop this weekend. They had just bought a
Specialized Allez from the early 2000s with a used carbon fork. They wanted to know if it the carbon fork was safe. None of us at the shop at the time have a ton of knowledge for what to look for... we suggested:
- Email the fork manufacturer to ask if there were any recalls
- Look for signs to see if the bike may have been in a crash and any
clear signs that the fork may be damaged
- Take the fork out to inspect the steerer tube and look at the races
Any other advice, yall? Thanks for your assistance!
-Laura (volunteer at Freeride Montpelier) _______________________________________________ TheThinkTank mailing list -- thethinktank@lists.bikecollectives.org To unsubscribe send an email to
thethinktank-leave@lists.bikecollectives.org
To view this discussion on the web visit
https://lists.bikecollectives.org/hyperkitty/list/thethinktank@lists.bikecol... _______________________________________________ TheThinkTank mailing list -- thethinktank@lists.bikecollectives.org To unsubscribe send an email to thethinktank-leave@lists.bikecollectives.org To view this discussion on the web visit https://lists.bikecollectives.org/hyperkitty/list/thethinktank@lists.bikecol...
participants (4)
-
Jim Bledsoe -
Jim Sheehan -
Kevin Dwyer -
Laura Brooke