Kestrel RT700

Kestrel is a consortium of composite engineers who, beginning in 1987, elected to abandon the cloak-and-dagger world of military advanced composite engineering and circle their wagons around the cycling industry. Since that point, Kestrel has either shared or exclusively introduced every innovation related to advanced carbon fiber frame and component construction. If any one frame reflected the sum of Kestrel’s know-how and performance ethos, it would be the RT700. The 700 borrows much of the aerodynamics from the Talon and blends the conventional sprinting and climbing potential of its ‘Evoke’ line to produce a wicked-looking frameset that is designed to be just as happy on a double century epic as it would be on the starting line of a road race or sprint-length triathlon.

Kestrel’s modular monocoque carbon RT700 (700k carbon) frame is designed in two halves-both constructed using high-modulus 800-series carbon material and expensive high-pressure internal bladder-and then bonded together using high strength, two-component adhesives. The engineering comes out of Kestrel in Santa Cruz, California, and actual construction takes place in three factories. Forks, seatposts and handlebars come from Taiwan, and the frames from China. (In case you balked at that, rest easily knowing that it was Kestrel who successfully established the carbon fiber manufacturing techniques and quality control regimens for cycling products in the industry’s key Asian factories). The Santa Cruz workshop does final checks and assembly.

The Kestrel RT700 is a beautiful and sleek bike, it’s just not a comfortable, all day machine.
The R700’s frame is unlike any we have seen. Its slightly curving frame members are duplicated by other marques, but closer inspection reveals there may be a generational gap between the 700 and the others. At the head tube junction, the top and downtube wrap around the head tube and encompass the headset bearing races-effectively reinforcing the areas where stress inputs into the frame from the fork. Each tube varies in shape and thickness along its length, and internally, the walls are ever-changing due to Kestrel’s multi layer and orientation carbon layup procedure. Frame members that directly strike the wind are mildly aero profiled-but not to the extent that the 700 frame incurs a weight penalty or begins to handle like an overly rigid full-aero time trial design.

Cables and housing are routed internally, and design consideration has been given to make it easy to re-cable the frame without resorting to fish hook and flashlights. The 1-1/8 inch headset is integrated into the frame and another nice touch is that those who wish for a round seatpost, instead of the supplied Kestrel carbon aero-profile item, can buy an adapter and make the painless switch to a 27.2-millimeter conventional seatpost. RT700 frames are available in five sizes (48, 51, 53, 55 and 57 centimeters) and weigh 1.1 kilos (55cm frame).

Our RT700 came outfitted with a Shimano Dura Ace group, Mavic Ksyrium ES wheels, Hutchinson Fusion 2 tires, and FSA SLK carbon cranks. The Kestrel Fluid Design aerodynamic seatpost weighs 245 grams, and the remainder of the office is decked out with an FSA forged alloy stem and Kestrel’s carbon EMS Pro handlebar. Kestrel offers three build kits for the RT700: SRAM Force, Shimano Dura-Ace and Shimano Ultegra. Our Dura-Ace model sells for $4899. The frameset (including Kestrel’s design-specific carbon fork) runs $2199.

Our 57-centimeter test bike featured a 73.5-degree head angle with a 73-degree seat angle, 26.7centimeter bottom bracket height and a 41centimeter chainstay and 81.2-centimeter standover height. In case you were wondering, our 57-centimeter ‘700 weighed 16.2 pounds.

A side view of the headtube on the RT700 displays the artwork of the constantly varying tube sections on the frame.
The RT700 gives back what you put into it. It sticks in the corners and its stable steering builds confidence on fast descents. There is little wasted energy on this stiff and solid-feeling frame, but it comes at a price. Kestrel remarks that a degree of comfort was a primary design consideration of the RT700. This important performance aspect, however, was not apparent. When riding over normal road chatter, we felt fatigue beginning to take its toll on our hands and lower backs after only a few hours on the bike. A powerful climber may appreciate the RT700’s flex-free power transfer, but its rigid ride erodes any benefits that its semi-aero frame could give a rider on the flatter sections of highway.

The Kestrel RT700 is a beautiful, well-constructed, finely detailed bicycle that elicits many comments on group rides. RBA’s test crew was not convinced, however, that the RT700 is a bike for spending long hours in the saddle. We tried switching saddles and changing positioning on the bike, but multiple test riders all came back with a similar response. The ?700 is stiff, responsive and it descends well, but it is not a bike we would ride in a century or spend more than four hours on a training ride without looking into some comfort-enhancing component swaps.

Price: $4899 
Weight: 16.2 pounds