Jump to content



Recommended Posts

Fox Debuts New Downhill Fork - 40 RAD


by Richard Cunningham


Jun 1, 2012


Add to my Favorites


Kathy Sessler showed us some pics of the Santa Cruz Syndicate receiving and testing some prototype forks from Fox. From the pictures, we can say for sure that the new fork is a different platform. It's lowers are slender and the dropout extensions are visibly lightened. The Kashima-coated stanchions tubes are still 40-millimeters in diameter, but the fork looks far more compact than the previous 40. Behind the upper seal-heads are curious bosses with what appears to be fittings for threaded caps. There are a number of explanations for the unusual bosses: the simplest being a mounting position for a fender or a mud flap; or possibly a port for a remote spring preload adjustment (a feature common to road racing motos); with the most far-reaching guess being the integration of an electronic damping control.



Greg Minnaar inspects his proto Fox 40 RAD fork while Fox's Mark Fitzsimmons brings him up to speed on the features. Notice the bosses on the inside of the fork near the seal-heads and the super-slim sliders. Kathy Sessler photo




Mark and Greg inspect the new lowers and dropouts of the 40 RAD fork. The dropouts are visibly smaller, as is the entire slider chassis. Kathy Sessler photo



What Fox Racing Shox Has to Say


Fox Racing Shox would not comment on the new fork officially beyond saying that the name of the new fork is 40 RAD ( Racing Applications Development) and that it is truly an all new fork. Fox suspension guru Mark Fitzsimmons said that 90-percent of the 40 RAD fork's internals are retrofittable to previous 40 forks, which leads one to believe that 40 owners can upgrade to most of the 40 RAD's performance features.


About the fork, Mark Fitzsimmons said he would only speak in the broadest of terms: "Every part of the chassis is new. The goals were to design in some chassis compliance, keep the same stiffness, reduce unsprung weight, and to change the mass location. It does have a new damper that is designed to work with the new spring system."




(Clockwise) The original Fox 40 on left is huge-looking by comparison to the new 40 RAD prototype fork. Note the raised section at the seal head - just enough metal to house the bushing and wipers. The 40 RAD fork crown has a new profile as well and its underside is more squared off. The new dropouts retain the dual pinch-bolts of the original, but are smaller, lend us to believe that the sliders may be no longer made from cast magnesium. Kathy Sessler photo



About That New Spring System


Fox and Trek developed a hybrid air/coil spring system for the Fox 40 equipped Session 9.9 that incorporates a titanium coil spring which is augmented by compressed air (an innovation well proven by the Marzocchi 888 and 55 forks). Trek initially had exclusive use of the Fox hybrid spring for the Session, which employs a standard shock pump to tune the fork spring, but now it appears that the same or an upgraded version will now appear on the new 40 RAD fork. The advantages of a hybrid air/coil spring are that it spring rate can be fine tuned for any track or weather condition, and that one spring can handle a wider variety of rider weights. Of course, any percentage of the fork's coil-spring rate that can be augmented by compressed air will also save a considerable amount of weight.




PB photographer Colin Meagher got this closeup of the bosses behind the seal head in the pits at Val de Sole. Interesting that the center appears to be a button of sorts - Air bleed valves? Negative spring adjustment?. If you like mysteries, this is a good one.



Why the Skinny Sliders?


This is only guessing, but there is a possibility that Fox switched from magnesium lowers to aluminum. Aluminum is heavier than magnesium and in theory, magnesium has a better stiffness-to weight ratio, but magnesium can be quite porous, so it does not lend itself to thin castings. If Fox figured out a way to 3D-forge its fork lowers from aluminum in the same way that it produces its shock bodies (Squishing a billet of heated aluminum with such force that it gells and flows through the mold like plastic, producing a nearly finished part.), an aluminum slider could be created that would be thinner, stronger and lighter weight than its magnesium counterpart. While this is only guessing, Fox certainly has the intel and the resources to implement such a wild strategy.




Peaty and Josh Bryceland testing the prototype Fox 40 RAD forks in preparation for the Val de Sole World Cup DH. Kathy Sessler photo



When can I get a 40 RAD Fork?


Our bet is that the 40 RAD will be in production soon. While the new fork is still in prototype form, Fox Racing Shox has always put its customers needs ahead of its racing development strategy. Fox would not have developed the 40 RAD if it had no intentions of bringing it to market. Expect to see the fork OEM on DH bikes in mid 2013 and at your most lucky LBS about the same time. Until then, all eye will be on Santa Cruz, Trek, Scott Lapierre, GT and Morewood riders at Val di Sole this weekendto see how Fox's 40 RAD holds up under the heat of World Cup DH competition.

Edited by ............
Link to comment
Share on other sites

AND the 2013 ICD




posted by Tyler (Editor) - May 20, 2012 - 8pm EDT



If you recall from their recent 2013 product updates, Fox is taking a more integrated approach to front and rear suspension and has revised their damping characteristics to provide tunes optimized for climbing, “trail” and descending. The old 1-2-3 Pro Pedal settings are replaced across the range with CTD settings instead, with some models getting some additional adjustment within the Trail setting.

