SRAM says low profile hubs reduce drag and help to focus support for the entire wheel around the oversized axles.
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Aluminum wheelsets see further collaboration with Zipp technology
SRAM has marked the start of its sophomore year as a wheel manufacturer with a range of three new aluminum wheelsets. The S27 AL Comp, S30 AL Sprint and S30 AL Race see the company target the low-to-mid price categories as SRAM reaps further benefit from its relationship with Zipp.
SRAM leapt into the crowded wheel marketplace last season with a race of mid-to-deep dish, alloy rimmed carbon wheels based closely on Zipp's similarly profiled models. The new S series still employ technologies developed under the Zipp banner but presents arguably more practical options than their deeper-dished stablemates.
While in raw numbers each wheelset is differentiated by numbers of weight and cost, all three employ alloy rims paired with newly designed hubs via Sapim stainless steel spokes in an 18-front, 20-rear distribution. With SRAM targeting a compromise between stiffness, comfort, aerodynamics and weight in the development of the wheels, 'width' quickly became the motif at the launch in Mallorca, Spain this week.
Borrowing from big brother
The ingeniously simple hub design of the hubs featured on Zipp's 1080 wheelsets has been appropriated to provide the S series with cartridge bearing-equipped, alloy hubs with 17mm oversized axles; the intention to spread load as close to the dropouts as possible for maximum stiffness. For the same reason the three-pawl rear hubs employ a radial spoke pattern - called Rx1 - on the drive side to take advantage of the several millimeters of spacing denied by laced patterns.
The Sprint and Race models benefit from Zipp's proprietary Hybrid Toroidal rims. The 30mm rim profile flares out in a curve beneath the braking surface to match the tyre profile and reduce drag. The use of low profile hubs was another tactic employed in an effort to cheat the wind.
Internal alloy nipples also serve to smooth the profile and appearance of those wheelsets, while the Comp model incurs a weight penalty through the use of external brass equivalents. Sapims's steel spokes were employed by SRAM in an effort to achieve a level of comfort and durability across the range.
The entry level S27 AL Comp offers a 27mm v-shaped welded alloy rim paired with a SRAM Comp hub via Sapim CX spokes. At a suggested retail of US$500, they weigh in at 1620 grams (735g front, 885g rear) and will be offered in a brushed black finish.
The S30 AL Sprint take back 125 grams (1495g - 680g front, 815g rear) on the Comp through alloy nipples, Sapim CX Sprint spokes and internal machining on the rear hub. A black mirror finish is enhanced by baked-on decals with the pair set to retail for around the US$750 mark.
The S30 AL Race are also adorned with baked-on decals and a new black chrome finish dubbed 'Black Diamond'. Beyond their outward appearance the Race trim the package down to shave a further 65 grams (1430g - 645g front, 785g rear). The savings are made with more machining inside the rear hub and the use of Sapim CX Rays spokes. The top end of the S range, they will retail for US$999.
All three wheelsets are clinchers, and while SRAM would not rule out the implementation of tubeless technology in the future, company representatives said there were no immediate plans to introduce it to the wheel range.
Production on the wheels began last month, with shipping expected to begin in the northern spring.
The wheelsets that started it all for SRAM last season, the S40, S60 and S80, will continue into 2011. The current 3K carbon weave has been replaced with unidirectional carbon fibre; with a weight saving of 30-40g per pair the net result. All three wheelsets will be offered in two colour schemes: Red Race (red and white decals) or Black Stealth (silver and white decals).
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