Road Cycling - Question on durability of carbon/ aluminum bikes

Hello all, I tried to search but couldn't get an answer to satisfy me. :)

I am looking to buy a new bike in the next 2-6 months. I do mostly tri's (4-6 per year), and am looking to start doing maybe 2-4 crits/road races next year. I know I want to stick with a traditional geometry frame, i.e. no tri specific bikes. Right now, I am riding an OCR 3 with clip on aero bars. Serves it's purpose but I didn't think I would be getting this serious into racing when I bought it last year.

So my question is about the durability of bikes with carbon forks and rears. I am 6'1" and 185-190. I have been looking at bikes such as Bianchi Veloce, Fui Roubaix, Fuji Team, Trek 2200 and 2300 to name a few. I really like the steel or aluminum/carbon mix. I ride my normal races during the year and put about 100-200 miles a week on, which will be increasing when work slows down. This bike will be a keeper if at all possible. I am young, just married and will be doing the kids thing within the next 1-3 years. I need someting that will last me at least 5-8 years for me to be comfortable spending 1200-2000 right now. I know if I bust a carbon fork, I can find a semi-inexpensive one. But what if one of the seat stays breaks? How would that be replaced and would it be half the cost of a new bike? Thanks for any inpt on this. Any suggestions on other bikes would be greatly appreciated too.

You'll be fine. Carbon Fiber is not a "weak" material, properly designed it is MUCH stronger than any metal material. Basically if you get into a situation that breaks a piece of carbon fiber (especially on the stays or fork) you'll have broken/twisted a metal frame to the point that it would be unrepairable 99.99% of the time.

Andrew

As Ajay213 suggests, a carbon fibre frame would be the right choice for triathelon competition. However, be mindful that the strength of carbon fibre is not a universal property of the material. Carbon fibre frames have some serious drawbacks that any owner should be aware of. They generally cannot be repaired. Their much bragged about strength is greatest in a zero degree plane with the frame tube. As the angle of stress moves away from zero, the strength of carbon fibre and it's ability to withstand shock or other stress drops well below that of other popular fgrame materials. But, it is still a great choice for a frame that is to be used competitively. Especially if you are very careful and don't allow the bike to get tossed around, fall over, or otherwise recieve any serious impact stress to the frame tubes.

They generally cannot be repaired.

Very much true, they generally can't be repaired. But the repairability of steel/Al is often much bragged about, but it's not as simple as people make it out to be. Bend/dent/break a tube and you don't just cut the old one out and slap a new one in there. The costs associated with doing that becomes quite an issue (remember you are paying for more than just a tube repair, you are paying to safely remove the old, safely/properly install a new one AND a repaint), basically unless there is something "special" about the frame it is generally better to just replace it than attempt to repair it.



As the angle of stress moves away from zero, the strength of carbon fibre and it's ability to withstand shock or other stress drops well below that of other popular fgrame materials.

Carbon fiber is 5 times as strong as steel and Al when it comes to strength/weight and has with tensile strength carbon and steel are almost dead even (Carbon is a little higher, but not by any appreciable amount), however the steel piece is 6 times heavier.

This is where people always associate "weakness" and carbon fiber though, is it's resiliency, the ability to "stretch" (this could be in any direction) before breaking. In which case yes, a piece of carbon fiber can only "stretch" a very small amount before it breaks. The problem is that the force needed to "stretch" and break carbon fiber will permanantly bend a steel/Al tube.

Andrew

Thank you for the replies. Like I said, I just wanted to make sure I wasn't going to break it in undue time.

Ummm...to me, the most obvious response to your question was to point out that long-term warranty supplied with most bike frames that are going to be offered in Al/C. I think many or most have a lifetime warranty. :beer:

Ummm...to me, the most obvious response to your question was to point out that long-term warranty supplied with most bike frames that are going to be offered in Al/C. I think many or most have a lifetime warranty. :beer:

Good point. :D