This Dragonfly Pro, outfitted with Calfee’s proprietary internal Di2 solution and a full-carbon BarStem, was built for a cyclist in Texas. We hope to squeeze it into our booth at NAHBS. This bicycle, with it numerous innovations and striking finish, is a stirring example of our carbon craftsmanship.
Coeur d’Acier. As the name implies, this bike has a heart of steel, but a ride that sets the gold standard in performance. Awe inspiring drive-train acceleration while the Serotta Composites rear carbon stay and F3 fork provide vibration damping that is simply not found on other steel bikes. In fact most people who first ride the ‘CdA’ wonder if its titanium. Lightweight, versatile, fully rider tunable and 100% handcrafted in the USA. One ride and you’ll wish you had discovered the feel of Serotta steel sooner
Dragonfly; our lightest and most technically advanced frame.
The Dragonfly tube set was designed to build the lightest possible single and tandem bicycle frames without sacrificing stiffness, durability and ride quality. We use high modulus carbon fiber in all the tubes (55 msi) as well as the lug areas (42 msi). Previously, a frame built with all high modulus fiber would be too brittle. We incorporated Boron fiber into the three main tubes to add some toughness and compressive stiffness. Boron is an attractive reinforcement because the resulting composite combines superior tensile, compressive and flexural strengths, high modulus, and low density in one system. Combined with the super high tensile stiffness of the carbon, the result is a frame material with the highest stiffness-to-weight ratio on the market.
The use of boron fiber has come of age with its use in our high performance bicycle frames. Bicycle weights have dropped from 18 pounds back in the 1980s to 14 pounds or less in 2010. Much of this weight savings comes with the use of carbon fiber composites. As bicycle companies compete in the arms race to make even lighter, stiffer bikes, safety and durability are pushed to the limit. High modulus (55 Msi and greater) carbon fiber is being used to make stiff yet thin walled tubing. These tubes can be vulnerable to damage from a variety of real world sources. When slightly damaged from a pebble thrown up by a passing car, or an unfortunate event during a group ride or race, a thin walled tube can rapidly degrade to an unsafe condition. Our very popular Calfee Carbon Repair business is evidence of this common failure. Using boron filaments in the tube laminate mitigates this problem by significantly enhancing the tubes structural performance.
Calfee Dragonfly weighs only 2.1 pounds in a 54cm size, delivers power as well as any large diameter, thin wall frame, has superior vibration dampening, compressive and impact strength, and is protected by a 25 year warranty.
Dragonfly single and tandem lugs are pressure molded from high modulus fabric. With Dragonfly singles, lugs are made with carbon fabric formed around metal mandrels. These lugs and pre-mitered tubes are easily bonded together because they are so compatible. The carbon fibers are carefully oriented to put strength exactly where it’s needed while minimizing weight. Gussets are integrally formed with the fabrication of the joints, eliminating the inherent weakness of the tube and lug joint found in many other manufacturers designs. They are then meticulously carved to the optimum shape, taking into consideration the weight and intended use by the rider. They happen to look good because of their form-follows-function aesthetic.
The dropouts are also carved out to their optimal shape, saving 15 grams off the standard dropouts. This may not seem like much, but the way to build a 12 pound bike is to address every component and look for opportunities for weight savings, no matter how small. The trick is to do it without sacrificing strength and durability. As in nature, the Dragonfly is one of the most optimized and evolved structures to be found.