Here's a little treat for all you cost-no-object tricknology fetishists out there. These carbon/aluminium beauties weigh just 70g each, compared to the likes of XTR rotors, which come in at 125g each. Bolts will add another 10g, less if you splash out on titanium models.
Oh, and while we're in the mood for obsessing about weights, aluminium rotors from the likes of Specialist Parts and Stan's No Tubes weigh 55g to 60g and cost £57 and £70 respectively.
But the lack of weight isn't the only issue here. No matter how carefully you treat aluminium rotors, they'll be nowhere near as tough as these beautifully made offerings. The carbon spiders hold the super-tough titanium rotors on floating ceramic bushes. The floating aspect means they won't rub if your fork and/or frame are flexy, lightweight offerings.
You're vaguely aware that they rattle a bit (well, it's more of a tinkle, really) as they float but you soon forget about it. They're available in 140 or 160mm sizes and you need to use SwissStop brake pads, but they're some of the best on the market so that's not a problem. The rotors work as well as any number of top-end discs, no better, and they look superb. The only problem is the price (349 euros or £249 approx) .