Is this damage to carbon fiber bad?
#1
pluralis majestatis
Thread Starter
Join Date: Feb 2004
Location: you rope
Posts: 4,206
Bikes: a DuhRosa
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 537 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
Is this damage to carbon fiber bad?
bottom bracket... area looks thick and stiff... dont think this dislocation point (under the tape) is bad enough to grow and deform ... but i could be wrong
#4
Senior Member
Join Date: Jul 2011
Posts: 99
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
#5
Making a kilometer blurry
#6
Senior Member
For what it's worth, even if the frame fails catastrophically at that location, I don't think it would result in a catastrophic crash or anything. I might ride it with that consideration alone, but that's just me.
__________________
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter
#7
Administrator
Join Date: Feb 2005
Location: Delaware shore
Posts: 13,557
Bikes: Cervelo C5, Guru Photon, Waterford, Specialized CX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1105 Post(s)
Liked 2,169 Times
in
1,461 Posts
Maybe the tape keeps it from cracking more
#8
Senior Member
Join Date: Dec 2004
Location: SoCal Baby
Posts: 2,137
Bikes: o5 Specilized roubaix Comp, 06 Tequilo
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
tap the area with a quarter . if you hear clicks you are golden. if you here any clunks you are f****d. what is the tape for?
#9
Senior Member
Join Date: Dec 2010
Posts: 113
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
A crack will continue to propagate in a FRP structure. the hole drilling technique is a cross over from metal workers ( and not recommended for plastics). To keep the region from further stress, it's really easy, apply an epoxy topcoat using some form of fibre for reinforcement. could be carbon, or even an e glass 6 or 10 oz cloth would be sufficient.
Now if aesthetics are top priority, then the region must be scarfed first, then the patch overlay applied and then faired smooth. but its on the bottom, patch it and ride.
Now if aesthetics are top priority, then the region must be scarfed first, then the patch overlay applied and then faired smooth. but its on the bottom, patch it and ride.
#10
Making a kilometer blurry
I believe cracks are self-terminating in fiber reinforced plastic composites; in other words, the crack will not spread due to fatigue - doesn't mean it won't unzipper (means just like it sounds) catastrophically under heavy overload. Drilling the crack ends are usually to prevent fatigue propagation in metals. While you are relieving the stress concentration, you are losing material and I'm not sure that's a good thing to prevent a catastrophic failure. But again, we are all looking at a picture; if the OP can't come to the decision on his own to ride it or not, best to send it to a qualified bike shop. Might send the picture to a composite's shop like Calfee who has experience evaluating these things. With a crack like that in that area, there might be more damage in the carbon fiber structure that is not visible.
For what it's worth, even if the frame fails catastrophically at that location, I don't think it would result in a catastrophic crash or anything. I might ride it with that consideration alone, but that's just me.
For what it's worth, even if the frame fails catastrophically at that location, I don't think it would result in a catastrophic crash or anything. I might ride it with that consideration alone, but that's just me.
A crack will continue to propagate in a FRP structure. the hole drilling technique is a cross over from metal workers ( and not recommended for plastics). To keep the region from further stress, it's really easy, apply an epoxy topcoat using some form of fibre for reinforcement. could be carbon, or even an e glass 6 or 10 oz cloth would be sufficient.
Now if aesthetics are top priority, then the region must be scarfed first, then the patch overlay applied and then faired smooth. but its on the bottom, patch it and ride.
Now if aesthetics are top priority, then the region must be scarfed first, then the patch overlay applied and then faired smooth. but its on the bottom, patch it and ride.
So, yeah, doesn't seem to help with fiber stuff
Looking at the bottom of the BB shell though, there is a hole in it already. Any thoughts as to if that was drilled at the factory, or molded in?
#11
Artificial Member
Join Date: Jan 2010
Location: Cyberspace
Posts: 7,158
Bikes: Retrospec Judd, Dahon Boardwalk, Specialized Langster
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 6759 Post(s)
Liked 5,466 Times
in
3,215 Posts
I think that will buff right out.
__________________
#14
L-I-V-I-N
Join Date: May 2005
Location: Stafford, OR
Posts: 4,796
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
OP - are you the original owner? That is a Trek, correct?
__________________
"The older you do get, the more rules they're gonna try to get you to follow. You just gotta keep livin', man, L-I-V-I-N." - Wooderson
'14 carbon Synapse - '12 CAAD 10 5 - '99 Gary Fisher Big Sur
"The older you do get, the more rules they're gonna try to get you to follow. You just gotta keep livin', man, L-I-V-I-N." - Wooderson
'14 carbon Synapse - '12 CAAD 10 5 - '99 Gary Fisher Big Sur
Thread
Thread Starter
Forum
Replies
Last Post
aprhockey
Framebuilders
8
05-25-12 11:07 AM