Long-Term Test: Öhlins RXF36 m.2

Yes, you read that right. I tested the RXF36 m.2. Öhlins did just release a 38-millimeter version of their flagship single-crown fork, but the RXF36 just has more broad appeal and applications. And anyway, I’ve been riding the RXF36 m.2 for a year, so I’ve learned a thing or two.

Öhlins has a bit of a reputation. It’s a multifaceted one, mind you, but it really just boils down to one thing—the Swedish company makes high-end suspension to make bikes go really fast. When Öhlins first came on the scene, the black and gold suspension was at the same time coveted and critiqued—the products rivaled anything else on the market when it came to performance, but at the same time, their stuff was so race-oriented that some riders didn’t jive with how it rode on average terrain.

This is a common thread in mountain bike technology that manufacturers have to navigate. While quite a bit of technology is developed on the race circuit, most riders don’t race. Especially when it comes to suspension, “performance” isn’t a metric that can be a blanket statement. It can be difficult to thread that line between a racing pedigree and the average rider.

The RXF36 m.2 is a testament to Öhlins ability to thread that line and bring race-developed and race-proven technology into something that the average rider can use and benefit from, all without losing that thoroughbred feeling. Keep in mind it’s still a fork aimed toward the racier end of the spectrum, but it’s certainly not limited to riding between the tape.

To begin on the outside and work our way in, the chassis of the RXF36 m.2 is simply stout. With 36mm uppers and a beefy CSU, the fork feels precise in a solid sort of way. It’s not overly stiff, but certainly resists the majority of unwanted twisting or fore-aft movement under braking. For general trail and enduro riding the RXF36 m.2 is certainly stiff enough, although do keep in mind that I tested the fork at 150mm of travel, which is in the middle of what it can handle–longer travel options will have more flex when extended. That’s why Öhlins made the RXF38 m.2. It’s the go-to if you’re primarily riding downright heavy-hitting terrain and wear a full-face more than a half-shell. 

At the heart of the RXF36 m.2 is the TTX18 damper, the same damper found in Öhlins DH38 and RXF38 m.2. The twin-tube damper uses, well, twin-tube architecture, which is essentially a tube-inside-a-tube layout. If you really want to dive deep into Öhlins TTX dampers, here’s a 124-page document. Essentially though, using the twin-tube design allows Öhlins to better control pressures and oil flow for more consistent and responsive damping. While the TTX18 damper uses a smaller 18mm piston, resulting in lower damping forces than the previous TTX22 damper used in earlier Öhlins forks, the TTX18 still produces more damping force than some other forks out there. Generally, harder riding (like racing) calls for more damping force, which is why Öhlins suspension has the reputation for feeling over-dampened when you’re not foot-out-flat-out. 

That being said, the TTX18 strikes a nice balance between a generous amount of damping and adjustability. Before I even dive into that further, note that Öhlins offers an expansive amount of tuning and customization—the fork ships at the firmer end of the options range, but on request, Öhlins can swap rebound and compression stacks to increase or decrease damping force. I don’t have all the data in front of me, but I’d be very surprised if there were a rider out there that couldn’t find the perfect tune working with Öhlins. If you do want all the data, Öhlins offers a “Settings bank” to customers complete with graphs, shim lists and more. Geek out to your heart’s content (and just wait for the Excel air-spring sheet coming up next!)

To take full advantage of Öhlins customizability, partway through testing I swapped out oil viscosities in the damper to effectively “lighten” the damper tune. I noticed in very cold temperatures, around freezing, the rebound circuit struggled to open fast enough. As it turned out, my test fork was shipped with an older, heavier oil weight—the RXF36 m.2 now runs a lighter oil that “lightened” the damper tune about one of Öhlins’ “settings” or damper valves. Why did I swap oil instead of damper stacks? Changing oil is a process that can be done in the garage, while Öhlins requires the fork to be sent in to change stacks. 

Once swapped to lighter oil, the TTX18 felt most similar to an original Cane Creek Helm damper, if not a wee bit firmer. With the swap, I was sitting right in the middle of the rebound adjustment range, and on bigger trails, I ran one to two clicks of HSC and one click of LSC.

Now, those settings don’t mean much out of context—so here’s context. My air-spring settings were 150psi in the main chamber and 230psi in the ramp chamber. Those are both at the far end of the Öhlins recommended pressures on the back of the fork leg, although you can run as much as 280psi in the air spring. More on that later.

In context, those damper settings mean that I still, despite running a very firm air spring, had plenty of latitude to increase damping for bigger trails. However, if I were to only ride mellower terrain, I might prefer to further decrease damping for a plusher ride. But for the riding I do, a heavier stock damping tune helped keep the fork higher in the travel and provided more support, which feels like a more “plush” ride when compared to an underdamped fork that blows through travel.

Speaking of going through travel, the air spring of the RXF36 m.2 is one of the most unique air springs I’ve ridden. That’s a good (and a bad) thing. 

First off, the RXF36 m.2 uses a three-chamber system, rather than the usual two-chamber design of most forks. There’s the usual positive and negative chamber, and then there’s also a third “ramp” chamber that serves in place of volume spacers. That ramp chamber is part of the positive chamber and is filled to a higher pressure. When the positive chamber reaches the same pressure as the ramp chamber, the ramp chamber will also start to compress. With both chambers compressing but separated by a floating piston, the effective bottom-out force is increased, kind of like what volume spacers do.

