Ohlins brings DH tech to enduro mountain bikes w/ new RXF36 fork, TTX Air shock

Ohlins has been quietly preparing their own suspension products in house, building on the lessons learned making forks and shocks for team riders and OEM brands like Specialized. Now, they’re rolling out an updated trail/enduro mountain bike suspension fork and all-new air shock aimed at the most popular riding styles. The 2019 RFX36 uses the damping cartridge tech from their dual-crown downhill fork, downsizing and retuning it for shorter travel and better small bump compliance. And the all-new TTX Air shock borrows the deeper bushing and seal overlap and damping tech of their TTX coil spring shock and puts it in a lighter, more easily tuned package.

2019 Ohlins RFX36 Fork

While the Ohlins RFX36 fork has been available aftermarket for a while, and been generally well received, they found that smaller, lighter riders weren’t getting the most out of it. For some, the compression could be over-damped, which limited its ability to mute small bumps and sometimes took too much force to begin moving. And the rebound was under-damped to the point where it was coming back too quickly for lightweight riders.

To solve these, they looked at the damping, the chassis, and the seals and bushings. Starting with the fixed points, they switched SKF wipers and used a different grease to reduce initial stiction. The chassis is new, necessary to increase tire clearance (it’s big, see spec list below for numbers), and the crown is now stiffer, too.

They also updated the seals and bushings on the damping pistons to reduce friction and stiction there. Technically, it’s an all new damping piston called TTX18, which refers to the 18mm piston. Internally, they tweaked the shape and layout of the seals and shaft to reduce friction under bending and twisting forces, too. Overall, it adds up to a claimed 50% reduction in breakaway force and overall lower friction throughout the travel.

On the air spring, they increased the negative chamber’s size to balance out small bump compliance. They say this also improved mid-stroke support, and the system uses Ohlin’s three-chamber air spring. Meaning, there’s a secondary positive air spring that you fill from the bottom that kicks in during the last part of your travel to control ramp rate. Volume spacers can be added to either air chamber (or both) to fine tune the whole system, but the dual positive chamber allows you to make trailside tweaks.

Opt for the air spring and you can get up to 180mm of travel. Or, choose a coil spring version and get up to 170mm of travel, and they say you’ll actually get a full 170mm regardless of spring rate or preload. The high strength steel springs themselves are new and about 10% lighter, and come with higher spring rate options.

The nice thing about all of this? The air spring parts, damping cartridge, bushings, and seals are all retrofittable to existing RFX36 forks, and the price for a complete new fork is $1,125 (€1,040).

2019 Ohlins RFX36 Spec List:

Travel: 120-180mm (air) or 130-170mm (coil)
15 clicks low speed rebound
15 clicks low speed compression
3 mode high speed compression + climb mode
36mm upper tube diameter
Offset 27.5 (46 mm and 38 mm)
Offset 29 (51 mm and 44 mm)
Max tire sizes 29×2.8 / 27.5 x 2.8 / 27.5+ x 3.2
Mudguard mounts
Weight: TBA

2019 Ohlins DH Race Fork Updates

Their DH fork gets several of the same internal, seal and bushing updates, and matches the increased tire clearance of the enduro fork…mostly. The max 29er tire size is 2.6, not 2.8, otherwise it’s the same. The 38mm stanchions get a tougher surface treatment that penetrates deeper into the alloy to improve durability and smoothness. The RFX36 gets this same new treatment, also.

The crown was updated to be stiffer, and now comes in different offset options. Price is $1,600 (€1,462) for the complete fork, and $350 (€319) for the new crowns. Drop in damper cartridges for the Fox 40 and Rockshox Boxxer are $749 (€684).

2019 Ohlins TTX Air rear shock

Using the same damping tech from their TTX22M coil shock, the new Ohlins TTX Air shock swaps the coil for a dual air chamber, which presented new challenges. For any air spring system to work, you need to contain the air (obviously), which means tight seals. But tight seals create friction. The trick is keeping the air in while still allowing things to slide smoothly. The other cause of friction, wear and potential air leakage on a rear shock are the side loads imposed by the frames. And some impose more than others depending on how stiff the linkages, pivots and frame members are.

These aren’t new problems, and every brand has their own way of solving them. For Ohlins, this meant a combination of low friction Trelleborg seals, a proprietary oil and grease combination, longer bushing and seal overlap, and better surface treatments. They say the combination allows for 100,000 cycles before air leakage can be detected.

Depending on the setup and size, up to 10 volume spacers can be used to tune the spring rate. Their standard setup is with half the stack, letting you tune in either direction by adding or removing them.