We know, we know, it sounds like click bait, but the reality is, we’ve ridden so many “Newest, best yet, totally redesigned” forks, that we weren’t really expecting that big of a difference between the Fox 38 fork and our trusty old Fox 36. In fact, even now while proofreading this, it’s hard trying to balance excitement for a product while trying to maintain that stoic, journalistic complex where we can’t totally love something without being slammed as corporate shills. But, after the first ride (and every ride after) on our new Pistachio Fox Factory 38 GRIP2 fork, it’s official, this thing rules. In fact it’s so good I had a call out to our contact at Fox asking if this fork got the, “special media treatment,” maybe I still am that skeptical, salty media hack afterall… Sean Estes chuckled in agreement and said, “Dude, we gave it a visual inspection and put it in the box. It’s just that good!” Ever since then I’ve been flogging that fork on the front of my Trek Rail 9.9 in an attempt to accelerate wear, inconsistencies or degradation of performance. I even ran it with about 10-PSI less than normal just to give me some extra hard bottom outs after launching that 50-lb ebike into orbit. It’s still soaking up the chatter and helping me charge hard months later.
THE LAB Fox has named the 38 as the hard-hitting, long travel enduro specialist, optimized for 160-180mm of travel. I requested the 160mm travel option to match up to my Trek Rail. The Fox 38 isn’t just two numbers better than a 36, it actually has a lot of cool new tech designed into it that makes it ride better than any fork I’ve been on yet.
QUICK CHECK Fox 38 160-180mm (27.5” or 29”)
New chassis with with floating axle and new arch shape to improve head tube clearance
Elliptical steerer tube
Lower leg bleeders with air/oil channels
GRIP2 damper with VVC (Variable Valve Control)
Larger 58mm crown diameter
Offsets: 37mm, 44mm and 51mm
Optional mud guard
Available in Factory, Performance Elite, Performance, and E-Bike models with GRIP2 and GRIP dampers
Weight: 2,289 g (our 160 mm x 29” model)
The 2021 Fox 38 chassis is a design and engineering masterpiece. It’s not just a beefed up 36, Fox created a new arch, crown, steerer tube and floating axle system to help take their product to the next level. Fox uses an elliptical steerer tube in the 38, which they say is noticeably stiffer and attempts to shave some weight from areas you don’t need it while reinforcing areas that do. Overall stiffness of the 38 is a notable jump from the 36, and the longer the fork is, the more you’ll notice it. Fox claims the fork is 38% stiffer torsionally, 31% stiffer laterally and 17% stiffer fore and aft. Something aggressive riders and ebikers will appreciate.
Beyond the larger diameter tubes, one of the most notable features of the new 38 is the rounded arch. After some Finite Element Analysis, Fox engineers realized that the best way to maximize frame stiffness while also clearing modern frame headtubes, was to create this burly, spherical arch over the tire.
While we could go on for days exploring the nuances of material application, reliefs and structural design used on the fork, we’ll let Fox’s website do the rest of the informing after just one more neat feature that we really like. Air bleeders and oil flow ports, how cool is that? At the back of the fork legs you’ll find bleed valves to help remove air from inside the fork legs, which can degrade performance. Running up and down from the bleeders are air/oil channels which serve two major functions: First is to increase air volume. As an air fork compresses, air volume decreases and causes the fork to get stiffer and more progressive in feel. These channels give the fork a little bit more air volume as the air flows passed the bushings into the space above, which means a more supple and coil-like feel throughout the full range of travel. A second benefit of the channels is oil flow. As that fast-moving air pushes up the channels, it also draws oil from the bath upwards and increases the lubrication of the foam rings and bushings.
Moving inside, the Fox 38 sports even more updates that make it a standout fork. First off, the new GRIP2 Damper is revised and gets Variable Valve Control (VVC) to improve tunability and feel on the trail. We asked Fox what exactly VVC does to the internals when you’re turning the knobs, here’s what they had to say. “Rather than putting preload onto a shim stack or close an orifice, we are changing the leverage ratio of the stack. By turning the dial we are moving the shims along a helical ridge that gains in height as it moves. This moves the focal point of where the shim begins to flex.”
Would you rather just focus on how it rides yet or keep feeling like you’re in science class? Let’s get to the good stuff.
