They’re hookless rims (seriously – why did we ever use hooks in the first place? They’re so passé). And they have new “double time” hub and pawl geometry. So lots of pawl engagement – there are 4 pawls, and 26 teeth in the ratchet ring – but only two pawls engage at a time. So 52 effective engagement points for a nice smooth buzz.
In their lightest configuration (you can tweak axles and XD or regular freehub), a pair of 27.5in wheels weighs a claimed 1390g; the 29in option weighs a claimed 1430g.
The cheapest option will set you back £1512 (that’s £722 for the front wheel, and £790 for the rear). Add on £30 to the front hub price if you want the Predictive front hub for Rockshox’s new RS-1 fork.
More details from SRAM