Look a little further back in time and you may recall their iRD (intelligent Ride Dynamics) intro at Interbike last fall with the electronic shock/fork set up app and pump. iRD is Fox’s categorization for electronic products “employing non-traditional solutions to help customers improve their ride experience.”

The first big product under iRD to hit production will be the Float iCD (intelligent Climb Descend) electronic remote switch. This is pretty much exactly what we speculated it would be after seeing it on Kabush’s Sea Otter winning Scott Spark 29er: it’s an electronic switch to toggle between Climb and Descend modes on the fork and, on full sussers, the shock.



The remote switch rotates around the bar and is super sleek…a far cry from their obnoxious mechanical remote. The downside to this ergonomic system is the loss of the middle Trail setting, which is arguably where most riders would spend the majority of their time. That said, it wouldn’t surprise any of us to see future iterations that include the trail settings because there are already three positions on the full suspension system’s switch (there were only two on Kabush’s bike that we could tell): Climb, Climb (rear only) and Descend. The half-full circle visible in the image above is the Climb-Rear Only setting and keeps the fork wide open while firming up the shock. By combining remotes for front and rear suspension, Float iCD offers quicker, easier and simultaneous changes with minimal hand movement. It might be a bit tough to use with the new Grip Shift, though. It can be mounted on the left or right.


What we didn’t know until now was why they were using the Shimano Di2 battery. Turns out it’s a genuine collaboration between the brands. Here’s the scoop, from Fox:

“Float iCD shares features with Shimano’s E-Tube electronic shifting technology. Float iCD uses Power-Line-Communication (PLC) that allows data and power to flow along a single wire. This permits minimal wiring and ease of set-up, using only three wires for full suspension bikes and two wires for front suspension bikes. The system also has a PC interface option that allows customization of the remote switch function and provides access to diagnostic tools, switch operation counting and firmware updates.”


The Climb mode has firm low speed compression and the Descend mode opens it up to soak up larger hits and drops. The exact settings can be programmed with software intended for dealers, but it’ll be for sale to consumers, too.


Fox says the expected battery life is around 2-1/2 months, which means you’ll only need to charge it about six times per year just to be on the safe side. Actuation speed is very quick, just 0.25 seconds to switch modes at the fork and 0.45 seconds for the shock.

UPDATE 1: Confirmed, the red knob remains as external rebound adjustment, same as their regular shocks. Actuation is via small servo motors that twist the adjustments in the same manner you’d rotate the compression knob.


Initially, the system will only be available on the Float iCD 100 or 120 forks and Float iCD shock. Here are the details, from Fox:

  • Fork: Internal actuator unit, Factory series with FIT damper and Kashima-coated upper tubes, 100mm or 120mm, 26” or 29” wheel, and 9mm or 15QR axle options.
  • Shock: External actuator unit, Factory series with Kashima-coated body and air sleeve, 6.5×1.5” to 7.875×2.0” sizes, and standard or large eyelet air volume options.
  • Remote Switch: Right or left mounting option, two or three position rotary switch, non-contact operation and integrated battery low feature.


The Full Suspension System includes fork, shock, battery, battery bracket and remote switch with three cables linking the system together. Weight is as low as 1860g (4.10 lbs) for a 100mm tapered fork with 9mm QR dropouts and a 6.5×1.5 shock w/o hardware. US retail is set at $1,999.

The Front Suspension System includes fork, battery, battery bracket and remote switch with two cables. Weight is as low as 1555g (3.43 lbs). US retail is set at $1,499. International pricing is not set yet.

UPDATE 2: Compared to standard fork and shock, Fox says there’s a 70g weight penalty for the electronics added to just the fork, and 140g added on a full suspension setup. Fox’s marketing manager says that’s for the remote, wiring and servo contraptions and the battery. The Ultegra Di2 battery and mounting harness come in around 74g and 35g respectively on our scale, but this comparison is to the standard FIT fork and Float shock with the mechanical remote.

UPDATE 3: A tapered steerer fork with 9mm QR dropouts is offered in Europe, not in the US, meaning the lightest weight system in the US would be about 80g heavier, but that includes the front thru-axle, so it’s almost a wash.

Availability is set at September, 2012. We have a few questions in to Fox’s marketing guys and will update this post as soon as we hear back with more details.

Now, about the bike. I spoke with Adrian Montgomery, Scott’s marketing guy, and he said due to the timing of this release, you probably won’t see it spec’d on 2013 model bikes as most brands are showing those to dealers and distributors now and spec has long been finalized. For big brands at least. On team bikes, including this one, he simply gave them the go-ahead to drill the frame for battery mounts and wiring ports because, well, the frame can handle it and the pros don’t care about voiding their warranty. We should mention neither they nor we recommend you do this to your own bike. Look for 2014 models to have this system integrated a little more cleanly than the color-matched tape hiding wires.

Edited by ............
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Settings My Forum Content My Followed Content Forum Settings Ad Messages My Ads My Favourites My Saved Alerts My Pay Deals Help Logout