I've been away from the sport for a number of years and noticed a real change in the materials used to build frames. At the time I was racing, just about everything was steel and the only aluminum was the Vitus bikes, with aluminum tubes and lugged joints. Now it seems almost everything is aluminum, carbon, or aluminum/carbon mix.

Anyway, I'm looking to start riding again and an aluminum frame is most in my budget. I have a question regarding the aluminum frames with carbon seatstays or rear triangle. It would appear that the carbon serves 2 purposes, to lighten the weight and to soften the ride. Is this correct or is there more?

For the vibration dampening affect, is the carbon rear more beneficial to heavier riders, lighter riders, or both? I'm about 5'7" 145lbs. and was wondering if the extra $$$ to buy a frame with a carbon seatstays/chainstays will be worth it.

When it comes to adding CF stays to aluminum frames, there is some evidence that they actually add weight as opposed to lessening it. In terms of ride, there are those that say it improves it and those who don't. I find myself in the latter camp, owning two bikes both built with V107 tubes, one with CF and one without. No difference for me, whatsoever. Many feel that the primary advantage to CF stays/rear is that it makes the bike look cool and it's easier for the builder to build.

The only unarguable point that applies to your questions is that you'll get a lot of conflicting opinions.

When it comes to adding CF stays to aluminum frames, there is some evidence that they actually add weight as opposed to lessening it. In terms of ride, there are those that say it improves it and those who don't. I find myself in the latter camp, owning two bikes both built with V107 tubes, one with CF and one without. No difference for me, whatsoever. Many feel that the primary advantage to CF stays/rear is that it makes the bike look cool and it's easier for the builder to build.

The only unarguable point that applies to your questions is that you'll get a lot of conflicting opinions.

Terry b's got it. It all depends on the construction technique and the design (shaping, layering, etc.) of the different parts. To give you an idea, I've compared a Cyfac pure-aluminum Proxidium frame (very briefly), its brother the alu/carbon Proxidium Carbon, and its cousin the alu/carbon Nerv. The aluminum and carbon parts of the latter two are shaped differently.

Going from the Prox to the ProxCarbon actually feels more stiff and with a little more weight, even though the aluminum parts are identical. Going from the Prox to the Nerv gives more comfort, due to the shaping of the alu tubes and carbon parts. The Nerv is also lighter, but it is more high-end anyway. In most cases, the carbon parts tend to be able to dampen high-frequency vibrations, but this is not true in every case.

If you were riding road bikes before, you may recall the time when there were many aluminum and steel forks, and that carbon forks were just coming out into the market. Most aluminum forks were flexy, and the carbon ones tended to be more stiff. So it all depends on how you use the different materials.

There are many different Al and carbons so its hard to say. In my case I have a XLR8R front triangle and carbon muscle stays. I like the looks of this combo, carbon rear and carbon fork. The bike rides and feels great so thats all I care about.

Get what will motivate you to ride more and train harder.