Road Cycling - Carbon Fiber seat stays

Would someone enlighten me as to the pros and cons of carbon seat stays? I would assume a more compliant ride, less flex?

Dax

95% arketing,5% benefit.CF damps small vibrations better than Ti or steel frame materials.Maybe of more benefit on Al frames than Ti or steeel.One cannot generalize about lighter, stiffer ,compliant or whatever,cause of all the other variables.

Although I've never ridden a frame that has carbon fiber seat stays, they're getting quite popular now. They're supposed to do the same basic job as a carbon fiber fork would do; they dampen road vibrations.

Now, I have a carbon fiber fork, and it is an improvement over other materials. This could definitely be the case with the seat stays, too. Worth the money? I don't know.

Pinarello prince has a carbon fiber seat stay, and have read the review on them, said it great,,,,

Yes, they are becoming rather common, and they must serve the same purpose as a CF fork I would guess. The connection between the frame metal and the carbon kinda makes me nervous...wonder if it's reliable?

Dax

I'm assuming that they are "bonded", "glued" or whatever. It works in airplanes.

They seem to ride well. It permits smaller builders to build almost-carbon bikes with variable/custom geometry, whilst saving on production and tooling costs.

The problem that I envisage, especially on aluminium frames is that for the seat stays to absorb any road shock then they must flex, to do this the chainstays must also flex, flex and aluminium don't really mix, al. has a limited fatigue life if flexed. Steel and Ti. stays would not be a problem however I see little need for these materials to have carbon seat stays.

I just bought a used DeRosa Planet that is aluminum with carbon stays. Now I'm thinking I should sell it before the frame cracks. Are you sure about the flex/fatigue thing? Thanks- Roger

In some, the carbon fibre unit is an entire rear end, chainstays, seatstays, dropouts, sold as a unit to the frame-builder. He just glues this onto his main triangle.
With the seat-stay only units, the alledged advantage is in the damping, not the structural stiffness.

The only significant problem is likely to be un-bonding of the join.

Originally posted by rhafe
I just bought a used DeRosa Planet that is aluminum with carbon stays. Now I'm thinking I should sell it before the frame cracks. Are you sure about the flex/fatigue thing? Thanks- Roger
I don't think I'd be worried about your frame cracking.
oh wait, I'ts probably cracking as we speak. . .
what size is the planet and if right I'll take it
off your hands for $50 and save you the medical
expenses :lol:

Marty

Yeah that frame is dangerous. You better sell it to me fast before it cracks!

Originally posted by rhafe
I just bought a used DeRosa Planet that is aluminum with carbon stays. Now I'm thinking I should sell it before the frame cracks. Are you sure about the flex/fatigue thing? Thanks- Roger

Sorry guys, but I've decided to keep it. I'll probably crack before the frame does.

Yes I think that you should keep it, I'm not saying that the frames are unsound structurally, I am sure that companies do lots of testing before releasing their frame (at least some of them but there are lots of carbon rear stays now). What I was hinting at however is that I don't understand how the stays can absorb shock without flexing the chainstays, ie do they actually work as claimed? I am sure that those who have ridden them are in a much better position to determine this than me. At this stage it seems like a marketting gimmick rather than something that is providing real benefit. Just my opinion, which is after all what a forum is about.

you're not understanding the purpose of carbon stays. Yes, they can be designed to flex like on the Cannondale Scalpel.

On road bikes, the stays DO NOT flex. Instead, it is the inherent vibration dampening quality of carbon that makes for a more comfortable ride. It also uses the characteristics of the material to create a different feel to a straight aluminum frame.
Despite aluminum's lower tolerance to bending, ALL frames flex and it is not dangerous in the least.

Originally posted by RacerX
ALL frames flex and it is not dangerous in the least.
Uhm, RacerX, I thought the purpose of this thread was
for us to convince these guys its dangerous so we can
get a DeRosa Planet for $50 ?

Marty