Drilled-through Carbon Fiber? Deathwish?
12-09-07, 06:38 PM
#1
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Drilled-through Carbon Fiber? Deathwish?
on an older carbon frame (think aluminum lugs)
would this be just asking for trouble?
the original owner drilled through the tubes to keep the brake bridge attached securely.
i'm wondering if it'll hold my 150#.
12-09-07, 06:40 PM
#2
Beausage is Beautiful
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I wouldn't ride it, but I also just don't like bonded frames. If those holes were there from the factory, that would be one thing, but if they were added by the prior owner I wouldn't trust it.
12-09-07, 07:17 PM
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veggieburglar
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Yeah that looks really scary. Probably a sweet ass older frame though.
12-09-07, 07:29 PM
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Mo' Senior
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I don't think the brake bridge would have held your weight regardless of the drilling ...
heh heh heh.
(Oh yeah, I probably wouldn't ride it, unless you have that section inspected/beefed up by someone like Calfee--I think they do carbon repairs)
heh heh heh.
(Oh yeah, I probably wouldn't ride it, unless you have that section inspected/beefed up by someone like Calfee--I think they do carbon repairs)
12-09-07, 07:33 PM
#6
crotchety young dude
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Looks clean, but considering carbon's tendency to splinter...
12-09-07, 07:45 PM
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There are two things likely to happen. One: Stress fractures around the bridge make the frame unrideable. Or two, you slam the brakes, the rear triangle snaps and you go flying through the intersection if you havent fallen already.
12-09-07, 07:54 PM
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Failure is imminent with that thing
it might be saved by engineering a metal collar (2 piece lugs) for both
stays and bonding them to the assembly. a frame expert
could do it.
it might be saved by engineering a metal collar (2 piece lugs) for both
stays and bonding them to the assembly. a frame expert
could do it.
12-09-07, 08:23 PM
#10
It's an old photo
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I would not ride that thing no matter the price. Those are really thin CF stays to start with, and even drilling aluminum like that would make me nervous. Coupled with the forces that thing undergoes during braking (lets see.. F=ma. If you and the bike weigh 165lbs, that's 75kg. Let's say you're going 25mph (11.2 m/s) and want to slow to a stop over 3m (~10ft) in an emergency. That's an average negative acceleration of 20.9 m/s/s. Plug it back in, and you get 1568 N exerted on those two little seatstays.. those are a lot of newtons, my friend. It would be roughly equivalent to a guy twice your weight standing on them, but while wearing ice skates because the contact surface area is so small.) I wouldn't be surprised if they cracked eventually.
Sorry, I've been studying a lot of simple physics recently.
You know, if you're riding it fixed you likely won't be using a rear brake.. well either way, I wouldn't trust it.
Sorry, I've been studying a lot of simple physics recently.
You know, if you're riding it fixed you likely won't be using a rear brake.. well either way, I wouldn't trust it.
Last edited by Boss Moniker; 12-09-07 at 08:31 PM.
12-09-07, 10:03 PM
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cause he knows that bike is marked for death 
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12-10-07, 06:54 AM
#19
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He'll find out how soft he is if he take's your advise and that frame splinters underneath him.
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You see, their morals, their code...it's a bad joke, dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these...These "civilized" people...they'll eat each other. See, I'm not a monster. I'm just ahead of the curve
You see, their morals, their code...it's a bad joke, dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these...These "civilized" people...they'll eat each other. See, I'm not a monster. I'm just ahead of the curve
12-10-07, 06:57 AM
#20
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I would not ride that thing no matter the price. Those are really thin CF stays to start with, and even drilling aluminum like that would make me nervous. Coupled with the forces that thing undergoes during braking (lets see.. F=ma. If you and the bike weigh 165lbs, that's 75kg. Let's say you're going 25mph (11.2 m/s) and want to slow to a stop over 3m (~10ft) in an emergency. That's an average negative acceleration of 20.9 m/s/s. Plug it back in, and you get 1568 N exerted on those two little seatstays.. those are a lot of newtons, my friend. It would be roughly equivalent to a guy twice your weight standing on them, but while wearing ice skates because the contact surface area is so small.) I wouldn't be surprised if they cracked eventually.
Sorry, I've been studying a lot of simple physics recently.
You know, if you're riding it fixed you likely won't be using a rear brake.. well either way, I wouldn't trust it.
Sorry, I've been studying a lot of simple physics recently.
You know, if you're riding it fixed you likely won't be using a rear brake.. well either way, I wouldn't trust it.
I wouldn't be surprised if those stays lasted a pretty long time. I'm guessing the original owner didn't do that recently. I still woudn't buy it though not only because of the the stays but also because those old cf frames are pretty ****ty.
12-10-07, 07:47 AM
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Don't your calculations assume the lack of a front brake?
I wouldn't be surprised if those stays lasted a pretty long time. I'm guessing the original owner didn't do that recently. I still woudn't buy it though not only because of the the stays but also because those old cf frames are pretty ****ty.
I wouldn't be surprised if those stays lasted a pretty long time. I'm guessing the original owner didn't do that recently. I still woudn't buy it though not only because of the the stays but also because those old cf frames are pretty ****ty.
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You see, their morals, their code...it's a bad joke, dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these...These "civilized" people...they'll eat each other. See, I'm not a monster. I'm just ahead of the curve
You see, their morals, their code...it's a bad joke, dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these...These "civilized" people...they'll eat each other. See, I'm not a monster. I'm just ahead of the curve
12-10-07, 07:59 AM
#22
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The above statement tells me that you do know about early carbon frames but your contradicting yourself by saying,"I wouldn't be surprised if those stays lasted a pretty long time" then saying,"I still woudn't buy it though not only because of the the stays but also because those old CF frames are pretty ****ty." Im sure you know in the early years of CF frames everyone wondered why they were having headtube and bottom tube failures (amongst other faiures) then they found out that sand and small pebbles coming off of the front tire and hitting the bottom tube were causing micro fractures, and those tiny micro fractures were causing the bottom tube and headtube to splinter under stress, so what do you think drilling holes in the frame might do?
Bottom tube?
Anyway, holes in carbon fiber are just fine. How do you think they mount brakes now? Or waterbottle cages, for that matter. Specialized also warranties their frames for life.
12-10-07, 08:33 AM
#23
yeahh, becky
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Not when the guy with the fancy craftsman drill machine says "hey, i'm just going to cut this **** without thinking"
12-10-07, 09:38 AM
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fails just as quickly
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I have that same frame sitting right next to me with mostly stock shimano 600 components. It is a pretty "interesting" frame, but even without the dubiously directed drilling it is springy and noodley as hell. It's not a bad frame, but I don't know that I would recommend buying it (I got mine for free). Vintage carbon is not quite the same as vintage steel. The busted seatstays would be the deal-breaker.
