This article first appeared on Bikeradar
Trek's next-generation Madone isn't set for official release for another two weeks but RadioShack-Nissan riders were racing on it at the Critérium du Dauphiné. This new version borrows several key design features from the company's Speed Concept time trial machine, giving the Wisconsin company the aero road bike they’ve been missing for the past few years.
Much like Scott's Foil, the new Madone doesn't actually look all that slippery with its broad tubes and relatively shallow profiles. However, markings on the frame – not to mention strategically applied paint – point to a Kamm tail design with truncated airfoils that are said to mimic the aerodynamic benefits of a much deeper profile without violating UCI technical guidelines or sacrificing chassis weight and ride quality.
Trek have taken the radical step of moving the rear brake down below the chain stays. Just as significant, Trek has wholly adopted Shimano's new direct-mount interface, which does away with the traditional center mounting holes in the frame and fork and replaces them with twin posts on which the newly symmetrical calipers attach directly. In some ways, this is similar to the U-brake posts of old mountain bikes.
In theory, this design could save a few grams by virtue of the omitted caliper parts but the bigger expected benefit is a more direct lever feel and increased power thanks to reduced flex. In addition to locating the caliper arms closer to the base of the frame, the pivots themselves look to be adjustable for play for truly slop-free action.
Another side benefit is the more slender seat stay design. In contrast to the current version's wishbone layout, the new Madone stays are fully separate from dropout to seat tube and there's no bridge whatsoever. These changes could yield a more comfortable ride.
Given the more complicated position, the rear brake is built with a more convoluted X-shaped scissor linkage and the housing runs through the down tube. There's no barrel adjuster built into this end but seeing as how no rider would be able to safely use it anyway Trek has wisely opted to integrated one into the stop on the head tube.
Speaking of routing, Trek maintains fully internal paths throughout but with new easy-to-access ports on the head tube that provide a clea look with optional flush-fit plugs when using electronic transmissions.
Carryover features from the current Madone include a tapered 'e2' head tube, Trek's no-cut seatmast design, a pocket in the chain stay for a Bontrager Duotrap wireless speed and cadence sensor, and a 90mm-wide bottom bracket shell with correspondingly broad down tube and chain stay spacing and direct press-fit bearings.