I am currently in the market for a new bike, (crashed and trashed my current one, waiting on the insurance to come through) and just like Bigfatbloke (comment #12) I really like the look of the Bianchi 928 bikes. Researching on the Web finds lots of discussions, some very emotive, but all seem inconclusive and short on hard facts. So what do I do?
I’ve always found it best to go as close to the source as possible for accurate information, so I contacted Bianchi. I had a very interesting and very informative conversation discussing the perceived advantages/disadvantages, longevity and durability of carbon and aluminium frames. I was very satisfied with the answers I received to my questions, and the depth of knowledge and willingness to discuss plusses and minuses by the guy on the other end of the phone.
In summary: carbon surpasses aluminium in every way – except on price. A cared for carbon frame, (and who is going to pay carbon prices and not take care of it?) will last indefinitely. Particularly with the demi-coque construction method used by Bianchi, (no carbon cycle frame can be truly called a monocoque as it is impossible to make it in one piece).
What will compromise the frame’s integrity - anything that inflicts sufficient damage to break through the protective outer layer and cut into the carbon fibres? How many fibres need to be cut before damage is critical – nobody knows? It’s a bit like a multi-stranded rope. Cut a strand and you may well be okay. Cut some more and it will eventually fail. When it actually fails will be determined by use, stresses and the performance of that particular rope.
Bianchi guarantee their frames for five years against the usual faulty material or workmanship.
As for the different failure modes, well that’s a separate issue, but I’m looking forward to riding a new 928 as soon and my collar bone heals.