Starting almost a year ago, I began designing the new Madone with Tyler Pilger by taking a close look at the frameset’s centerline geometry. Based on lots of rider feedback, field trips (road riding in Italy is great!), and years of experience riding and fitting riders on their bikes, we designed the frame geometry for a full range of sizes. I designed and oversaw the construction of several generations of aluminum prototypes in Trek’s Waterloo welding facility (Trek’s advanced laser mitering capabilities and flexible manufacturing staff make quick experimental frames easy), putting miles on each generation riding back-to-back comparisons with other bikes.

Finally, we settled on a range of sizes driven by the frame’s stack and reach dimensions. Frame stack and reach aren’t new; Dan Empfield has championed the concept for years. Seat position is pretty adjustable these days, but stems are a little less so. Because the rider touches the bike at “feet, seat and hands,” and since the new Madone’s sloping top tube makes the traditional way of measuring frame size less meaningful to riders, designing around frame stack and reach makes perfect sense.

In the end the new centerline geometry is essentially the same as the current, well-liked Madone’s, so if you ride a current Trek road bike you’ll find you fit the same on a new Madone of the same size. In fact most will find they fit better: For example, during the research phase, Tyler found most riders have plenty of head set spacers under the stem. As a result the new Madone comes in two Fits: "Pro Fit", with a standard head tube length to match the current Madone's hand height, and the new "Performance Fit", with a longer head tube (+30 mm) to permit a higher hand position (or the removal of some spacers).

Questions, comments, observations welcome!