In 2011 SR Suntour’s suspension forks won three world championships, five World Cup races and made 15 World Cup podium appearances – stats that put the brand right up there with Fox and RockShox. For 2014 the Japanese company are working on two new products – the air-sprung Rux downhill fork and a new version of the Axon for 650b wheels – that may help them break into what’s so far been an untapped market for their suspension: North America.
Suntour once went head-to-head with Shimano as a manufacturer of off-road components, but that was in an era of thumb shifters and first generation suspension forks. After combining with SR in the late 1990s, they cornered Europe’s treking/hybrid suspension segment and have gone on to dominate the entry-level mountain bike fork market. They’re still best known for OE forks that are supplied with complete bikes rather than sold aftermarket, but 2013 looks to be a turning point for the company, as with fellow upstart suspension manufacturer X-Fusion.
Rux: 6lb downhill dual-crown
The Rux, which was first shown at the 2012 Taipei Cycle Show, is a 200mm-travel, fully featured dual-crown downhill fork that keeps step with the latest and greatest from the industry’s leaders. It features 38mm0diameter 7050-T6 aluminum alloy stanchions, magnesium lowers with a unique 20mm quick-release through-axle, a direct 200mm post-mount brake mount and integrated brake line hanger.
20mm axle for the Rux, with tool-free provisions on the drive side
Internally, the Rux uses an RC2 damper cartridge similar to that found in Suntour’s Durolux forks. This offers externally adjustable high and low speed compression damping, as well as rebound. It’s part of Suntour’s QSP (Quick Service Product) program, which means it’s entirely self-contained, user or shop serviceable, and if all else fails, easily replaceable.
“At its core it’s about ease of maintenance but there’s no shortcut on performance,” said Darren Salsbury, who’s part of SR Suntour’s North American product development team. “This cartridge damper philosophy is over 10 years into its development process. The QSP cartridges separate damping oils from the lubrication of the fork’s bushings also, so they don’t need to be serviced as often as open bath type designs. The QSP cartridge is also an ‘upside down’ design so the unsprung weight is kept to a minimum.”
The Rux will be air-sprung, to save weight and allow easier adjustment. A simple, spacer-based system will allow users to alter air volume as well as air pressure, using just an open ended wrench and a shock pump. This means racers can quickly and easily fine-tune the progressivity of the fork to suit different courses.
Volume of the air spring can be adjusted by removing the valve assembly and adding or removing some of the five spacers
Suntour have 50 pre-production forks out in the wild for ‘real-world’ testing. They’re playing with different crown shapes, as well as a tapered steerer tube. Rider feedback, overall performance and durability over the course of this season will determine when the Rux hits the market; we expect a date and price to be set in time for this fall’s trade shows. As a 2014 modelyear product, it’s likely to hit shops sometime next year.
Axon RC Werx 27.5: Cut-to-fit carbon legs readily accept the middle wheel size
Suntour have had huge success on the World Cup cross-country circuit with the Axon Werx RC fork (US$1,099 with tapered steerer), which combines ‘Carbon Hybrid’ lowers with a hollow forged 7050-T6 alloy crown, steerer and 32mm stanchions. The lowers – which consist of a carbon fiber arch and legs, with bonded magnesium dropouts – are said to be roughly 65g lighter than the cast magnesium equivalent.
The same lowers are used on a 29er version of the Axon Werx that’s been in race testing for the past year and is due to go into production soon. In fact, Suntour now produce just one set of Axon Werx lowers, which come out of the mold at a length suitable for 29in wheels and are cut to fit 26in wheels if necessary, before the magnesium dropouts are bonded on. This means it’s very easy to adapt the fork for 650b (27.5in) wheels.
The prototype uses Suntour’s RL-RC remote adjust damper
Suntour were showing a middle wheel sized Axon RC Werx prototype at the Sea Otter Classic, fit with their RL-RC damper cartridge, which has an adjustable compression circuit and cable-operated remote lockout (the standard Axon is also available with an electric-motor-assisted ELM lockout). The 27.5in fork’s availability ultimately depends on bike manufacturer (OE) acceptance. As with the Rux, Suntour will provide more details this fall.