SR Suntour Auron Fork - Review

Construction

The Auron's lowers are constructed from magnesium, and the 34mm 7000 series aluminum stanchions are bonded to a hollow aluminum crown. The fork is only available with a tapered steerer tube and is equipped with a 15mm thru-axle that uses SR Suntour's Q LOC 2 system. The arch of the fork shares a similar shape with Suntour's Rux downhill fork – it's fairly thin vertically, but has more horizontal width than other forks on the market. There's plenty of room to run up to a 2.5” tire, and the back of the arch is smooth, free from any lattice work that can pack up with mud on sloppy rides. Disc brake calipers are mounted onto a post mount that will accept 160mm rotors without the need for an adaptor.


Damping / External Controls

The Auron has an air spring with a coil negative spring on the left side of the fork, and a sealed cartridge damper is located in the right side. Suntour chose to go with a sealed cartridge due to the ease of service – a cartridge swap can be done in a matter of minutes, providing that a shop has a replacement in stock. The possibility of contamination from mud and grit working its way past the fork's seals is also less of an issue, since the oil is all contained in one sealed unit.


The fork's air pressure is adjusted via a Shrader valve found under an aluminum cap on the left side of the fork, while high and low speed compression can be adjusted by turning the two knobs on the top right side. There are 14 clicks of high speed and 10 click of rebound adjustment. Rebound adjustment takes place at the bottom of the right leg by turning a red anodized knob. There's also an elastomer volume spacer found underneath the air cap that can be trimmed down to decrease the amount of ramp up at the end of the fork's travel.


Q LOC 2

The Auron uses SR Suntour's patented thru-axle quick release system called the Q LOC 2. Instead of threading into one side of the drop outs, the axle has a portion that expands once it's through the dropout, and then the quick release lever is closed to secure the wheel. Wheel removal is as simple as opening the QR lever, pushing in and turning the nut on the thru axle, and then sliding the axle out. It does take a few practice runs to get the hang of the system, but once you figure out the concept it's a quick and easy method of securing the front wheel.

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Ride Report

Our test fork spent time on two different 160mm full-suspension rigs, each originally specc'd with a different suspension manufacturer's 160mm fork. On the trail, the Auron has a very uniform, consistent feel through the initial 3/4 of the its stroke, followed by a strong ramp up as it nears the end of its travel. There's not the beginning stroke suppleness that's the hallmark of a coil sprung fork, a trait that several air forks currently on the market have been able to come extremely close to replicating. SR Suntour does use a coil negative spring on the air side of the fork to help increase the fork's initial sensitivity, but it still wasn't quite as supple over the small bumps as we would have liked. After a few rides we decided to trim the elastomer spacer down a bit since we weren't using the full amount of travel, even of off larger drops. Trimming the spacer is a quick process, but it's a measure twice, cut once type of affair, and it seemed like a fairly rudimentary way to adjust the air chamber volume - some type of reusable plastic spacer system would make more sense. Trimming the elastomer did the trick though, giving the fork a less harsh ramp up and increasing the amount of useable travel.

Although we weren't floored by the fork's initial suppleness, its performance was consistent, and there wasn't any odd behavior even when it was pushed hard through sections of jagged rocks or wheel grabbing, root filled holes. Even after the elastomer spacer was trimmed down, the Auron did a good job of managing hard impacts, and there were no teeth-rattling, harsh bottom outs on those occasions when we landed further and flatter than planned. Although the Auron does have a wide range of compression settings, we seemed to fall at the far end of the adjustment spectrum, and ended up running the high speed compression all the way open, with only a few clicks of low speed. Heavier riders may find the compression settings to be more useable, but it would be nice to see the amount of damping in the full open position reduced to expand the range. As far as chassis stiffness goes, the Auron falls in the realm of what you'd expect from a fork with 34mm stanchions, although it did feel slightly less laterally stiff than the RockShox Pike whose place it took on our test sleds. Still, riders making the jump to this fork from one with 32mm stanchions will no doubt notice (and appreciate) the added stiffness.


Issues

The first bike we tried to install the Auron on had a set of wheels laced up with Shimano XT center lock hubs. After getting the fork and brake all set, we put on the front wheel and gave it a spin, or at least tried to – the center lock lockring contacted the lower part of the fork leg, a design oversight that meant the Auron wouldn't work with center lock hubs. We spoke to Suntour about this and they said that fewer than 50 forks had this issue, and that the design had been corrected for the current production run.

The other issue we ran into occurred on demanding sections of trail where the fork was cycling quickly through nearly all of its travel. In these instances the rebound stroke noise became very pronounced, emitting a sound reminiscent of a fat kid trying to suck the last bits of a milkshake through a straw. It's not something that affects the fork's performance, but it's loud enough to be distracting, and was even more noticeable thanks to how quiet modern bikes have become.


Pinkbike's Take:



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