How many crowns does one princess need? Well, the new Öhlins RXF38 m.2 reportedly achieves similar riding characteristics to their dual-crown DH38, in a smaller and lighter-weight package. The 170mm 29er fork we tested tips the scale a touch less than a Fox 38 and it further cuts grams and complications with a brake-caliper mount for 200mm rotors. It’s only available for 29″ wheeled bikes with up to 2.6″ tires and the air spring can easily be adjusted to 160, 170, or 180mm of travel.
Test pilot profile height: 5’9″ (175cm) weight: 145lbs. (65kg) testing zone: Northern Italy and Bellingham Washington
In addition to the 38mm stanchions and burly chassis, this fork has a clean look and minimal moving parts. There are high and low-speed compression controls, low-speed rebound, two air chamber valves, and no bleeder valves in the lowers. The floating axle is secured with a second pinch bolt to minimize friction and prevent it from loosening on the trail, similar to that of the Fox 38. The fork we tested came with a 51mm offset, and the fork is also available in a 44mm offset option.
One might think that with two air valves to adjust this fork would be a hassle to set up, but that pair of valves arguably makes things simpler. The main chamber works like any other, allowing riders to add air until the fork rides and sags the way you like it to. Then, the ramp-up chamber adjusts the pressure needed to support the fork through the final third of its travel, and it’s both more adjustable and simpler than removing the air spring cap to swap volume spacers. In a matter of seconds, riders can dial in ramp pressure to suit trails conditions for a given day.
Alongside the supportive air spring, this DH-developed TTX18 damper is equal parts simple and effective. The high-speed compression offers just three positions for soaking up the hardest hits, and it covers all of the damping range most riders could want. I’ve been keeping it one click from fully open for most riding, sliding it to the two-thirds-closed mark when the soil sea becomes extra choppy. The detents in this larger lever are difficult to feel, which isn’t the norm with Öhlins equipment. The low-speed compression knob is just as effective, producing a noticeable change between its fifteen clicks. Dialing in the grip side of compression is as easy as most other forks, and I was able to adjust it by checking for brake dive at home and then fine-tuning things in the forest. The rebound knob is as simple to dial as any, and its range of seven clicks covers all the return speed you could need.
Long-travel bikes are largely designed with seated climbing in mind today, which explains the lack of a lockout switch on most modern forks. There’s no need to lock the fork if you’re not standing up pulling on the bars for the whole climb. Riders who miss having that switch will appreciate the large HSC lever on the RXF38. When it’s fully closed it acts similar to a traditional lockout, significantly stiffening the fork for lung-burning climbs. It can quickly be flipped at the base and peak of a climb without excessive fuss. Climbing with this burly fork on a heavy gravity sled requires a few extra calories, and the ability to stiffen it up could make those transfers a tad less taxing.
|Travel||160, 170, 180mm|
|Brake mount||200mm to 220mm max|
|Max tire size||29 x 2.6″|
|External damper adjustments||LSR, LSC, HSC|
|Air spring adjustments||Main chamber and ramp-up chamber valves|
Trail chatter, body-weight shifts, and any other forces that the low-speed circuit regulates are well managed with this new fork. It feels every bit as smooth and grip-capable as the Fox 38 that I tested earlier this year, even with a fairly stout summer setup. The first third of its 170mm feels less linear than the Fox, and it definitely holds its height better than the Kashima-coated fork. The Fox seemed to ride low no matter how much air I added, and this fork holds a healthy posture to better maintain the bike’s geometry as the axles move.
Mid-stroke support is one place where the RXF38 clearly pulls ahead of its competition. You can push into the bars as hard as you want and, with correct sag and ramp-up pressure, it will return with all the pop you’re searching for. It’s one of the most supportive forks I have tested to date, and I would highly recommend it to anyone who likes to descend their roughest trails as fast as possible. Some forks have a segment of their travel that feels wishy-washy, but this one maintains its ready composure throughout the stroke.
When you land in a mess and really need the suspension to be ready for what’s coming, the RXF38 has your back. Before riding this black and yellow pogo I hadn’t experienced a fork that felt good at every point in its travel, and this model provided some pleasant surprises. The air pressure settings that Öhlins recommends are laughably low, as they are with most forks. Once I stopped paying attention to their numbers and focused on the trail feel I was able to dial in the ramp-up so that the fork rarely bottoms out while using roughly 90% of its travel. I like to keep a 10mm buffer just in case, which also provides just the right amount of rebound spring for a quick return from full compression. Bikes with forks this long are made for plowing stone fields, and this fork is certainly up to the same task as the frame it’s mounted to.
Like the Fox 38, I’m not a large enough human to say if the fatter 38mm stanchions are worth their increased stiffness. What I can say is that this fork tracks the ground as precisely as its closest competition, allowing the rider to select a desired line and stick to it. It’s not so stiff that lighter riders like myself will have issues with deflection or overall rigidity. I am fortunate to only experience hand and forearm pain with a few forks, and this one is forgiving enough to keep those muscles and tendons happy. A chassis that’s too stiff can also result in traction issues, and the RXF38 has no problem helping the tire find its grip.
While the service intervals are a little shorter on this fork, the lower leg service is about as simple as it gets. There are some helpful tricks in the brand’s maintenance videos that will be useful when working on any fork. You’ll want to take a peek at the oil specifications during service, as the RXF38 uses less fluid than a lot of forks and the damper side uses damper fluid in place of standard fork lube.
Whether you prefer a supportive race feel or a comfortable trail-paver up front, the RXF38 can be dialed to make that experience possible. It is a bit more expensive than some of the competition, and if you have the cash to spend its consistent high performance is definitely worth considering.
- One of the most supportive forks we’ve tested thus far
- Fully useable damper adjustment range
- Super simple service
Pros and cons of the Öhlins RXF38 m.2 fork.
- No fender included
- Service intervals might be too short for some folks
- Weight may not justify performance over the RXF36 depending on the rider