Inside the RXF 34
How do you get a bunch of mountain bikers really excited? One way is to tell them that Öhlins, the legendary Swedish suspension company, is jumping into the mountain bike biz with not just shocks, but also two different forks designed for trail and all-mountain use. It's the $1,150 USD RXF 34, the lighter weight of the two, that's reviewed below. The fork is available in 120, 140, and 160mm-travel options, but it's the 140mm-travel version that we've now spent nearly a full year on so we could compare it to its main competitors, RockShox's Pike and Fox's 34.
The RXF 34, which weighs 2,270 grams (5.0lbs) on our scale, employs Öhlins' twin-tube TTX damper, as well as an interesting three-chamber air spring that is claimed to allow for a massive tuning range without the need to use volume-adjusting spacers. It's certainly different, but is it better than what we're all used to using?Öhlins RXF 34 Details
• Intended use: trail / all-mountain
• Travel: 120, 140 (tested), 160mm
• Wheel size: 29''
• Three air chamber system: two positive, one negative
• Adjustments: high-speed compression, low-speed compression, low-speed rebound
• Forged, one-piece crown and steerer tube
• Stanchions: 34mm
• Axle: 15 x 100mm, non-QR
• Weight: 2,270g / 5.0lbs
• MSRP: $1,150 USD
Legend has it that simply saying the Öhlins name is enough to make the bumps feel smaller, something that no doubt comes from the company's long history of being the
name in such motorsports as WRC and MotoGP racing. And it's MotoGP that Öhlins says is the birthplace of their TTX damper that uses a twin-tube layout and is employed on all of the company's high-end offerings, including their mountain bike suspension. Part of the RXF's TTX twin-tube damper (top) and the fork's three-chamber air spring (bottom). Photo: Ohlins
Let's not get carried away, however, because the TTX twin-tube damper in the RXF is obviously very different from what you'll find inside their motorbike units, but the basic architecture is similar. Twin-tube means exactly that; the damper is a tube-in-a-tube design that sees both filled with oil and the piston working inside of the inner tube. In the most basic of terms, it is constantly recirculating the oil between the two, and it's said that a twin-tube damper creates lower internal pressures than a more commonly used mono-tube system, and lower pressures can mean more control over forces and less stress on seals. It also requires a more complicated design - there are more things stuffed into the same small space - and therefore it can be more difficult to work on. Öhlins most definitely doesn't want you to open up their damper in your garage.
The TTX setup employs a spring-backed IFP rather than a bladder like what's used in a FIT4 or Charger damper. Öhlins says that they went this route because it's not just easier to manufacture, but also more reliable over the long run while being easier for service centers to deal with when the time does come to open the system up. Air spring detail on the left, and damper piston detail on the right. Photo: Ohlins
The RXF's air spring is also different from the norm, with three air chambers rather than the usual two (one positive and one negative) that you see on other air-sprung forks. There's the usual positive air chamber, tuned via the Schrader valve at the top of the right fork leg, and it works in conjunction with a negative air spring that self-adjusts by way of a common bleed between the two. That means that if you require a lot of pressure in the positive chamber for your weight or riding style, the negative will self-adjust accordingly, much as you'll see from other air-sprung forks.
It's the third air chamber, adjusted via the Schrader valve at the bottom of the same leg, where things get very different. This is your bottom-out control, with more pressure meaning more resistance to using all of the RXF's travel, and vice versa. This third chamber does the same job as the tokens that you add or remove in RockShox or Fox fork to tune the volume, but while a socket or wrench, and of course some tokens, are required by most other forks, you'll only need a normal shock pump to get the job done with the RXF. This should make not just initial setup easier, but also changes down the road. RXF 34 Chassis
The RXF chassis is pretty straightforward for the most part. There's no funky quick-release thru-axle system, with Öhlins going with a simple bolt-on 15mm axle instead that ensures the best alignment, and a set of 34mm stanchions slide into understated lowers. There is one big talking point, however: all of Öhlins' forks feature a one-piece crown and steerer tube assembly with a built-in crown race. That's right - you don't slide a traditional crown race down over the steerer because it's already there, machined right into the top of the crown. It requires the use of a 52 x 40 x 7mm bearing, which is very common these days and also available from Cane Creek if you need to grab one. There's enough clearance at the arch for big meat, although proper plus-sized rubber would be a tight fit. You'll need a 5mm hex key to loosen the pinch bolt and back the 15mm axle out.
