Thursday, September 5, 2019

1991 Carbonframes Onyx

Walking the expo at this past weekend’s Dirt Fest I couldn’t help but marvel at all the killer new bikes on display. As a fan of vintage bikes a vast majority of my experience with frame construction materials is mostly constrained to steel, aluminum and titanium. Carbon fiber, at least as we know it today was not widespread in the early days of mountain biking. Early attempts at composite bikes started coming on the scene with bikes like the 1987 Kestrel MX-Z and the 1988 Trimble Carbon Cross. Those bikes (which I will discuss in an upcoming web article) were considered a composite construction and unlike today’s true carbon fiber bikes had fiberglass and other materials incorporated into the carbon weave, which was often applied over a core, foam for the MX-Z and Douglas Fir (yes that’s a tree) for the prototype Trimble. These early attempts at building a composite mountain bike were novel and unique but in my opinion fell short of the label of carbon fiber bikes. While it’s hard to pin point with total certainty the first time all carbon construction was applied to mountain bikes this Carbonframes Onyx is certainly a strong contender for that title. 

Carbonframes was the first commercial venture of one Craig Calfee who went on to start Calfee Design who are well known for their organic looking carbon and bamboo bikes. While not his first carbon bike, that honor goes to the Sapphire road bike, the Onyx was his first and only attempt at building a carbon mountain bike (oddly enough Calfee makes off road cabon tandems these days). The Onyx is one of the more striking bikes I’ve ever seen, I think it would look equally at home in a modern art gallery or as prop designed by H.R. Giger for the set of Alien. 

The mix of organic curves of the frame and the way the carbon tubes are bonded together is contrasted by the sharp corners of the reinforcing gussets, making you think it was not design by an engineer but rather an artist. Turns out this isn’t far from the truth. Craig Calfee gained most of his practical knowledge of working with carbon fiber while working on Olympic caliber composite sculling boats and eventually sailing boats, while pursuing a sculpting degree at the New York City art college.  Craig combined those skills with his passion for cycling and started building all carbon bikes around 1988. The Onyx was a revolutionary bike at its time, and seeing it for the first time at the 1990 Interbike in Anaheim must have been breathtaking,  . Not only was the frame made of CF and weighing in at around 3.4lbs without a fork (at a time where most frames were over 4 lbs), but it also seamlessly incorporated elevated chainstay technology (I use that term loosely here) which was the new ‘it’ trend in the late 80s. The beauty of carbon fiber is that it is isotropic, and allows you to create structures that have physical characteristics that depend on the direction in which it is laid up. Craig understood this very well and set out to build a frame that is both rigid but has built in damping characteristics. I think if you compare it to the frames of the time you would agree with that to a point, also I imagine it helps being a spindly XC racer. However, with the benefit of 30 years of hindsight and for a guy who tops 200lbs the bike is not what you’d call confidence inspiring. As I write this I’ve not logged many miles on the Onyx, but the few I have combined feedback from others who have ridden it paints a slightly different opinion. The Onyx is a fine bike for an average XC jaunt on your local trails. It’s a fair climber and handles pretty well (courtesy of the short wheelbase). However it’s a different story when you point it downhill and toss in some obstacles, and things go a bit sideways quickly. Basically, if you watch your speed and keep things in check you’ll be fine, but my alarm bells were ringing anytime speed crept up into the double digits. So, while it wasn’t the best bike in the long run it was a true milestone in the development of today’s carbon bikes. As I gear up for the larger carbon story the thing that rings true for me about carbon is that it in terms of mountain bikes it was a technology without a real application that is until full suspension came along. So, bikes like the Onyx, Trimble, MX-Z and the famous Yeti C-26 were early explorations into a world of what could be, and what would eventually enable the radical machines many of us take for granted today.

The handmade, limited quantity production aspect of this bike comes through in the way the dropouts are integrated into the carbon stays.

1 comment:

  1. Thanks for posting this gorgeous frame and bike. A point of correction: carbon is not an "isotropic" material, quite the opposite, it has strong directional strength characteristics and is at best "quasi-isotropic" achieved through a layup schedule which specifies layers with different strand orientations. Isotropic materials are things like cast iron or diamonds, which have equal strength in all axes. Most metals used in bicycle manufacture are quasi-isotropic, varying with grain caused by their forming method. I might also add that carbon didn't really begin to reach it's full potential until non-tube shapes came into play, suspension or no. In fact, this has been the case for most bicycle frame materials (even steel:, which are now designed in highly irregular profiles to optimize material according stress loads. I appreciate your good work. Thanks for the posts!