By Aaron Hersh
The TM01 features the only aerobar attachment system that combines structural adjustability and a streamlined shape. The nose extending off the front of the BMC is a modular stem assembled with three independent shim pieces. These pieces—one wedge, one short rectangle and one long rectangle—can be swapped or removed to change the bike’s fit. The final piece, which can be flipped to adjust fit, clamps a standard aerobar to the bike. The Profile Design T2+ BMC spec’ed on the bike is also highly adjustable and well-suited to more upright positions. Although this system cannot reach fits as tall as some aerobar attachment systems, it creates a remarkably sleek and thin structure that can be micro-adjusted to cover a multitude of positions in an exceptionally stiff package.
Although BMC only produces the TM01 in four sizes, it squeezes two distinctly different fit styles into those frame sizes. Three of the four sizes have fit coordinates that are slightly aggressive but not extraordinarily demanding. These three frames fit the same riding style. Combined with BMC’s stem system and the ability to use any aerobar, these frames can cover a broad range of fit coordinates without compromising ride quality. We tested the stem assembly in the tallest configuration and found it to be extremely stiff.
Many new tri bikes are being designed with geometry that allows the rider to sit in a position that is more upright than the three standard frame sizes allow. BMC acknowledges that some triathletes ride positions that are more upright than these three sizes are designed to reach, and it has a unique strategy to meet the needs of triathletes who cannot fit these bikes. Although the fourth size has identical features and shapes, its geometry is remarkably different from the other three. It might have the most upright frame geometry of any triathlon frame. It certainly opens this bike to athletes without the ability to ride low, but only for the select few who fit that fourth frame size. Currently the M-S is the only model offered with this geometry scheme.
The TM01 conforms to the regulations imposed by cycling’s governing body, the UCI. Its tube shapes aren’t outrageously deep, and the frame lacks integrated hydration or storage options. Despite restricting the design to the limits of another sport, the TM01 still boasts features triathletes can take advantage of. The tube shapes are all truncated airfoils, piggybacking on the Kamm tail shapes Trek brought to the world of cycling with the Speed Concept, with a raised segment at the leading edge. BMC asserts this helps reduce drag at wide yaw angles by preventing the passing air from fluttering away from the tube longer.
The integrated brakes—BMC’s own design—are essentially old-school mountain bike-style brakes. These V-brake style stoppers have two arms that pivot about an axle on each fork blade when the cable, strung along the top, pulls the arms against the rim. This structure creates a more powerful stopping feel than most integrated calipers, and the arms blend back into the bike when the rider is on the gas. It has no integrated storage features, except for the Shimano Dura-Ace Di2 battery.
The $4,999 version has the same highly integrated frame and fit adjustment range. Removing the Shimano Dura-Ace Di2 in favor of Ultegra and Zipp 808s for training wheels saves $8,000.