Crack or paint: Cervelo R5, very thin seat stays

[Fudgesicles5]

Hey guys,

New to this forum, joined looking for lightweight tips and just general cycling discussion.

Anyways,I was cleaning my 2012 Cervelo R5 with 1100 miles of riding on it and noticed a paint chip about 3mm x 10mm at the front of the seat stays, facing the seat tube; quite a peculiar spot to find a paint chip to be honest. Bike has never been crashed, and I'm unsure what could have caused it storage wise.

At first glance it looked purely like a paint chip, but upon taking some photos with better lighting, it seems a little more suspect, I'm honestly not 100% sure.

First of many posts to come on this forum! Thanks in advance for the help! Really appreciate it!

[dfischer1]

Looks like clearcoat/paint only. Any difference with the coin tap test? I would inspect after the next couple rides.

[justonwo]

That just looks like a paint chip to me. Perhaps you inadvertently hit the seat stay against something without realizing it? My kids have knocked my bikes over and created mystery damage (like a bent derailleur hanger).

[Fudgesicles5]

Looks like clearcoat/paint only. Any difference with the coin tap test? I would inspect after the next couple rides.

Tried the tap test but couldn't really differentiate the sounds. It all sounds quite dull there unfortunately all along the seat stay. Interestingly enough, Cervelo drilled two tiny holes on each seat stay near the bottom closer to the drop out during the manufacturing process to let air escape during heating process, so there are already two holes on the seat stays. I've heard from industry literature online from some Cervelo engineers that these stays were there only to mount the rear brake and adhere to UCI regulations. Other than that, you can supposedly hank off the seat stays and still ride the bike. Quite insane, but I won't be doing that anytime soon and will definitely be watching it.

[Fudgesicles5]

That just looks like a paint chip to me. Perhaps you inadvertently hit the seat stay against something without realizing it? My kids have knocked my bikes over and created mystery damage (like a bent derailleur hanger).

Does seem like a chip for sure, but the only concerning thing was that the layer that is exposed by the chip also seems quite scratched up which made me suspect. Could just be some resin or expoxy scratched? I don't see any fibres splintering and it doesn't cave in when I press on it with some substantial force. Luckily the forces on those stays are compression only, they're not really there to support rider weight and riding forces. I'm just shocked how Cervelo were able to design them so incredibly thin when the industry standard at the time was going to thicker diameter and more aero tubes.

[Alexbn921]

I would lightly sand the area with 2000 grit and use some clear nail polish to fill it in.

[Fudgesicles5]

I would lightly sand the area with 2000 grit and use some clear nail polish to fill it in.

Thanks Alex, I'll plan to do that. Thinking about getting it inspected by the carbon repair shop near my area, but with this covid stuff they seem loaded with work after closing down for a couple months.

[F45]

Grab it and give it a hearty flex and if it cracks more, it was a crack.

[1415chris]

If this is a paint chip, it is very strange one. The pictures are not clear enough however to me it looks more like proper scratch, where clear coat, paint and primer were taken off to the bare carbon. If you cannot see any further damage, apart ugly scratch, no reason to worry about.

[Fudgesicles5]

Grab it and give it a hearty flex and if it cracks more, it was a crack.

I'm planning on taking it out for some rides to see if the bare carbon underneath changes. Luckily that area receives the least amount of force and there is a video of a shop cutting the seat m stays off a 2009 R3SL and still riding it around the block.

[Fudgesicles5]

If this is a paint chip, it is very strange one. The pictures are not clear enough however to me it looks more like proper scratch, where clear coat, paint and primer were taken off to the bare carbon. If you cannot see any further damage, apart ugly scratch, no reason to worry about.

It is indeed very strange. This is the 2012 Cervelo R5 Argyle LTD edition with the Cervelo-Garmin colours. It's supposed to be 79 grams lighter or something with less paint, so maybe that's why it's able to scratch so easily to the bare carbon? My understanding is that carbon doesn't usually crack in that sort of pattern unless it was some kind of chain suck on the bottom bracket which I've seen on the early S2 models where the BB and crank spacing was extremely narrow. From photos online, it seems to crack in a jagged line pattern. The scratch I have is literally inside the seat stay, facing the seat tube. You wouldn't be able to see it from the outside. The only reason I found out was when I was running a towel over it and felt the inside, what I thought was grime or rough dirt at first was actually a pretty large scratch.

[Fudgesicles5]

Here's a higher res photo of it

[JMeinholdt]

Maybe I'm in the minority, but it looks like the fibers are splintering in the chipped area. At any rate, if you plan to ride it, I'd look to get some carbon fiber epoxy resin and brush a thick coating on the area to fill it in.

[froze]

When you did the coin tap test did you also test the other stay on the opposite side to see if it sounded like the stay with the paint taken off? you have to compare one stay with the other to get a sound difference, if there is a sound difference then you potentially have a problem.

The picts are kind of weird, no fault of yours, it's what photos do, but it does appear to be small strands of fiber poking about, or it could be fine scratches on the paint that make it look like strands of fiber in the pics.

[eric01]

Nail polish and ride. Inspect it periodically. Won’t notice any difference