Why Alu? I became fascinated with pushing the boundaries of aluminium for frame construction during my time designing for Kinesis UK. By using clever tube manipulation, advanced tubing and sensible design, a modern aluminium frame can rival composite on weight and ride feedback and quality. Modern aluminium frames draw on many of the design influences learnt from composite frames, such as oversized BB’s, taper head tubes and switchable internal routing. Teamed with a properly designed carbon-monocoque fork, the contemporary Aluminium frame is a formidable piece of kit.
Aluminium also has the advantage of being relatively economical to produce and easier to manipulate and form than other materials like steel and Ti. This means that the finished product, although still high performance, does not have to be high price. In my opinion it makes way more sense to own a highly developed Alu frame, rather than a cloned composite frame of the same price.
Like the top tube on it’s steel cousin, the top tube used for the Definition has a pronounced ovalised section. The wide profile gives great lateral stability, especially when stomping hills out of the saddle and it mates perfectly with the large head tube giving increased weld area for strength and durability. The tube flows beautifully into the seat stays as it passes the seat tube, not only pleasing to the eye but excellent structurally at this crucial area.
A full 48mmØ allows wall thickness to be pared down without loss of overall strength, torsional stability and ride quality. The oversize tube also gives a greatly increased weld area at the base of the taper head tube and at the bottom-bracket shell, and allows us to pass the control cables, hose and wires cleanly through.