Inside the Prototype FOX RAD 34 Fork - All Hype or True Performance?

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While the ultra-exclusive FOX RAD 34 fork may appear the same as FOX's production forks, what's inside creates a drastically different ride. Developed and ridden as part of FOX's Racing Applications Development (RAD) Program, the fork's internals and performance tricks are currently being evaluated for future implementation into consumer level forks. Prior to 2013, the RAD program focused on cross-country and downhill racing, but the enduro boom provided a new setting to advance their product line. With guys like Jared Graves, Dan Atherton, Martin Maes, Nico Lau, Lars Sternberg, Greg Minnaar and Tracy Moseley at the helm, you know that products are seeing some serious abuse in the field. Even though we may not all ride like them, we all benefit from the feedback the Pros provide and the features and performance their speeds demand.

When offered the opportunity to try out a RAD level fork, of course we said yes. Is the fork that only some of the best Enduro racers get to ride as good as it gets, or is it just a bit of hype? That's what we set out to determine…

Prototype RAD 34 Fork Highlights

- Prototype RAD CTD damper
- New Kashima coated damper rods
- New seals throughout to reduce dynamic friction
- New 20 weight gold oil for lubrication
- New bushing size
- New 15mm Kabolt thru-axle
- Stock 2014 air spring, chassis, and Kashima coated 34mm stanchions
- TALAS travel adjust system
- Measured weight for 27.5-inch 160mm fork: 4.67-pounds (2,118 grams)

While a good portion of our test fork was nearly identical to a stock 2014 FOX Talas 34, the damper, seals, lubrication oil, bushings, and axle have all seen changes that may or may not make it to production. Most changes were made in the name of improved damping and control while lowering friction.

Of particular interest is the prototype RAD CTD damper, which includes a mid-valve. While not revolutionary and often used in motocross forks, the mid-valve provides added low-speed compression damping and the amount of oil that flows through it plays a role in how high the fork rides. This allowed FOX to lighten the damping in the main piston valve stack without leading to fork dive. High-speed impacts are met with more a progressive damping tune than before. FOX has also played around with the point at which the negative spring signs off at in order to get closer to that coveted coil-feel in an air-sprung package. While we’re sure there are more secrets to be revealed later, the combination creates a fork that is insanely supple off the top but provides great support through the rest of its travel. Our test fork included a simple to use CTD (Climb-Trail-Descend) lever, but it’s likely that we’ll see the return of independent low and high-speed compression adjustments from FOX in the future, at least on some models - a change requested by their Pros and high-end recreational riders alike.

Similar to the new FOX FLOAT 40, the RAD fork uses Kashima coated damper rods, 20 weight gold lubrication oil, and new seals throughout to reduce dynamic friction. The bushings have also been opened ever so slightly to further improve the smoothness of the fork.

Curious to see if there was a big change weight wise we threw it on the shop scale. Coming in at 4.67-pounds with the axle and a star nut, it’s not far off the claimed 4.4-pounds for the stock 2014 TALAS 34.



Testing the RAD 34

Sedona, Arizona’s varied and rocky terrain played host to our one-day test of the RAD 34. We started with a 20-mile loop including four of the area’s best descents followed by several runs down the rough and rowdy Brewer Trail - enough terrain to really get a feel for what the fork has to offer. Just before the sun went down, we switched back to a stock 2014 FOX TALAS 34. The video in the slideshow included several side-by-side comparisons of the FOX RAD 34 to a stock 2014 FOX Talas 34 CTD fork. Could you see the differences?

Having ridden the trail multiple times on the RAD 34, swapping to the 2014 TALAS 34 and riding the trail again allowed us to immediately feel out the changes. The result really surprised us.

Aboard the RAD 34 we quickly built up a very high level of confidence through the roughest bits. Lap times decreased every run as a result. The fork had the best initial sensitivity of any we’ve ever tried, and it was able to recover more quickly and smoothly than any other as well. This translated to far less feedback in the hands, and in turn less arm pump during extended runs. We could enter rocky sections at speed and maintain control with ease, off camber or otherwise, as the front wheel seemed glued to the ground and unfazed by quick changes in the terrain. At no point did we feel like the front end was diving too deeply into its travel, even under big compressions or off drops. The ride was much like the very well-regarded Rock Shox Pike, controlled yet supple, but even more so. Regardless of the trail conditions we could point the fork in any direction we pleased and go there without surprise.

Swapping the fork with a stock 2014 TALAS 34, that elevated sense of confidence went out the window momentarily while we readjusted. The difference between how and when the damping is applied is drastic. While riding in the firmest Trail mode (something we don’t often do on 2014 CTD products) the fork has such a distinct platform feel that the action seems relatively notchy, requiring you to push through it to get the best feel. On the trail this translates to less control, less traction and far more feedback to the hands. Trying to maintain the same speeds ridden on the RAD 34, we found ourselves pin-balling down a trail we were familiar with. Switching to Descend mode the 2014 TALAS performed in a much more controlled manner, but lacked the superb initial sensitivity of the RAD 34. The 2014 TALAS is no slouch, especially when compared to the 2013 offerings, but there’s still room for improvement. The RAD fork provided more control and more traction at all times, allowing us to brake later and charge harder.

Watching the video, the relative suppleness of the fork is readily apparent, as is its ability to recover between successive hits. You can even get a sense of the extra steering needed to correct movements on the 2014 TALAS.

That’s all well and good, but what it does it mean for the everyday rider? When FOX introduced the 2014 range of CTD products we began seeing improvements gained from the RAD program - namely increased damping and progression from the 2013 lineup. The next round of changes inspired by the program look to be even better, and that’s something to be excited about. The control and feel offered by the RAD fork is second to none. This testing experience says a lot about what happens when suspension is tuned for true performance over that showroom/platform feel.

Of course, the tradeoff between performance and durability has yet to be seen. With the pros receiving constant service at races to keep their gear in tip-top shape, can something like this be produced in a way that is reliable in the long term? Or will the end user be required to perform maintenance on a more regular basis? Would you be willing to service your suspension more often in exchange for the best ride? There’s always a compromise to be made in the suspension game. If FOX can balance the components and tradeoffs in a way that yields this high level of performance with low maintenance, they’ll have produced one of the RADdest forks of all time. We’ll have to wait and see.

Keep an eye on what FOX is up to at www.ridefox.com

Photos by Brandon Turman, Sven Martin, Duncan Philpott, Dave Trumpore and Thomas Dietze
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