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Trek has been on a hot streak of late, with the lightest production bike on the planet and, by many measures, the fastest aero road bike too. This current engineering hot streak began back in 2012 with the launch of the Domane—a bike designed for Fabian Cancellara and the cobblestones of Northern Europe—and it continues today with the latest version, the new Trek Domane SLR 9 Disc Pro Endurance. In fact, this is the bike, discs and all, that Trek-Segafredo will race in the Spring Classics. There will be no rim brake Domanes on the team’s race truck in 2018.
The Trek Domane’s signature technology is IsoSpeed, a decoupler that truly separates the stiffness needed for power transfer and handling from the compliance needed for comfort. It allows the set tube to flex independently of the rest of the frame. The new Domane SLR added the ability to customize that compliance with an easy-to-adjust slider at the seat tube. The bike can be a stiff racer, ideal for smooth pavement or a short criterium, or incredibly compliant for cobbles, dirt or long days over rough roads. And the new Domane SLR can be 14-percent more compliant than the original Domane.
But balance is what makes any bike truly special, and to find that balance Trek has introduced a front IsoSpeed decoupler. Hidden in what looks like a traditional front end is a decoupler that allows the steer tube to flex vertically, independent of the head tube. The addition of disc brakes has taken the Domane SLR’s category-leading versatility to yet a new level. While official tire clearance is listed at 32mm with room for fenders, we’ve easily fit 35mm tires. The Domane SLR Disc is a legitimate adventure bike and a threat at many gravel events.
For this test bike we opted for the more aggressive, race-ready geometry of the Pro Endurance version. It made our Domane SLR 9 Disc a bit lower and a bit longer, ready to compete on the limit over any surface with a simple tire change and a quick adjustment of the rear IsoSpeed decoupler. Our 60cm Domane Pro Endurance has a head tube 2cm lower than a typical 58cm Domane’s head tube. The bottom bracket is also lower, while the front center is longer, all adding to the bike’s stature as a true race bike, over challenging terrain.
The only way to get this Trek Domane SLR 9 Disc with Pro Endurance geometry—the same bike Trek-Segafredo’s classics specialists ride—is through Trek’s Project One program. Project One bikes offer an incredible level of customization, all created in Trek’s Waterloo, Wisconsin, factory. Three-dozen colors are available in multiple paint schemes, from the colors of the Trek-Segafredo team to Trek’s Real Fire design. Beyond custom paint, Project One allows you to spec the bike with your ideal build.
For this bike we opted for Aeolus 5 D3 TLR clinchers to get some aero help with a wide tubeless rim for great tire performance. Shimano Dura-Ace Di2 and Bontrager handled the rest of the build. Along with the wheels, Bontrager’s Pro IsoCore VR-C bars are a true standout on the build. Integrated pads reduce any high-frequency vibration that gets past the front-end IsoSpeed. In addition to the Pro Endurance geometry, custom paint and ideal spec, the Project One Domane SLR 9 Disc is made of 700 series OCLV carbon; the stock Domane SLR 9 tops out at 600 series OCLV carbon. From design to delivery, Project One bikes take between two to four weeks; our bike was ready to ride in three, tipping the scales at 7.7 kilograms (16.9 pounds) in 60cm with meaty 32mm Bontrager R3 tires.
All of the Domane SLR 9 Disc Pro Endurance features—IsoSpeed up front, adjustable IsoSpeed out back, disc brakes, high-volume-tire clearance, 700 series carbon, low and long geometry—make the bike more than just comfortable and quick. They make the Domane SLR the most versatile bike on and off the road. Stiff under power and lively at the pedals at just over 7 kilos, it is as at home in the hills as it is on the cobbles. While 35mm tires may be overwhelmed at Dirty Kanza, at events like Gravel Worlds in Nebraska or many West Coast races over fire roads, the Domane SLR disc would be a very potent weapon. Pounds less than many gravel bikes, it would excel on any hilly, rough course.
The IsoSpeed creates enormous comfort and confidence in the saddle and precise handling at the bars over the roughest surfaces, while remaining laterally stiff through the bottom bracket for big sprints and rock solid through the head tube for fast corners. IsoSpeed is no gimmick. It works.
Born for battle over professional cycling’s most challenging terrain, the Trek Domane reinvented what it means to be an endurance bike. The Trek engineers in Waterloo have once again raised the bar, creating what is the most versatile bike in the peloton, the Domane SLR 9 Disc with Pro Endurance geometry.
PRICE: $13,500 (as tested)
WEIGHT: 7.7 kg (16.9 lbs); 60cm (w/o pedals or cages)
BUILD: Shimano Dura-Ace Di2 9170, Bontrager Aeolus 5 D3 TLR carbon clinchers with Bontrager R3 tires. Bontrager IsoCore VR-C Bars with Pro-Black stem and Affinity Pro carbon-rail saddle.