Öhlins aren't the first company to use a one-piece upper - X-Fusion has been doing it for quite awhile now - but what's the reasoning behind the design? It's done to remove the joint between the steerer tube and crown where the two are pressed together at the factory, a joint that can sometimes be prone to creaks and groans. Word is that it also increases rigidity, which is noteworthy for a fork with 34mm diameter stanchions that's designed for a spot of rowdiness. The one-piece construction also lends itself nicely to the built-in crown race by eliminating the 90-degree corner that could be considered a stress riser. The one-piece crown and steerer tube, complete with a built-in crown race, eliminates a joint that can be prone to creaking.
Riding the Ohlins RXF 34
Many of us are familiar with setting up a RockShox or Fox fork these days, so much so that it often takes only a few rides, turning the dials once or twice, and breaking out the shock pump a few times before you'll have a setup that feels pretty much like home. Adjusting the RXF isn't any more difficult than what's required of other forks - it's actually easier in some ways - but it's certainly different.
Öhlins recommends 100 - 110 PSI for a rider who weighs 154 - 176lbs, and since we're near the top end of that range, we started at the second figure. The ramp-up air chamber called for 150 - 165 PSI, and since it had been extremely wet, and hence the speeds were slower than they might be on a fast-rolling summer day, we went with the lower number to start things off with. This created a relatively linear setup - more so than a 34 or Pike filled with four or five tokens - but damn, it felt ideal in the slower, softer, damper conditions. The 140mm-travel RXF 34 lived on the front of a Stumpjumper, replacing a Pike of the same travel for the last eight months.
But not so much when the rain disappeared and the trails went from being wetter than the inside of a submarine with a screen door to being dusty and fast. Queue up many bottoming moments, although never once were they the kind that rattles your teeth and makes you question your grip strength. Out came the shock pump and up went the pressures: 115 PSI in the main air-spring chamber and up to 165 PSI in the anti-teeth rattling chamber. And that fettling took all of three minutes. No wrenches. No plastic spacers. It's so easy, in fact, that we ended up having different spring rates for different trails and conditions, something that caused much eye rolling from our riding buddies and many OCD jokes. The RXF's bottom-out resistance is adjusted via an air valve at the bottom of the right leg, eliminating the need to install or remove tokens. It is very effective.
With the RXF's rebound setting, when we first pushed on the fork we thought ''Oh, it must be wide open right now.'' Then we backed out the anodized gold dial and thought, ''Holy shit; it goes even quicker.'' We ended up with the fork's rebound dial set close to the middle, and while it felt lively, it didn't feel anywhere near as uncontrolled as you'd expect after giving it the ol' parking lot push at the trailhead. Low-speed compression was set with five to seven clicks, and just one to two clicks on the high-speed adjuster did the trick.
Those settings created a fork that was impressively supple at the top of its stroke and into its sag point, and while we would use all of the travel, it never felted wasted. The process took longer than with a 34 or Pike, but only because we were starting from scratch.
Sensitivity and Air Spring - The RXF 34 matches a well-looked after Pike and 34 when talking about slipperiness, and it stayed just as supple throughout the last eight months of use. Actually, because the fork's bottom-out can be adjusted so quickly to compensate, it's very easy to tune the spring rate for a given ride, say a bit softer for wet or extremely loose and dusty ground. This means that the RXF can feel more active and supple simply because the air pressure is closer to ideal for the conditions. Sure, you can certainly lower or raise the PSI on a Fox or RockShox fork, but that might also mean that, for the best performance, you might also need to add or remove tokens accordingly. With the RXF, this can be done with a shock pump in only a few minutes.
Chassis Performance - This one is easy: the RXF 34 is as stiff as it needs to be. It feels at least as torsionally rigid as a Pike or 34, and maybe just a smidge less than a 36. It never once felt like it wasn't as precise as it needs to be when pinballing through a rocky minefield or at the bottom of a steep shoot that would load the fork up with torsional forces.
Granted, at around 170lbs we're not exactly beefcakes who make everything feel a bit too bendy, but it felt more than adequate nonetheless.
