Taiwanese company Aerozine first brought its cranks to market back in 2005, designed by engineers who used to work for one of the big players out there in crank world. The shiny polished X13 features an integrated two-piece set-up similar to the design Shimano uses with a splined bottom bracket spindle and pinch bolt to secure the left-hand arm.
Talking of the forged aluminium 7075 T6 arms, they might look chunky but they're actually quite aero with plenty of the material being machined out from the rear to help keep weight down; this means there's a pretty good strength-to-weight ratio going on. In use, this is noticeable and things are kept pretty stiff when you really put the hammer down.
The outer finish is top notch while a little less attention to detail has been paid to the rear of the arms, though it's by no means rough. The 172.5mm arms hit the scales at 732g while the BB adds an extra 90g. This means the X13 is really up there battling with the top-end chainsets on the market. Fitting is easy, and the BB slots in no problem but you will need a specific tool, as there isn't one in the box. The bearings run smooth and we had no problems during our test but only time will tell.
The 130mm configuration runs with the usual 53/39t aluminium chainrings but Aerozine does make a compact version too. If that wasn't enough choice, you can also go for black arms, although we don't think they look as good because they still run polished silver rings.