Öhlins has an Excel sheet for air spring tuning, which is not only quite fun to play with but also really helps highlight the changes between set-ups as it can plot two alternate spring curves on the same graph. See below for a peak on what my test fork’s air spring setup looks like.

On the trail, the Öhlins fork rides fairly high in its travel, noticeably higher than a Fox 36 GRIP2 or Cane Creek Helm. This is influenced by setup to a degree, of course, but after literally months of fiddling with air pressures, I consistently felt like the front end stayed higher, preserved head angle and resisted diving more on the RXF36 m.2 than the other forks. It felt like the mid-stroke of the fork, where the ramp chamber starts to engage, is more supportive than volume-spacer-based forks, which felt like their ramp-up later in the travel.

I also suspect that the easy of adjustability on the Öhlins fork really let me fine-tune a balance between a more linear spring rate without ramp up, only gradually adding pressure to the ramp chamber once I had the initial feeling dialed. On other forks, you can either add or remove a spacer (which is hard to do on a trail [unless you’re an MRP Ramp Cartridge {but then you don’t use a spacer anyway}] and takes a lot of time) which only allows adjustments in larger steps, no single PSI increments like the Öhlins. 

Where the RXF36 m.2 felt like it lagged behind other high-end fork offerings was in suppleness. At the high pressures I was running, the fork felt like it was binding and needed a sharp hit to move into its travel, like a fork that needs a lowers service. I didn’t really start to notice the phenomena until mid-test, which was when the fork was due for a service anyway. However, even after new seals and liberal Slick Honey, the RXF36 m.2 never quite felt as buttery as a Fox 36 GRIP2. The explanation I received from Öhlins on this was (paraphrasing as it was over the phone with customer support) that at higher pressures, the fork just wouldn’t be as supple off the top. Lighter riders would therefore have a plusher ride than I experienced (I’m around 220lbs). Interestingly, other forks I’ve ridden don’t suffer from reduced sensitivity at high pressures—perhaps the smaller air spring size of Öhlins, and thus higher pressures needed, play into this. 

If you’re only after small-bump sensitivity, however, the RXF36 m.2 can be run with a coil spring. The air spring is actually just a cartridge that is easily removed and swapped to a coil spring, so you don’t have to worry about scratching surfaces moving between the two spring systems, which will happen with systems like the Push ACS3 coil conversion.

I don’t have as much time on the RXF36 m.2 in its coil form, but from the rides I have done, I’ve been blown away with how plush and grippy the fork feels. Whatever Öhlins has done to reduce friction in the rest of fork has clearly worked—TTX18 damper and oversized bushings—it takes a truly minute force to move the fork into its travel. It actually almost feels like there’s play at the beginning of the stroke with how easily it moves.

The downside of running the coil option on the RXF36 m.2 is that to achieve the same bottom-out resistance as the air spring one needs to run an overly stiff coil spring. Not so stiff as to sacrifice suppleness and make the ride harsh, but stiff enough that the balance of the bike front to rear is lopsided—the front rides too high and requires you to bump up spring rate in the rear to match and feel balanced (which isn’t a great option).

In light of this, I found it better to run a lighter spring up front to make an ideal beginning- and mid-stroke, sacrificing bottom-out resistance. One can also lean on compression damping as well, in fact, Öhlins specs the coil-sprung RXF36 m.2 with a firmer compression tune for this reason.

The air spring is the better option for riders who consistently ride big terrain, where the coil option feels better on more natural terrain where traction and comfort are the top priorities.

Speaking of priorities, if you’re someone that likes to service your own suspension, the Öhlins fork is one of the most user-friendly that I’ve gotten my grubby shop paws on. I don’t work on suspension regularly by any means, rarely going beyond a lowers service, but even tearing into the TTX18 to change oil weight was a pleasant and easy experience. That’s not to mention how easy it is to swap spring systems or even just pull the lowers for service. It’s almost like they designed the fork to be rebuilt in the pits on a race weekend.

On some other nuts and bolts, the chassis of the RXF36 m.2 is the only fork I’ve run in recent years that doesn’t eventually creak at the CSU. In fact, it’s been rock solid and flex-free in the year I’ve run it. The oversized bushings do have more play than most of the forks, similar to DVO forks, but that’s a small bone to pick and one that provides the benefit of reduced friction in the system. In fact, apart from that and the air spring issue, there really isn’t any bone to pick on RXF36 m.2. 

Except maybe the price—it’s not the least expensive fork out there, at $1,250 it’s actually one of the most expensive, but you do get a lot for your money. Right out of the box it can be set up with just a shock pump and your fingers, and there are expansive tuning options for the future. With a quick rebuild, you can swap between air and coil springs to suit your ride (sold separately), and even after a hard season of riding there won’t be any creaks coming from your CSU. Öhlins has a racing pedigree and reputation for building products to suit that style of riding, but the RXF36 m.2 is a fork that really caters to any rider that wants no-holds-barred, high-performance suspension.