Singlespeed & Fixed Gear - Drilled-through Carbon Fiber? Deathwish?

http://i59.photobucket.com/albums/g304/firstflightbikes/eBay/epic5.jpg

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#.

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.

it will work just fine till you hit a bump too hard and the rear triangle snaps off completely

Yeah that looks really scary. Probably a sweet ass older frame though.

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)

Looks clean, but considering carbon's tendency to splinter...

all that for a brake.... =P

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.

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.

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.

I'd ride it until it failed catastrophically.

**** it man, we're not gonna live forever.

**** it man, we're not gonna live forever.

Be that as it may, I think most of us would still rather go without a splintered CF chainstay skewering our kidney.

http://photos1.blogger.com/blogger/5125/701/1600/moon%20whalers.0.jpg

"I died doing what I loved"

http://photos1.blogger.com/blogger/5125/701/1600/moon%20whalers.0.jpg

"I died doing what I loved"

riding a janky ****ing bike taht was doomed to failure

Even I, master of janky-assed-****, wouldn't touch that.

I'd ride it until it failed catastrophically.

**** it man, we're not gonna live forever.

Wait, let me get the video camera...

Az

it will work just fine till you hit a bump too hard and the rear triangle snaps off completely

+1, also, why do you think the orig owner is selling it? :rolleyes: cause he knows that bike is marked for death ;)

**** yall, ride that ****, show how hard you are

**** yall, ride that ****, show how hard you are

He'll find out how soft he is if he take's your advise and that frame splinters underneath him.

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.

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.

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.

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?

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.

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.

This is because the guy with the fancy CAD machine says "hey, what happens if we cut holes here? oh, we're going to have to add some material."

Not when the guy with the fancy craftsman drill machine says "hey, i'm just going to cut this **** without thinking"

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.

ahem


TED SHRED IT!!!!

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?

what's a bottom tube? Down tube, Chainstay, or BB shell? Most of those bikes have full Al headtubes and on those that don't have Al lugs in the only place a pebble from road is going to hit.

I say they kind of suck because they are floppier then spaghetti cooked by grandmother, the glue used at the lugs sucks and they weren't properly UV shielded. The seatstays however probably will last because:
1. they've lasted so far.
2. seatstays aren't under a huge amount of force in a direction that that drilling would severely weaken them except when braking.
3. If they do crack it probably won't be catastrophic.

How do you think they mount brakes now? Or waterbottle cages, for that matter. Specialized also warranties their frames for life.

they mount brakes now by designing aluminum or carbon drillable (or pre-drilled) inserts and incorporating them into the carbon weave's design, they don't just take a drill to carbon tubes.

the lifetime warranty only applies to the original owner. and even then they wouldn't warranty a frame that some jackass took a drill to. no matter what material it is.

edit: misread a post.


Edit #2. Nevermind, misread the OP. The original owner was a moron and you shouldn't touch it.

Buy it, ride it, shred it, and then you'll have a sweet story to tell other ssfg hipsters. If you're lucky, you'll even impress some hottie who happens to be watching when it collapses on you.