Vital Rides the All-New Öhlins RXF36 Fork and TTX Air Shock 4

Bottom-up redesign brings new performance to Öhlins' trail and enduro mountain bike suspension line.

Vital Rides the All-New Öhlins RXF36 Fork and TTX Air Shock

In their own words, Öhlins built their company on damping expertise and coil. It seemed like almost a foregone conclusion when the company’s first MTB product, the excellent TTX 22 M proved to be everything we expected from the Swedish suspension specialists, but as they turned their attention to air springs, things got a little trickier. The RXF series of forks was often lauded for overall stiffness and the quality of damping on offer, but sticky bushings and a problematic air spring tune kept it from delivering to its full potential while the STX Air shock had a spotty service record. There were clearly things that Öhlins could do better here, and that is just what they set out to do with the all-new RXF 36 Trail fork and TTX Air shock. We headed up to not-so-sunny Sweden to find out more and to put the new stuff to the test, read on to find out how we got along.

Öhlins RXF 36 Highlights

  • TTX-technology
  • Travel: 120-180 mm (air), 130 -170 mm (coil)
  • 36 mm stanchion diameter
  • Independent spring system
  • Independent damper system
  • Retuned air spring system
  • Overall improvements for reducing friction
  • Offset 27.5: 46 mm or 38 mm
  • Offset 29: 51 mm or 44 mm
  • Compatible maximum tire sizes: 29x2.8 / 27.5 x 2.8 / 27.5+ x 3.2
  • Prepared for mudguard
  • Race proven setting bank
  • MSRP: $1125 USD / 1140 EUR excluding taxes (US sales tax, EU VAT)
  • Availability: March 2019

Öhlins TTX Air Highlights

  • TTX-technology
  • Adjustable low speed compression
  • Adjustable rebound
  • High speed compression adjuster
  • Climb mode
  • Air spring volume spacers included in kit
  • Metric: 190/210/230/250 mm lengths
  • Trunnion: 165/185/205/225 mm lengths
  • MSRP: $780 USD / 702 EUR excluding taxes (US sales tax, EU VAT)
  • Availability: November 2018 (Specialized), December 2018 (aftermarket)

A few months ago we tested the all-new DH38 fork which Loic Bruni subsequently used to become World DH Champion for the third time in his career (that article also includes more on the company backstory). Although we only rode that fork for a couple of days at the time, it became obvious that Öhlins had made significant steps forward when it comes to air spring technology and mountain bike fork manufacturing in general. Knowing that they had some ground to make up in the enduro bike market as well, it came as no surprise when they invited us back to Sweden to check out the all-new RXF 36 Trail fork and TTX Air shock.  

With the extensive development work done on the DH38 and now the new RXF and TTX Air, the team feels that they have matured to the point of really knowing what they are doing, and the fact that it only took them a couple of years to start winning titles at the highest level is testament to how seriously they are taking this challenge.

Minus the new graphics, the new RXF 36 Trail fork looks fairly similar to the previous version, but looks can be deceiving – as can a name! “Trail” is not the first name we would have thought of for the new fork, as “trail” generally implies a less aggressive product than “enduro” and the latter is certainly the application that the new fork is taking aim at. Be that as it may, here is a quick overview of the improvements made to the new fork:

  • Starting with the chassis, there is more clearance for bigger tires, and there are now two offset options for each wheel size.
  • Bushing play has been optimized following race team feedback, while SKF wiper seals provide less friction and better performance in wet conditions.
  • The crown is stiffer thanks for different machining and a deeper steerer interface.
  • The stanchions feature an improved surface treatment for better resistance to wear.
  • All-new twin tube, 18mm damping cartridge.
  • Retuned air spring featuring larger negative air chamber.
  • Lighter steel spring on coil version.

That is an impressive list of changes, meant to address the points of concern sometimes raised about the previous version of the fork. Öhlins freely admits that mountain bike air springs were a challenge for them, especially given the constraints of low weight and performance characteristic sought in this particular market. With the extensive development work done on the DH38 and now the new RXF and TTX Air, the team feels that they have matured to the point of really knowing what they are doing, and the fact that it only took them a couple of years to start winning titles at the highest level is testament to how seriously they are taking this challenge.

Looking through the list of changes of the new fork, “larger negative chamber” on the air spring stands out as a move that the big players in the market have already made for their 2018/2019 product, although Öhlins told us that they “didn’t go crazy with it” as they feel a happy medium is what is needed here to meet the demands right across the travel range. In terms of adjustments, the air spring offers a self-equalizing negative chamber and an extra ramp up chamber that helps tune the spring curve at the end of the stroke. Note that the air spring is a self-contained cartridge that does not use the inside of the fork stanchion for the main air chamber as many competitors do - this means it's easy to change between coil and air springs, without risking damage to the inside of the stanchions which could cause air leaks. On the topic of springs, the coil version of the fork uses new springs that are 10% lighter than before.

For those who want to go beyond the norm, the air volume of both air chambers can be further adjusted with spacers (requires opening up the internals). As for the damping side, the move to a smaller, 18mm piston is said to help with small bump sensitivity, and the damping curves have been tuned for trail and enduro riding on this new fork. Somewhat confusingly, the pedaling platform is activated via the high-speed compression lever, but that last step actually closes off the low-speed compression circuit as well (which explains the shape of the high-speed compression curves seen below).

