SRAM RISE mountain bike wheels – First look
By Zach White in Nice, France | Friday, October 7, 2011 9.30am
SRAM have launched their first mountain bike wheels; this is the carbon-rimmed RISE 60 Zach White/BikeRadar
SRAM have unveiled their first mountain bike wheels – the carbon-rimmed RISE 60 and aluminum RISE 40. Two years in the making, both sets feature asymmetric 19mm-wide, 26mm-deep rims, fast-engaging rear hubs and a choice of axle fitments. They'll be available in both 26in and 29in versions.
According to SRAM's wheel product manager Bastien Donze, the company had one aim for their first cross-country hoops – they “wanted to build wheels that ride well". "This sounds obvious," he said. "But it's trickier than it sounds.” SRAM's designers came to the conclusion that balance is the key to great mountain bike wheels. They identified six main factors that had to be addressed – weight, inertia, engagement, lateral stiffness, frontal stiffness and efficiency.
At the top of the list was weight, so SRAM kept the materials used as lightweight and minimal as possible, while still maintaining durability. The 26in RISE 60 weighs 1,330g, with the 29er version tipping the scales at a respectable 1,420g. The RISE 40 wheelsets weigh 1,710g and 1,840g, respectively.
Hub engagement was seen as the next key attribute and SRAM's solution for the RISE 60 (the RISE 40 has a standard freehub) is impressive. Using a 54-tooth ratchet ring in the hub body and three pawls in the freehub that each have three teeth, the mechanism features nine purchase points. The increased number of teeth keeps engagement down to a respectable 6.7 degrees, allowing a very snappy reaction.
The RISE 60 rear hub features three pawls that each have three teeth to clutch the 54-tooth ratchet ring
SRAM have addressed lateral stiffness in several ways. Firstly, they say a 2.5mm offset in the rims allows for more balanced spoke tension. Spoke angle and lace pattern have also been selected with stiffness in mind – the wheels are each built up with 24 bladed, straight-pull spokes, laced two-cross; the RISE 60 gets Sapim CX-Ray spokes and alloy nipples, while the 40 is built with cheaper stainless steel spokes and brass nipples.
Both front wheels are interchangeable between standard 9mm quick-release skewers and 15QR through-axles via different side caps. Surface area of the 9mm side caps has been bumped up from the standard 19mm to 31mm, increasing lateral stiffness by a claimed 15 percent. These side caps are only designed to work with RockShox suspension forks and, according to design engineer Jesse Jakomait, 31mm is as large as SRAM could go without rotor interference.
Use of oversized axles and wide placement of the hub bearings adds further resistance to lateral forces. Despite these efforts to keep the wheels stiff, SRAM say the RISE rims are designed with the right amount of give to reduce dents and flats, and increase ride comfort. This is aided by the steel spokes and lacing pattern. Returning to the axle fitment theme, the RISE 60 rear wheel can be swapped between 9x135mm and 12x142, but with the 40 you have to pick one or the other.
Straight-pull Sapim spokes keep weight down and durability up on the RISE 60 wheelset
Neither the 6000-series aluminum or carbon RISE rims are tubeless-ready, but both are compatible with tubeless conversion kits. The RISE 60 wheelsets we rode at SRAM's media camp in southern France were set up tubeless and held up well over the 60+ off-road miles ridden. SRAM’s Paul Kantor told us they’re working on their own RISE-specific conversion kit.
First impressions of the RISE 60 are that SRAM have introduced a very good wheelset. Hub engagement is probably the most noticeable improvement over other wheels out there, as pressure applied to the pedals is almost instantly transferred to the wheel. The lightweight carbon rims took the edge off long, steep climbs, and felt snappy through accelerations.
Lateral stiffness felt appropriate with our 15QR up front and 135mm QR in the back, too. The only slightly disappointing thing was that the logo and graphic decals on the rims were already showing signs of wear after a couple of long rides. SRAM are aware of this and say they’re working on a better option.
The RISE 40 wheelset will cost $550/€465. It's already on the production line and should be shipping from Taiwan later this month. The $2,000/€1,800 RISE 60 is still several weeks out, with ETAs of early December for the 26in version and sometime in February for the 29in version. The carbon rims will be manufactured and assembled in SRAM’s Indianapolis facility alongside SRAM and Zipp carbon road rims.
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SRAM make the carbon RISE 60 rims in their Indianapolis factory alongside their carbon road rims
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