With the excellent 661 armour being used by vast amounts of riders, producing pads to face up to them is a tough job, but Fox have done it.
Each pad features a hard plastic shinguard and a separate hard cap for the knee, which sits on neoprene and biofoam pads. Below the knee there are two straps - one for the shin, one for the calf - and there's a neoprene gasket that you wear underneath the pad, which is attached to a heavy-duty nylon sleeve. This rolls down over the plastic kneecap, securing the pad better than a strap and providing better manoeuvrability.
Unless you have chicken legs, rolling the gasket up to your knee is
hard - the nylon feels like it's going to cut your circulation off - but as soon as you fold it down, it feels great. With no annoying strap above the knee, shorts sit well over the pad, and movement is superb. Needless to say, the protection's great, and there's little chance of the pads rotating.