Double Diamond
By all appearances, the frame of the Guerciotti is the standard Double Diamond that has dominated the industry for most of the last one hundred years. There are very few things in this world that can't be improved upon. But the Double Diamond, a technological advancement succeeding the Rover safety frame, circa 1885, is one of them. And for solid engineering reasons, too. The triangle is an inherently strong geometric shape, possessing a superior stability factor and bearing a remarkable strength-to-weight ratio of (>50:1).
Five triangles actually form the Double Diamond bike frame, connecting it to the rear wheel at one point, the pedal and sprocket apparatus at a second, the fork and thereby the front wheel at a third, while allowing for the weight of a rider to be supported at a fourth. The early High-Wheeler bicycle of the 1870's operated with a crank pedal attached directly to the front wheel, which was also the steering unit, requiring a great deal of dexterity to manipulate. Mounting and dismounting the contraption was plain awkward, if not, just down right hazardous. The Double Diamond design revolutionized the High-Wheeler by lowering the center of gravity and separating the propulsion functions from the steering functions via a chain driven rear wheel. An advancement that is not ever likely to be improved upon.
Modern improvements are mainly innovations. Bicycle components, and the materials they are made from, due to technological advances, have certainly evolved over the course of time, but the basic bicycle design remains the same. Most noticeably, there have been some radical material changes in the tubing of the frame. Originally made of steel, they are now constructed of aluminum, titanium, carbon fiber, and other high tech alloys. Among the very newest innovations is the Columbus Nivachrome tube, from the famed House of Mondonico.
Mondonico bikes were custom built, one at a time, from 1929 -1978 for only the most discriminate, demanding and appreciative of cyclists. Guiseppe Mondonico, long recognized as a true talent by the elite of the Milan cycling cognoscenti, handed down his vision, talent and skill to Antonio, his son, who partnered up with Paola Guerciotti from 1978 -1988 to produce the finest bikes the world had ever seen. The bike Bob acquired has a "screwed and glued" Mondonico aluminum frame. Unique to Mondonico, the joints of the frame are packed with glue and then screwed together with aluminum lugs. Such construction provides a little extra give --a bit of extra spring that helps it absorb shock. It’s a very lightweight and extraordinarily forgiving frame.
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