frame material

Winter Larry sent me this email:

Hi Jim, Thought of something to discuss on your blog....best frame material...I like all but carbon as it seems fragile!

We had a bit of back-and-forth about that. My response to him included this:

Frame material is like a religion; people have opinions that are not always based in facts, and can't be shaken by facts.

Larry has aluminum & titanium frames, and frequently points out at ride starts if there are a number of titanium frames among the riders (in a later email, he said about aluminum frames, "I am one of the few who likes the old ones that most regarded as harsh..." * ). He also mentioned that he thought club members had had particular difficulty with stress cracks in one particular brand. 

When I made up the Yellow Maserati, my Ti-framed bike, I had a few criteria for the parts:

1. I wanted to bring the price in where I would not excite the ire of The Excellent Wife (TEW);
2. Except for "wear" parts, I wanted to build it once, and not be continually upgrading. I thought of wear parts as tires, chains, cassettes, and chainrings, but I've since learned that rear derailleurs, wheel rims, and saddles might be thought of that way. As for bar tape, that's not even a wear part; I change the bar tape only slightly less often than I change my clothes.
3. I wanted it to ride well.
4. I wanted to build it myself.

At the time I built the bike, a few years ago, carbon fiber had a reputation for "catastrophic failure". I replaced a carbon fork on my old bike (the one before the Yellow Maserati) after a drop when the epoxy matrix around the carbon seemed to be delaminating (although I admit I didn't know what I was looking for, and I might have done so too quickly). I found an inexpensive titanium frame, and put on a steel fork (it didn't hurt that the steel fork was far less expensive than a similar carbon one). I love my bike; it suits me well, it's fitted to me, and, for a guy who's pushin' 60, I get it goin' pretty quickly. If the fork died, I'd probably put on another steel one, because I don't see any additional benefits I'd get from a carbon fork that would be worth the cost.

I did research today about lifespan of carbon fiber bike materials, and the most heated discussions online appear to be anywhere from four to ten years old. Manufacturers offer lifetime warranties on frames and forks, which suggests that they're not concerned with lifespan. I did some research on stress cracks, and, especially in earlier incarnations of carbon fiber, it appears that cracks were common in clearcoat, which may or may not have extended to the epoxy matrix of the carbon fiber beneath, but these articles were also several years old.

I don't know if carbon fiber has a lifespan. My issues with carbon are these: first, I like the retro look of old steel. Carbon bikes appear to embrace novelty for its own sake. But that's solely a personal preference.

Secondly, carbon is expensive, although (as occurs with most technologies) price is coming down. (As I so frequently say, in matters bicyclistic, if there's a cheap way to do it, I probably know it.)

Third, while the structural integrity of a carbon frame may not be a problem, the integrity of the add-ons is suspect, in more cases than carbon enthusiasts might like to admit. I have seen broken, useless cable stops on carbon frames, and the rivnuts that hold the bottle cages work loose much more often on carbon than on metal frames. These problems may not affect the ride, but they do affect the usage of the bike. Without cable stops, indexed-cabled shifting systems won't work (although perhaps this is a plot to get us all to adopt electronic shifting). And I'd rather carry my water on my bike than on my back.

*I'll tell you what, Larry. If you want to reduce the harshness of that aluminum frame, ride wider tires. Even the tightest frame can almost always fit 25mm tires (instead of the 23mm, or even 19mm tires that many of us use), and they will do far more to soften the ride than any change in frame material.