These discs from Italian ﬁrm Braking have as much technology behind them as style. They're semi-ﬂoating, which means three of the six arms ‘ﬂoat’ on dowels, while the other three are rigid.
While the concept of ‘semi-ﬂoating’ may seem bizarre, it’s sound engineering. One-piece discs can distort under uneven heat loads, as the edges expand more than the cooler centres. Motorcycle makers solved this with separate central carriers and dowels, and mountain bikes have picked this up.
In practice, the S3 rotors don’t rattle and the chance of warping is reduced. Wavy edges and slotted faces clear the pads of gloop well, and response is crisp. They're not the lightest – the 185mm version is 163g – but they’re strong, work well and look pretty spectacular.
Braking cover the bases with 160/180/200mm and 165/185/203mm sizes, though if smaller discs suit your riding you’re unlikely to have heat problems. 180/185mm rotors cost £42/US$58.50, 200/203mm £47/$65.50 each. They come with six-bolt fittings but Center Lock adaptors are available for £12 each.
This article was originally published in What Mountain Bike magazine.