Second hand carbon frame bike

Red_Open

I'm looking at getting a second hand bike. Saw what looks like a good bike within my budget but before I make an offer on it I was wondering what people think of buying second hand carbon bikes. From the photos I can see a small bit of damage to the shifters. Which leads me to question whether or not the frame is damaged. Its quite far away from me so I'm wondering is this a run fast ,run far scenario or is it worth having a look at?
Cheers

07Lapierre

A damaged shifter does not mean the frame is damaged. Carbon frames are pretty robust. Carbon tends to fail catastrophicly once it's damaged, so unless the frame is in two halves, it's probably OK. But, as with all 2nd hand purchases, if you have any doubts, don't buy it.

omri

Could you expand on that damaged shifters? I got some markings on my shifters just from handling the bike in tight spaces but I never crashed on the bike.

If youre buying on adverts I guess its worth checking the sellers feedback page, comments and sold/withdrawn ads. This should give you an overall picture of the seller and allow you to make more conscious decision. If its possible to inspect the bike take your time and ask for the bike to be clean so it should be easier to see any damage.

Finally if the deal is too good to be true then chances are there is something wrong or you might be buying a stolen goods.

Brian?

Carbon is not fragile. As previously said, when it goes it usually goes big. Just give it a decent inspection.

Do you have a link to the pics or the ad?

monkeyslayer

Should be ok, just do a thorough inspection of the paintwork looking for cracks and warping... as with any second hand bike, especially of the higher end variety with more expensive groupsets I'd have a bit of extra cash ready for fixing it up, usually small problems with things like bearings, cables, springs going in derailleurs etc etc inevitably arise pretty soon after purchase. Don't assume the guy selling you the bike knows what he's doing.

Lumen

Turn the bike upside down and check for damage around the BB from dropped chains.

Red_Open

Thanks for all the replies. I can't link the ad as I don't have enough posts. I'll give it a good check alright. Is there anything specific to look out for? I'm relatively new to cycling. Crashed my bike a few weeks ago, writing off the frame. The rest of the parts were fine so I'll be keeping them as a back up.

Sarz91

Brian? wrote: »

Carbon is not fragile. As previously said, when it goes it usually goes big. Just give it a decent inspection.

Do you have a link to the pics or the ad?

Carbon Fibre can be pretty fragile. Steel and aluminium are isotropic materials, meaning they have the same physical properties in different directions. This is not true of carbon fibre as it is a composite material.

As to failure in Carbon bikes, it tends to be catastrophic but that doesn't mean it always is. Hairline cracks still occur in carbon, very often where carbon meets aluminium in either the frame or fork although this is not always the case. Carbon steerers very often suffer from hairline cracks from over torquing stem bolts. This can and sometimes does result in catastrophic failure while on the bike.

The idea that any of us can give someone advice as to whether or not the bike is safe to ride based on a few pictures of the bike seems crazy and borderline negligent. Why is it that we can give advice on whether or not a bike is safe to ride but we can't give medical advice? Unless the crack is completely obvious, surely medical advice and giving advice on the bike's structural integrity are one and the same.

Brian?

Sarz91 wrote: »

Carbon Fibre can be pretty fragile. Steel and aluminium are isotropic materials, meaning they have the same physical properties in different directions. This is not true of carbon fibre as it is a composite material.

As to failure in Carbon bikes, it tends to be catastrophic but that doesn't mean it always is. Hairline cracks still occur in carbon, very often where carbon meets aluminium in either the frame or fork although this is not always the case. Carbon steerers very often suffer from hairline cracks from over torquing stem bolts. This can and sometimes does result in catastrophic failure while on the bike.

The idea that any of us can give someone advice as to whether or not the bike is safe to ride based on a few pictures of the bike seems crazy and borderline negligent. Why is it that we can give advice on whether or not a bike is safe to ride but we can't give medical advice? Unless the crack is completely obvious, surely medical advice and giving advice on the bike's structural integrity are one and the same.

Carbon fibre is incredibly strong. But that's not really what the OP was asking.

The OP wanted to know if the damage to the hoods indicated the frame might be damaged. It doesn't. That's the question that's being answered. I have no idea if the bike is safe to ride, but I'd go and have a look at it based on the pictures in the ad. The reason I can give that advice and not advice on how to treat cancer is because it's common sense advice, no one goes to college for 7 years to learn to identify damage to carbon bike frames.

By your logic, no one should buy a carbon frame without subjecting it to an MRI.

Sarz91

Brian? wrote: »

Carbon fibre is incredibly strong. But that's not really what the OP was asking.

The OP wanted to know if the damage to the hoods indicated the frame might be damaged. It doesn't. That's the question that's being answered. I have no idea if the bike is safe to ride, but I'd go and have a look at it based on the pictures in the ad. The reason I can give that advice and not advice on how to treat cancer is because it's common sense advice, no one goes to college for 7 years to learn to identify damage to carbon bike frames.

By your logic, no one should buy a carbon frame without subjecting it to an MRI.

I don't remember saying don't buy a carbon frame. All I'm saying is if you are buying one, get one from someone serious about quality. http://road.cc/content/news/52205-canyon-proud-their-new-ct-scanner-their-what

"Give it a decent inspection." I'm sorry but unless the crack is blatantly obvious it's a bit pointless. How are you going to see something that Canyon have had to bring in a CT scanner for?

I understand what you're saying and I'm not trying to have a go at you or anyone else in here but the idea that if there are no visible cracks it should be grand is just wrong. The OP asked for advice. I'm giving mine.

No, they probably don't go to college for 7 years to identify damage to carbon bikes but I did study Material Science for 4 so I know a small bit about carbon or at least I pretend to.

NLC1072

The best thing to do is to check every inch of the frame for any defects, if none then it should be ok... the second most important thing to do is to take a chain checker tool, a lot of second hand bikes are sold when their chains have worn the gears to smithereens... expensive repair so they sell and get a new bike.

Invest in a chain tool so you dont get caught out. Ultegra or 105 group set could cost you more than you pay for the bike!!