Rotor cranks – and the brand's innovative non-round chainrings – are now a common site on road bikes, and they’re becoming increasingly popular off-road too.
It’s not just the Q-Rings that are unique to Rotor – the straight crankarms are triple-drilled down the centre and machined on the outside faces. Even though the 2 series’ crank arms use lower-spec 7075 alloy as opposed to the rarer 7075 mix of the 42g-lighter Rex 1 cranks, the whole setup is still an impressively low 600g.
The cranks are stiff when you bounce on them or brace yourself against the bars and they’re supported on a 30mm UBB alloy axle. Rotor’s UBB system was one of the first to allow 30mm axle use across all the popular frame types too, including those normally restricted to 24mm shafts.
The reversible crank cap makes fitting and removal simple as well, so the only thing to be careful of is correct sideways spacing, as the straight arms can bring the tips very close to the chainstays on some bikes.
The arms mount onto a solid spider with multiple mount points for the unique off-centre Q-Rings, which are designed to smooth out pedalling and increase power. Rotor even offers a 30-day money back guarantee if you’re not convinced, or you can opt for a SRAM-ring-compatible spider from the start.
This article was originally published in What Mountain Bike magazine.