Standard SLX M660 cranksets have three chainrings but you can also get this chunky double-plus-bashguard unit with 170 or 175mm arms. It's intended for use with a nine-speed cassette but we ran a narrow 10-speed chain on it without any problems. For all intents and purposes it’s a much more durable version of the standard SLX crankset.
The wide section hollow crank arms are very stiff and the bare outer surface stays scuff-free for far longer than black cranks. A burly steel axle and steel pedal inserts hint at the cranks’ intended hard hitting abilities, as does the fat polycarbonate bash guard. But the weight is still reasonable enough for cranks like this to appeal to ‘normal’ trail riders.
The 36/22-tooth chainring pairing is just right for go-anywhere, do-anything use and the steel inner ring will probably last for as long as your bike. At the price this is probably the best made harder hitting crankset on the market. If you want guaranteed 10-speed compatibility you'll have to opt for the latest M660-10 triple or wait for the new M675 double, due to be released in June.