Where it might have an advantage is lateral rigidity, however, as the RXF 34 displayed less of that 'tucking' feeling of the front wheel flexing backward slightly under heavy front brake loads. We don't have this complaint of a Pike or 34, though, as that's never an issue with those two forks, but the RXF seems as though it's a hair less flexible in this regard.
The lack of a quick-release axle is of absolutely zero concern to us, and we don't suspect that anyone who owns an RXF will be fussed by it, either. If you suffer a flat and don't have a muti-tool to remove the wheel to fix it, you probably deserve to have to walk out of the bush, and you probably don't have a tube on you anyway. Damper Performance
- While it's not the only thing that matters, how a fork's damper performs is probably the most important. And do you honestly think that Öhlins would f*ck this up? Not a chance. The TTX twin-tube system offers impeccable control, and it's on par with a FIT4 or Charger damper, which is saying a lot. It's probably not better in that it does everything to a high degree, but that's not exactly a diss against Öhlins when you consider how well things perform these days.
Low-speed compression control is on-point when a handful of clicks are dialed on, but the RXF could feel a bit divey through its travel if you backed the LSC adjuster out too far. On the flip side, one might call this a very useable range of damping as enough LSC could be applied to supply enough control for any type of rider, but it could also be backed off if it wasn't required. It's the same story with the high-speed compression, with a wide enough range to be called usable. The HSC lever's tab also made it simple to tweak on the fly, say if one knew that a nasty huck to flat was coming up and didn't feel like putting their wrists through a year's worth of abuse for a single impact.
Simply put, the TTX damper never feels out of its depth or at a loss for what to do during descending.
Öhlins uses the RXF's high-speed compression lever as a sort of lock-out, and while it does firm the fork up considerably, it doesn't match the firmest setting of the three positions of a Charger damper. This probably won't matter to a rider who would be considering the RXF 34, but it's worth noting if you're the kind of person who likes to lock their suspension to smash out a climb. The black dial tunes high-speed compression, while the blue dial at the center handles low-speed duties. There aren't a lot of clicks, but the effective range is quite wide.Reliability
- We saw some ''long-term'' RXF 34 reviews pop up only a few short months after the first batch of test forks were sent out, which sounds like anything but long-term to me. We've had our RXF in use for over eight months now, which is probably just long enough to comment on how it should hold up. And hold up it did; the RXF has seen literally zero love, aside from the occasional wipe down, and it feels as smooth and active as when it first saw action. There is zero discernible bushing play or binding, and aside from some cosmetic wear, you'd be able to convince us that the fork is brand new. Issues
- The lack of an external travel adjust feature doesn't bother us - we're generally not a fan of on-the-fly stroke adjustment as a crutch for a bike that's excessively slack - but changing the RXF's travel does require shipping it off to a service center to have the air spring cylinder tube or complete air spring assembly swapped out. The 140mm-travel fork can be set to 120mm and vice versa, but neither can be bumped up to 160mm due to the piston rod length on the damper side. However, the 160mm fork can be set to either 140mm or 120mm of travel with an air spring parts change. Yes, it's true that some other forks on the market require similar changes to alter their travel, but it'd be nice if it was a simple matter of moving some internal spacers around inside the RXF to get the job done.
The RXF's three-chamber air spring system also requires you to "reset the fork to its original length" if you've decided to lower the main air spring pressure. To do this, you simply hold the wheel down on the ground while pulling up on the handlebar ten times, or until you've fully exposed the correct amount of stanchion tube; 140mm for the 140mm-travel fork and so on. This isn't a big issue at all, but forget to do it and the fork won't fully extend, meaning that you won't have all of your travel available, which seems a bit hokey for a $1,150 USD product. Pinkbike's Take:
|No, the RXF 34 isn't exactly the mind-blowing paradigm shift of suspension performance that the Ohlins name might have some riders thinking it should be, and we wouldn't even say that it's better than a Pike or 34 in terms of outright performance, but it is certainly just as good. It's also heavier (about a full pound compared to a Factory Series Float 34 of the same travel and wheel size) and more expensive, which may or may not matter depending on what you value.|
What Ohlins has created is a fork that seems to be bombproof, with an extremely easy to tune damper and air spring that will work well for any type of rider. All that makes the RXF 34 a worthy alternative to a Pike or 34. - Mike Levy
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