We check out the new Rotor Flow aero cranks
The Flow is Rotor’s premier aero crankset, designed in conjunction with Robbie Ketchell, aerodynamics guru and Director of Sport Science at pro road outfit Garmin-Sharp. Rotor claims a time saving of 26.4 seconds over 180km when averaging 200w, which equates to just shy of six seconds over 40km. It’s a small saving considering the cost, but could prove useful in a race.
With low drag at the forefront of the design process, Rotor’s engineers used computational fluid dynamics (CFD) to simulate wind tunnel tests and come up with the most aerodynamic shape possible. This is most evident on the edges of the crankarms, which are arrowhead-shaped rather than flat or rounded.
The arms themselves are made from aluminium, with internal holes drilled in to save weight without affecting stiffness. An oversize 30mm axle adds to the solid feel; we used Rotor’s BSA30 bottom bracket to fit it in a standard threaded BB shell.
The solid, disk-like spider (available in standard 130 bolt circle diameter or compact 110 BCD) incorporates Rotor’s new Micro Adjust System. If you choose to use the company’s elliptical Q-Rings, this lets you fine-tune their position to achieve your maximum power output.
Looking at the Flow, it’s obvious that it has a smaller frontal area than other cranksets. But bear in mind that the price doesn’t include chainrings, and the overall cost once you’ve added your rings of choice could end up greater than other top-end chainsets.