Looking at the new air shock, the major news is of course the move to a twin tube damping layout (the previous STX Air shock used a single tube design), making the TTX Air the true heir to the impressive TTX 22 M coil shock.

We're big fans of the TTX 22 M coil shock and we're excited to see the same damping tech find its way onto the new air shock.

Öhlins told us they were somewhat surprised to learn that on many mountain bike frames the shocks are a structural part of the rear linkage, and that as such they absorb quite a lot of side load and bending forces. This caused the STX shocks to develop longevity issues in some cases, which was one of the reasons for the reliability issues seen on that shock. The new TTX Air has been designed specifically to deal with these types of situations, with increased bushing overlap, improved wiper seals, and a more robust construction of the air spring.

Low-speed compression and rebound are adjusted with an allen key...
...while high-speed compression and climb mode are adjusted with a lever.

In developing the TTX Air, Öhlins focused heavily on friction, and how to reduce it. They’ve introduced a new lubrication and grease, as well new dynamic seals from Trelleborg with optimized seal preload. The result of all the design changes and new features is a significant reduction in friction and an improvement in service life.

The Specialized version shown here features a smaller air can.

When it comes to tunability, the TTX Air offers external high-and low-speed compression adjustments, low-speed rebound adjustment, and adjustable air volume. The standard version of the TTX Air can take up to ten “tokens” while the smaller air can developed specifically for the Specialized Enduro can manage four (the Enduro is a very linear bike, so it requires a smaller overall air volume which explains the special version). The tokens mostly affect the ramp up at the end of the stroke.

On the damping side, Öhlins says that the twin tube layout removes the risk of cavitation and allows the shock to work with the lowest possible internal oil pressures, with isolated control over the different compression and rebound circuits. Ultimately, the goal of the damping technology is to provide improved grip, tire feel, and wheel control. Independent adjustment of high- and low-speed compression as well as low-speed rebound should allow most riders to tune in the feel and the performance they like. As always, Öhlins aims to provide a fully usable range of tuning, so that even if you twist the knobs all the way open or closed, you should still have a ridable product. As with the fork, the high-speed adjustment lever on the shock features a climb or lockout position which actually closes off the low-speed circuit as well (a little bit confusing to get your head around at first, but it works well enough and removes the need for another dedicated lever).

Standard size air can version of the TTX Air.

On The Trail

To give us the opportunity to test the new goods out in real life, Öhlins whisked us away to the small but fun bike park in Järvsö. We only had one day on site, and some nasty weather made it a bit shorter than planned as well, but we still got enough runs in to form a first opinion. We chose to ride a Specialized Enduro with the TTX Air in the back and the RXF Trail Coil up front. Setting up was straightforward, once we had our sag dialed in we twisted a few knobs and headed up the lift.

Charging into rough terrain or bigger hits never seemed to faze the fork, and it showed off an impressive amount of sensitivity and control.

From the get-go, we found both the fork and the shock easy to get along with. Charging into rough terrain or bigger hits never seemed to faze the fork, and it showed off an impressive amount of sensitivity and control. Of course, you’d expect nothing less from a coil fork, but we’ve tested the previous version and the new RXF Trail is a significant improvement in general “slipperiness”.

Playing around with the knobs revealed plenty of range to make finer adjustments to the behavior of the damping. We were particularly impressed with how smooth the transition from compression to rebound feels, and the general level of poise on display. Simply put, neither the fork nor the shock felt overwhelmed at any point, even when we got ourselves into stupid riding situations we’d rather have avoided.

Stiff and supportive, the RXF 36 Trail charges hard but also plays nice.
Lots of room for bigger tires - shown here a with a 29/2.3.

The rear shock version we tested here was developed specifically for Öhlins’ exclusive OEM partner Specialized. It features a smaller air can to compensate for the linear nature of the Enduro’s linkage. On the ground, we were impressed with how well it all worked out. The shock offers plenty of sensitivity while handling the bigger stuff like a champ. With short runs in cold weather it was obviously not the best place to test for any heat build-up or damping fade, but based on our previous experience with Öhlins’ twin tube designs we’d not expect any significant issues in this regard.

One day of testing is obviously not enough to form any definitive opinions, and the logistics of the situation also left us unable to squeeze in any time on the air version of the fork. Even so, the improvements carried out by Öhlins definitely seem to have borne fruit, and it feels to us like the enduro/trail line-up is now in the right place. We are expecting some long term test samples to arrive shortly, so we’ll come back with a full review after we put the miles in. In the meantime, head on over to www.ohlins.com for more.


About The Reviewer

Johan Hjord - Age: 45 // Years Riding MTB: 13 // Weight: 190-pounds (86kg) // Height: 6'0" (1.84m)

Johan loves bikes, which strangely doesn’t make him any better at riding them. After many years spent practicing falling off cliffs with his snowboard, he took up mountain biking in 2005. Ever since, he’s mostly been riding bikes with too much suspension travel to cover up his many flaws as a rider. His 190-pound body weight coupled with unique skill for poor line choice and clumsy landings make him an expert on durability - if parts survive Johan, they’re pretty much okay for anybody. Johan rides flat pedals with a riding style that he describes as "none" (when in actuality he rips!). Having found most trail features to be not to his liking, Johan uses much of his spare time building his own. Johan’s other accomplishments include surviving this far and helping keep the Vital Media Machine’s stoke dial firmly on 11.

Photos by Matias Laurila/Öhlins and Johan Hjord

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