Cannondale SystemSix Carbon Ultegra review

Cannondale claims that its latest SystemSix is the “fastest bike in the world”, and top line wind-tunnel testing figures certainly add some weight to that with the Cannondale SystemSix generating drag of 203 watts. That’s lower than the Cervélo S5 (206W), Ridley Noah Fast (213W) and Trek Madone (212W).

If the numbers add up, it’s partly down to the chassis, which is based on a Kammtail design.

In cycling circles, Kammtail is a teardrop shape greater than the UCI’s stringent 3.2:1 rule on design parameters. To satisfy the UCI, the end’s then chopped off and, by the miracle of physics, airflow acts like the ‘chop’ had never happened. The virtual tail keeps airflow smoother for longer thus reducing drag.

In fact, aero features are numerous: the front fork is asymmetric to balance out airflow from the disc and non-disc side; the seatpost is deep and aero shaped and the low-slung stays shelter behind the deep seat tube to avoid disrupting the air.

The science adds up, it looks stunning but, of course, it needs backing up with the ride.

Cannondale SystemSix Carbon Ultegra kit

The SystemSix is dressed in Shimano Ultegra and a racy but well-spread 52/36, 11-30 gear ratio. The only deviation from the Ultegra group is a step down to RT81 steel rotors over Ice Tech. These offer decent braking but at the expense of screeching when hot and in the wet.

Elsewhere, the Vision Metron 4D MAS flat aerobar and Vision Trimax QS stem are impressive. The bar’s super-deep top section leans forwards into a drop based on FSA’s compact drop shape, which is one of the best around, while the Trimax stem features an aero cover in place of a traditional four-bolt faceplate for drag reduction.

They’re tightly built but dish out a comfy ride. The SC 55s retail for £1,055, so it’s impressive to see them on a bike at this price.

Cannondale SystemSix Carbon Ultegra ride impressions

The SystemSix doesn’t ride like aero bikes of old. That’s heavily down to the geometry: a 580mm stack (on my 58cm test bike), reach of 398mm and a wheelbase that’s just under a metre; the frame features a 73-degree head angle and a seat angle of 73.5 degrees. It all makes for the usual aero rapidity but also an unexpected agility.

On climbs, which are often an aero bike’s achilles heel, the SystemSix impresses. Lightness helps because, despite 55mm-deep aero wheels, it’s just 8.43kg, which is lower than many of its rivals.

The stiff chassis is responsive, too, and these two variables unite for a bike that revels in out-of-the-saddle ascents.

As a bonus, once you’ve crested the climb, you can then take advantage of the bike’s premium handling and aerodynamics.

The SystemSix also scores well on comfort. Yes, it’s firm and stiff but it’s never rattlingly uncomfortable, even on broken surfaces – and that’s despite, on first look, the odd choice of 23c tyres. However, there’s a range rationale behind that selection…

The top-end SystemSix rolls atop ultra-aero 64mm-deep KNOT 64 wheels. Their super-wide 32mm rims have a wider internal width than the Visions, so the 23c versions on the premium SystemSix measure closer to 26mm.

Launch Gallery

On this model, however, the smoothing of air’s diluted because of the Vision SC55’s slimmer 19mm internal width. Plus, while the graphene-infused Vittoria Rubino tyres grip superbly in adverse conditions and roll well, the narrower profile demands higher tyre pressures to avoid pinch-punctures, which dilutes comfort.

A broader tyre would help both and be more befitting of such a fantastic bike.

Cannondale SystemSix Carbon Ultegra geometry

• Sizes (* tested): 47, 51, 54, 56, 58*, 60, 62cm
  
• Seat angle: 73.5 degrees
• Head angle: 73 degrees
• Chainstay: 40.5cm
• Seat tube: 55.3cm
• Top tube: 57.6cm
• Head tube: 17.2cm
• Fork offset: 4.5cm
• Trail: 5.7cm
• Bottom bracket drop: 6.9cm
• Bottom bracket height: 27.1cm
• Wheelbase: 1,000mm
• Stack: 58cm
• Reach: 39.8cm