- The Cannondale RS, originally created for time trial, its fit adapts well to triathlon.
- The integrated stem is offered in different lengths but doesn't allow stack adjustment.
- Cables and housing thread into the integrated stem.
- The seat stays are full airfoil shapes.
- The fork extension covers the head tube.
- Kinks in the seat stays are intended to reduce drag and mute vibration.
- Extremely clean front profile.
- Cannondale's V brake doesn't kink the cable.
- The rear and front stoppers are both V-brakes.
- The V-brake arms are hidden behind the fork blades.
- Press Fit 30 bottom bracket.
- The downtube is also a narrow airfoil.
- The forward-set seatpost is a critical component for tri fit on this frame.
- Seat stays jut out from the seat tube.
- Horizontal dropouts.
- The connection between the seat tube and down tube is very tall, filling in a lot of the front triangle.
Originally a time trial bike, the Slice RS can be adapted to fit many tri positions.
First designed for time trialists, Cannondale’s Slice RS had some geometric obstacles to becoming a good triathlon bike, but Cannondale used the perfect components to overcome those shortcomings.
The Slice RS’s integrated fork and aerobar attachment system is its key feature. With the stem and fork as one piece, the Slice RS frame provides reach adjustment but no stack elevation. But it isn’t all bad news. Unlike many time trial bikes, this frame’s geometry is quite conservative, which should allow many triathletes to comfortably find their ideal position on this bike even without stack adjustment from the frame.
Frame stack and reach data
Size 50: Stack, 50; reach, 37.
Size 52: Stack, 51; reach, 38.
Size 54: Stack, 53; reach, 39.
Size 56: Stack, 55; reach, 40.
Size 58: Stack, 57; reach, 41.
For those who don’t spend their free time memorizing frame geometry charts, these dimensions are definitively conservative compared with many tri bikes. Even though the Slice RS offers limited frame fit adjustment, the bars are located in a realistic starting position for many triathletes. Vertical and horizontal adjustment from that point comes in two different ways.
For reach adjustment, Cannondale created stem pieces ranging in length by 4cm. Swap these parts to lengthen the front end.
The frame cannot lift the elbow pads, but Cannondale spec’d the ideal aerobar to overcome this problem. Vision’s Vector Carbon aerobars come on all the stock Slice RS builds, and they offer the ability to elevate the aerobars high above the basebar with shims. By offering the option to raise the bars dramatically, the Vector Carbon bar eliminates the frame’s front-end geometric shortcoming.
Slack seat tube angle is another relic of the Slice RS’ road heritage. The bike’s listed seat tube angle is just 75 degrees, much too slack for most triathletes. But again, the Slice RS overcomes this apparent fit limitation. Effective seat tube angle—the angle of a line drawn from the saddle clamp through the bottom bracket—is in fact steeper than the listed 75 degrees because that number is measured through the intersection of the seat post and top tube. But the seat post doesn’t follow that line, it comes straight up from the bike, creating a more forward saddle position than the geometry chart may indicate. The taller the higher the post comes out of the frame, the steeper the effective seat tube angle becomes.
The seat post also helps jack the saddle forward. Many road racers had the post in the rear-offset position, but it is also mountable in the forward orientation. Turning the post forward give another three centimeters of forward adjustment, putting the saddle pretty darn close to the sweet spot for triathlon positions.
V-brakes both front and rear stop the Slice RS. The front is mounted behind the fork, and the cable threads down through the headset bearings and turns to the side to actuate the caliper.
The rear V-brake is stowed behind the Press Fit 30 bottom bracket.
Brake and shift housing route into the frame at a 90-degree angle through the integrated stem.
Cannondale is building the Slice RS with three different component specs. The black and green paint job shown in the photos comes with SRAM Red and Zipp 808 tubulars. The mid-level option is spec’d with Vision wheels and Shimano Ultegra Di2. The most modest spec includes Shimano Ultegra mechanical components. For entry level bikes, Cannondale is keeping the original Slice.