Interbike 2009: Carbon rising

When it comes to cycling, carbon, which used to be called carbon fiber, which was actually a technical implementation of plastic, is becoming the new metal.

From the early 1990s days of carbon road frames that pioneering manufacturers like Watsonville, CA-based Kestrel and big-name companies such as Look and Trek built, carbon has made inroads into mountain biking as well (Kestrel’s seminal frames included). But frames are almost incidental to carbon innovation today.

At Interbike 2009, carbon bikes still are turning heads (the latest being Santa Cruz’s full-suspension 29-incher, the Tallboy). But carbon accessories and parts are showing up all over as well. And like frames, they’re being touted as stronger than aluminum, while also just as light and durable.

So you’ve got carbon handlebars, carbon seatposts, carbon rockers, carbon cranksets and even forks (lowers in mtb suspension forks). The least expected stunner: A carbon “chain,” actually a belt drive, that supposedly will outlast and outperform its veteran steel counterpart.

Although widely reviewed by test riders on a spot-ride basis, the Gates belt drive jury is still out, simply because so few real-life installations yet exist. The drive cannot be used with conventional derailleurs and is best suited to single-speed setups or an internal hub like the Rohloff. That said, it offers immense maintenance and performance advantages — as long as it lives up to its billing.

Similar claims are being made for other carbon parts, particularly handlebars. Once prone to chipping and breakage, bars today come with strength specs that surpass metal while soaking up hits better and transferring less shock for a smoother ride.

Carbon posts, which early on were flexy and unreliable, have made strides as well, although slippage remains a problem. And hollow carbon cranksets are turning in gram counts that put the shame to aluminum.

But is all the carbon chatter for real, or just industry hype aimed at suckering bleeding-edge types and weight weenies? We went through all this before with the first wave of carbon, which relied on pattern weaves and epoxy, and saw frames shatter, components fail and performance diminish quickly over time.

I’ve had three carbon bikes. The first, a Trek Y-33 bike, was light and stiff and compliant (it soaked up hits well). Its single-pivot design was not the greatest and it sure was noisy (the slightest sound reverberated through the hollow body) but the bike stayed in good shape as long as I had it (about a year before it was stolen). I got a Giant carbon hardtail in 2002 and loved it. It was by far the least harsh hardtail ride I’ve ever had. But the bottom bracket shell separated from the frame after about 9 months, and Giant, which had given up making the frame, replaced it with an aluminum model.

Today I have an Ibis Mojo for high-country XC epics, tipping the scales at 25.2 lbs. It seems tougher and sturdier than previous carbon, and I’ve had no issues in two years of riding. I’ve also ridden the new carbon Blur, which feels downright bulletproof. One thing about the Blur is how the one-piece molding transfers load so evenly, you don’t feel like you’re hammering the bottom bracket. The whole bike seems to soak up hard pedal action.

All that said, carbon is in many ways still too evolutionary to draw hard-and-fast conclusions. Carbon still can shatter, as evinced by Jeremy Honorez’s encounter with a traffic bollard. One doubts aluminum or steel would have survived such an impact either, but let’s remember we’re not talking infallibility here.

A lot of the carbon hype has to do as well with looks. Carbon molding, combined with its innate strength, can add some sexy curves and design innovations to a fork and frame. The press release usually banners the performance advantage, but let’s face it, a cherry design sells. And carbon is offering more design variability than aluminum or steel.

Manufacturers also seem confident about boosting carbon’s warranty claims, as Gary Fisher recently tweeted:

“I get asked ” is there a weight limit on your carbon MTBs?” No and they all have a lifetime Garantiee”

Fisher isn’t alone. Santa Cruz has replaced its aluminum Blur XC line with carbon Blurs (not everyone is pleased), and says its longer-travel Blurs will take any fork without risk of frame breakage. Other manufacturers, including Ibis, are making similar claims. Weight claims are getting downright feathery, with 22-pound builds not uncommon.

Carbon still does not seem ready for burly duty. No one yet is offering cranks for freeride or downhill action. Carbon frames are rare in those arenas as well, although they may be coming. Carbon forks, pedals and wheels also do not yet seem ready for the Big Hit crowd. Innovative Pivot went with a carbon rocker for its long-travel trail bike, the Firebird, but has since begun replacing the rockers with aluminum. The issue supposedly is to permit a coil shock, but you have to wonder whether carbon was holding up under the jumps and drops.

(Aside: I asked a recent mountain-biking acquaintance who works on parts specification for Boeing whether carbon was making any inroads into commercial airline production. He kinda laughed.)

Still, carbon’s future seems bright. While aluminum and steel are pretty much set in their ways and maxed out on specifications, carbon technology seems to improve almost annually. And let’s face it, the stuff is basically still plastic, which means costs should keep coming down with widespread adoption.

For now, carbon is cycling’s miracle drug. It’ll be fascinating to watch it evolve in the marketplace.

Links Links Links

Gates belt drive

Blur LT

MTBR.com at Interbike: Carbon, carbon, carbon!