Following on from its acquisition in 2007 of aero wheel specialists Zipp and subsequent release of Zipp-inspired deep carbon rim aero wheels, components manufacturer SRAM has, for 2010, come up with a three-model range of road wheels with aluminium rims of more conventional depth and minimalist 18 front/20 rear spoke counts.
The new range starts with the S27 Al Comp, which has cartridge bearing hubs, bladed Sapim CX spokes with brass nipples and the same all-radial front/radial drive side, tangent non-drive side rear spoke arrangement as the others but employs a 27mm deep rim with traditional cross section to create an entry-level wheel designed for fast training with a claimed weight – minus rim tape and skewers – of 1620g.
A semi-aero aluminium rim with “hybrid-toroidal” cross section is used for both the S30 Al Sprint and S30 Al Race wheels. This rim has a squashed version of the bulging cross-section seen on Zipp’s aero wheel rims; the bulge behind the braking track catches and re-attaches airflow that has broken away from the tyre and rim profile behind the tyre. This is said to improve air penetration at various yaw angles and thereby reduce aerodynamic drag.
Of the two wheel sets, the top-end S30 Al Race has bladed CX-Ray spokes with internal aluminium nipples and a hard “Black Diamond” titanium carbide finish that matches SRAM’s RED groupset, while the mid-range S30 Al Sprint has Sapim CX-Sprint spokes with internal aluminium nipples, a black mirror finish and a claimed weight of 1495g.
All three wheelsets have SRAM/Shimano compatible freehub bodies. Availability mid-2010.