Lugged carbon frame... Is it safe?

I recently bought a carbon road frame. It is a beauty of a frame. Feels really solid but is quite light at the same time. It was a bargain.

Thing is, it was made in the early 90s, but wasn't used very much so it is in good condition. I think the aluminium lugs are quite solid as they don't feel hollow when tapped.

Someone recently warned me about the risk of carbon tubes unbonding from the lugs. I am starting to get worried about that - what if I'm going downhill at 35mph and it falls apart?!

The one small thing i noticed was a bit of bubbling and cracking of the resin (which runs over the aluminium too) at the boundary between the carbon and the aluminium lugs but its only noticeable close up, Can this be fixed? (the aluminium doesn't show any white deposits though so presumably hasn't corroded)

Are my fears irrational as I am getting tempted to get rid of it even though there are no apparent problems! The bike is a Giant 980c... Anyone heard of it? Are there any reported problems with these?

Thanks in advance for any help,
Mike

Email Giant with your concerns, they are a large and established bike company and am sure would answer any concerns you have.

If you want shot of it, i know someone who would be interested.
I doubt, however, that you will have any problems with the frame un-bonding.

Chris

i doubt the resin will be a problem

i have some carbon forks with the resin put all over them, its slowy wearing its way off the aluminium ends but is like shit on a blanket over the carbon.

so i think (ha) that the resin plays no part really in the strengh of the alu and its probably done more for convinience etc.

I dont know anything in particular about carbon frames and such, Id reccommend what tynan said about that.

But just regarding that comment you made about white deposits on aluminium/corrosion.

The whitish residue you get on aluminium is belive it or not a perfectly fine thing.

It is very thin and superficial, unlike rust, it actually protects the metal from being corroded any further.

how is he so clean after that happening

how is he so clean after that happening

Staged publicity shot for a bike company not called Merida?

bump. Thinking about my next project, which might be a carbon conversion. Chatting to hilbilly tonight, we came up with the following problem: Road frames aren't made to handle the "pull" stress on the rear triangle when braking (fixed). What are the chances I'd pull the dropout out, or tear the rear triangle (because it's a road frame, it is designed to take a compression force but not a "tension" force).

am I worrying unnecesarily?

Yes.

Ride it until it or you dies.

is there any data to support the hypothesis that 'pull' forces are greater than 'push' forces?
just asking, not arguing, but i would say that my quads + hamstrings + glutes (pushing) are more powerful than my hip flexors (pulling).

put it this way: i can accelerate from 0-20km/h faster than i can decelerate from 20-0km/h, i think.

Yeah but locking the wheel it becomes the force of the body+bike on the road or some shit innit? Where's the Tommy?

bump. Thinking about my next project, which might be a carbon conversion. Chatting to hilbilly tonight, we came up with the following problem: Road frames aren't made to handle the "pull" stress on the rear triangle when braking (fixed). What are the chances I'd pull the dropout out, or tear the rear triangle (because it's a road frame, it is designed to take a compression force but not a "tension" force).

am I worrying unnecesarily?

also: half of the frames people ride here are fixed conversions based on road frames - it's not a problem for them. it's really nothing to do with whether it's a road frame... you're worrying about the carbon fibre.

carbon is stronger than you are.

Speak for yourself skinny.

(It's true though :))

Yeah but locking the wheel it becomes the force of the body+bike on the road or some shit innit? Where's the Tommy?

nah cos if you lock the wheel (which usually happens mid-bunny hop in a skid) the forward momentum of your body weight + bike is actually just being slowed by the tyre skidding over the road (ie friction between tyre and road), and the actual force applied to the rear triangle by your feet is bugger all (it's static).
i don't reckon there's actually that much force going through the rear triangle, cos the deceleration of the rear wheel is happening under very little load (it happens mid-air when you bunny-hop the rear wheel) as your body weight is not involved at that point.

am i barking up the wrong tree? does anyone have any actual force measurements from anywhere?

Speak for yourself skinny.

(It's true though :))

hippy called me skinny. fucking hooray!

you're worrying about the carbon fibre.

exactly. specifically, I'm worried about the weave being designed for compression forces but not for a tension force on the drive-side down-stay. i'm not worried about generating excessive force (braking vs accellerating). Chance would be a fine thing if I could do either..!

Well you're a runner.. aren't they all skinny fuckers? Hmm Ben Johnson.. okay maybe not.. but then anyone is skinny compared to me..

I think I get what you say above. Would the force applied to the rear triangle differ between rear wheel braking on a road bike and skidding when fixed? It's the same thing isn't it? In which case I'm sticking with my "it'll be fine ya wuss bag" answer.

I have some calcs at work. post em in a bit.

Menorida...
Fixed
(Unlike the bike)

it's Merida, they are shite

I agree with tynan

The whitish residue you get on aluminium is belive it or not a perfectly fine thing.

That's what hippy keeps telling me.
To be frank, I'm sceptical...

nah cos if you lock the wheel (which usually happens mid-bunny hop in a skid) the forward momentum of your body weight + bike is actually just being slowed by the tyre skidding over the road (ie friction between tyre and road), and the actual force applied to the rear triangle by your feet is bugger all (it's static).
i don't reckon there's actually that much force going through the rear triangle, cos the deceleration of the rear wheel is happening under very little load (it happens mid-air when you bunny-hop the rear wheel) as your body weight is not involved at that point.

am i barking up the wrong tree? does anyone have any actual force measurements from anywhere?

Close enough, I wouldn't be to worried about the the dropouts being pulled off by skidding since nearly all the force is transfered to the bottom bracket via the chain, not into the dropouts. I'd be skeptical about using an old Alum-carbon lugged job as they have a nasty habit of comming apart at the lugs, well the mountain bike ones I've seen did.

any bonded frame, aluminium (vitus) or carbon, i would stay clear of after 5+ years old

ok this is 2 years old and has only been used for one summer. It's a high quality frame, so I'm not expecting quality control issues.

badtmy makes a good point about skid-stopping, I think this deals with my concern. Pulling the dropouts out could happen to any frame, fixed or not...

Anyone ever had to repair dropouts on a carbon frame?