Öhlins RXF38 m.2 review: for proper hard charging

Using all the data gathered from the original m.1, and using input top level athletes, Öhlins designed the RXF38 m.2 from the ground up as a brand new fork, intended to be raced on the steepest and roughest tracks in the world. Designed for 29in wheels only, the RXF38 m.2 is available with travel ranging from 160mm to 180mm, with 51mm or 44mm offsets and it costs… £1,450.

We’ve had a set 170mm 44mm offset on test for the last couple of months to see what they’re all about. 

Construction

The RXF38 m.2 is unmistakably Öhlins. With signature black stanchions (obviously 38mm diameter) sliding into chunky black lowers and the easily recognisable gold and blue adjusters sat on top. The 38mm stanchions have been engineered to offer a “perfect flex pattern under braking, cornering and on impact”.

The right hand leg holds the air spring. Unlike a lot of other manufacturers uses a three chamber system.

Like most forks on the market, the RXF38 m.2 does have positive and negative air chambers that are filled from the valve at the top of the leg and self equalise through port. 

Where these chambers differ though is how they offer adjustment. They forgo the use of tokens or volume spacers. Instead the fork uses a third ‘ramp chamber’ that is situated at the bottom of the leg and is adjusted via a valve on the bottom.

The supposed advantage of this design is the ability to easily make infinite adjustments to both the main and the ramp chambers. Rather than having to get your toolkit out and install/remove spacers. The infinitely adjustable nature of air is also handy if you feel you’re ‘between’ volume spacers (it saves hacking volume spacers in half with your hacksaw).

Inside the left leg you’ll find the damper. The RXF38 m.2 usus the brand’s signature TTX18 damper which uses a twin tube system – one inside another. This is designed to provide easy circulation of the oil from side of the piston to the other and avoiding any potential cavitation.

The damper is an evolution of the damper found in the DH38 downhill fork, but has been adapted to fit a single crown platform. It’s also tuned for enduro racing, where reducing fatigue is a (small) concern, as well as all-out race pace. The damper piston is 18mm (the clue is in the name) which Öhlins say is optimised for small bump sensitivity. More about this later.

To add to the general slipperiness, the RXF38 m.2 uses blue SKF seals to keep stiction to a minimum. As with the RXF36, the fork features a pinch bolt on the axle for added security and to keep things running true.

Claimed weight is 2320g, which was bang on, on our workshop scales. 

Tunability comes in the form of three different dials to play with. There is a rebound adjuster offering 15 clicks of rebound compression which can be found in the bottom of the damper leg. Then you have low speed compression adjustment which offers 16 clicks. Finally, a three position high speed adjuster which acts as a platform and an almost-lockout. Both these controls can be found on the top of the damper leg.

Setup

Initial setup of the forks is pretty straightforward. Öhlins has a handy initial set-up guide on its website. Simply enter the bike you are riding, input your weight and preferred sag setting, and it will give you a list of suitable products along with base air pressure settings for both the main and ramp chambers. 

For my bike and weight, Öhlins suggests that I go with 105psi in the main air chamber and 185psi in the ramp chamber. It’s important to note that you should also fill the ramp chamber first. This gave me the 20% sag I was looking for.

It was then just a case of setting the low speed compression. I set this around the middle point and then gradually worked back until I ended up running just a couple of clicks.

I ended up running the rebound just a couple of clicks in from fully open. 

Performance

The fork has spent the test period plugged into the front of my RAAW Madonna V2.2.

Giving the fork the obligatory ‘car park bounce test’ it felt really plush off the top. It seemingly doesn’t take much to get the fork moving through the initial part of its travel, with little break away force required.

During that first ride though I felt that while the fork felt great on flowier trails, it didn’t have the support I was looking for on steep and harsh tracks, or when hitting fast turns. I experimented with different air pressures in the ramp chamber to add some additional support in the middle of the travel and settled a bit above the recommended settings, at around 210psi. 

I kept the main chamber the same and this gave me the additional support I was looking for, while keeping the same sag. With that small change, the fork sat up in its travel a bit more on steep tracks and when hitting fast turns. On fast flowy trails the RXF38 m.2 offers plenty of support in the mid stroke for pumping downslopes and popping off lips and lumps, remaining supportive in the middle of the travel and not feeling wallowy. 

On high speed, smaller frequency repeated hits – like washboard hardpack or carpets of roots where you’re in the initial part of the travel –  the RXF38 m.2 does a decent job of dealing with them, but doesn’t make them magically disappear like some other forks do. It certainly mutes the feedback though, and offers a good amount of grip across off cambers and root sections, but you still feel what’s under the front wheel. 

When things start to liven up a bit and and you’re further into the travel, the Öhlins RXF38 m.2 starts to shine and make more sense. On bigger, faster hits, it feels properly smooth, but stays supportive, and holds a line through the chunkiest and roughest tracks, without getting deflected. You can point it where you want to go, get off the brakes and let the fork get on with it.

That support also plays its part hitting fast turns and when things get steep, with the fork working nicely in the middle of the travel to absorb impacts and stay composed, but still having plenty left in reserve for hitting catch turns or getting you out of trouble. And while it feels like it’s offering loads of support, it’s still willing to use the full amount of travel on offer. 

I’ve found myself using all 170mm on a lot of rides, yet never really ‘knowing’ that I had as it is never a harsh bottom out – it’s nice and controlled. Which isn’t the same with all forks. Previous to fitting the Öhlins I had been running at Zeb at 170mm and I very rarely saw the o-ring hitting the top of the stanchions.

While I couldn’t detect any noticeable flex, whether smashing through rocky chunder, or hard on the brakes in a steep tech chute, that’s not to say it isn’t happening. Rather it’s doing what it needs to with no excessive flexing. 

Obviously, as a single crown enduro fork, the Öhlins RXF38 m.2 will be pedalled up to the top of the trails under your own steam, and it does it without issue. There’s no excessive bob and the fork just gets on with it. I tried the fork in all three of the HSC settings and ended up just running in the first one. While they certainly do alter the feel of the fork, more than  just an on / off lockout, I didn’t feel the need to change even when climbing.

Overall

The Öhlins RXF38 m.2 is a great fork in the right conditions. It’s a little less floaty-fast plush sensitive in the initial part of its travel than some of its rivals but for proper hard charging it’s an impressive piece of kit. While it might not be the most sensitive option out there (it is squarely aimed at going eye-wateringly fast on the hardest tracks in the world), when pushed hard, it works really well.

It offers pretty unlimited scope for raceday tweaking if you’re needing to go as fast as possible with gravity but against the clock. It comes at a pretty hefty price though.