Q & A with FOX
Can you explain what a floating axle is and why it’s important or beneficial to Fox’s fork design?
The floating axle eliminates the influence of hub width tolerance on the alignment of the fork legs. The non-brake side fork leg is free to move on the axle until the pinch bolt is torqued. This keeps the fork in an optimum low friction state after the wheel is installed.
Why do only certain forks offer the floating axle system?
This system adds a small amount of weight to the fork. XC and Trail forks are optimized for weight to meet the performance requirement of those bikes.
How did the idea for the elliptical steerer come about?
We were looking for a way to increase stiffness in the crown area without drastically increasing the weight of the fork. The Elliptical steer increase the amount of material in key areas in the steer while maintaining proper wall thickness in others.
What does the VVC actually do to the internals when you turn the GRIP2 dials?
Rather than putting preload onto a shim stack or close an orifice, we are changing the leverage ratio of the stack. By turning the dial we are moving the shims along a helical ridge that gains in height as it moves. This moves the focal point of where the shim begins to flex.
What is the difference between an eMTB model and a normal 38? Could a person buy a 38 this year and then next year when they see how much better ebikes are, put it on that? Haha
Difference will be in the Damper Tune. The E-bike damper tunes will have a lighter compression. We found that a vast majority of E-bikes are sitting down more when riding because they are under power. This allows for a more comfortable ride at the top end of the stroke. The E-bike damper is optimized for e-bikes. You can run a standard damper on an e-bike but might find that your ride experience would be more enjoyable on a properly tuned damper.
THE DIRT I’d been riding my Trek Rail 9.9 for months with the OE spec’d Rock Shox Lyrik and I couldn’t believe the upgrade it gave to my speed and confidence. I was able to get up and over the front end in soft turns, muscle the bike hard into catch ruts, and just pick up and hold on when it came time to send it into the chunk. It’s rare that I call friends to rave about products anymore, but I’m pretty sure I was speed dialing my top contacts on the way home telling them about this new fork I had.
The changes made to the EVOL air spring a certainly noted as the floating machined air sleeve offered much better sensitivity throughout the travel and kept the fork feeling like it had a coil in it. The suppleness and sensitivity are second to none. In fact, the fork honestly feels so good I couldn’t believe that Fox didn’t do some sort of Factory Race Team trickery to make it extra smooth. The only downside to the increased smoothness and supple feel is that I ran a little bit more air pressure and an extra volume reducer compared to other forks, specifically the Fox 36. Not a real complaint, rather just something to be aware of.
I found the 38 is more linear than other air forks I’ve ridden and while it was good for some things, very steep terrain that required heavy braking into three to five foot drops where you’d land on the brakes hard, meant I was regularly bottoming out the fork. After airing up a bit and adding that extra reducer I was able to improve that a bit without compromising my off the top feel too much.
I tried using the bleeders often during my testing and found that only about 50% of the time I pressed the buttons would I get that satisfying hiss. Nevertheless, it was a good reminder to check the system, inspect the seals and note the lubrication and cleanliness of the fork overall. Top notch.
The Wolf’s Last Word
We’ll try and wrap this up without going any more overboard than we already have. The new Fox 38 Factory fork is insane! It took my confidence, stability, and speed to another level once I installed it on my Trek Rail eMTB. The added stiffness of the chassis is welcomed on this platform as it allows aggressive riders to really lean up over the front of the bike and work. I felt like I could just twist the bars, yank up into rock gardens or lean back and plow over chunder without so much as a thought about where the bike would go.
What makes the new Fox 38 great is not just that it’s a stiffer version of the 36 that means less flex for aggressive enduro riders and ebikers, but that it also has so many enhancements to the damper, oil and air flow and compression/rebound circuit tuning that it makes you rethink what a fork should feel like. It offers the sensitivity and plushness of a coil with the on-trail tuning of an air damper in a stout and good-looking package. Our testers all hope to be seeing these forks spec’d on a lot more of our test bikes next year as they’ll certainly make our test rides even better.
Disclosure: Our team selects all of the products we review and do so with honesty and objectivity in mind. Some of the products we receive come directly from Competitive Cyclist, who also value our readers and have offered them a 15% discount on their first purchase by using LOAMWOLF15. Through this program we may also receive a small commission at no cost to you. Thanks for your support, TLW.
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