Riding the 2021 Fox 40 Fork
I was recently asked to review the new Fox 40 for model year 2021. Initially I declined because I only had a 29er downhill bike, and I'd be after a Fox 49 to review. Except I'd be wrong, because there is no longer a Fox 49 for 2021. To stay consistent with the rest of the fork naming in the Fox lineup, the new 2021 Fox 40 has options for both 27.5" and 29" wheels, and the 49 name has been dropped. After this news I was rather excited to try out the new Fox 40 ... with a 29er wheel!
Maybe it's just me, but I feel like the Fox 49 was just released. How much could have possibly changed to warrant this review of the new Fox 40? As it turns out, quite a lot. Fox has made updates to the air spring, the damper and the lowers. So pretty much everything.
Intended Use; Downhill
Wheel size; 27.5" or 29"
Spring; EVOL Air Spring
Damper; Grip 2 with VVC
External Adjustments; High and Low Speed Compression, High and Low Speed Rebound
Travel; 203 mm
Offset; 48 mm (27.5" wheel) / 52 mm (29" wheel)
Axle; Floating 20 mm Thru-Axle x 110 Boost
Colours; Black, Orange or Battleship
Starting Weight; 2816 grams
MSRP; $2,310 CDN or $1,749 USD
Grip 2 VVC
The damper in the latest Fox forks is based on the fantastic Grip 2. VVC is Fox's latest improvement to the Grip 2 high-speed circuits, which allow for external fine-tuning of said circuits. Fox claims that GRIP2 VVC achieves with the twist of a knob what typically requires the time consuming and complicated task of completely disassembling and reassembling the fork.This video gives some good additional info on how and why Fox has implemented VVC. Externally adjustable low-speed compression and rebound, each have 16 clicks while externally adjustable high-speed compression and rebound twist to 8 clicks apiece.
EVOL Air Spring
EVOL technology increases negative air spring volume, which Fox claims will optimize small bump sensitivity. Fox says this is because EVOL’s linear spring curve delivers plushness off the top, extra mid-stroke support, and more tunable bottom-out progression.
Lower Leg Improvements:
The arches on all the new Fox forks have been shifted forward. The purpose is to clear the growing head tubes on many modern bikes when the fork is at bottom out. The Canyon Sender I'm riding is a good example as it has 16 mm of reach adjustment built into the head tube. With the reach adjustment in the shortest setting there is quite a lot of headtube in front of the steerer tube. Some have commented that the arches on the new Fox forks are ugly. But when mounted up I don't mind the look and I understand why Fox has made the change. Beyond the arch jutting forward, Fox claims they've been able to optimize the shape of the arch to ensure maximum stiffness with the smallest amount of material.
The floating axle found in both the new 36 an 38 has also been implemented in the Fox 40 allowing the fork's wheel mounting surface to precisely match the front hub flange spacing. Fox claims this helps prevent any bending and side loading of the fork lowers, which should reduce unwanted friction between the upper and lower fork legs. If used properly the floating axle should provide smoother suspension movement throughout the fork’s travel, improving sensitivity and overall ride quality.
Fox has revised the lower leg bleeders to allow for easy atmospheric pressure equalization. Pressure build-up in the lower legs will add preload to the suspension, and make achieving full travel more difficult. Being able to regularly vent the lowers should ensure the best fork performance and small bump sensitivity.
In order for the air to get to the air bleeders, Fox has added lower leg channels in the new Fox 40, which also increase the air volume in the lower leg. This increase in volume reduces pressure build in the lowers at bottom out, which allows for more control of the air spring ramp by using tokens in the air spring. Another benefit of these channels is that the lower leg bath oil is more easily circulated to the upper reaches of the lower legs, which should reduce stiction.
I've had the fork a few months now, and been able to ride the Fox 40 through a wide variety of trails and conditions. I've played around with a variety of settings, and settled on the following:
My 2021 Fox Fork Setup:
Air Pressure: 87 psi
High-speed compression: 4 clicks out (out of 8 clicks)
Low-speed compression: 7 clicks out (out of 16 clicks)
High-speed rebound: 5 clicks out (out of 8 clicks)
Low-speed rebound: 5 clicks out (out of 16 clicks)
On my first few rides I found the Fox 40 a bit harsh. I was moving around on settings, but it just never seemed to adsorb the high speed bumps like the Fox 49 I rode on the V10 last year. After the first few rides however, I felt like the fork performance improved. It could be that I got the settings to a place where I really liked them, but I feel like there was a short break in period on the new Fox 40.
Performance-wise, I expected the new Grip2 VVC damper to be a significant step forward but I didn't notice a massive improvement over the standard Grip2. Again, that's not a bad thing, I thought the Grip2 damper in the Fox 49 was pretty much perfect, and the Grip2 VVC is just as good. I can confirm that the Grip2 VVC produces a lot less compression damping with the adjusters closed than the Grip2 damper. However the Grip2 VVC and Grip2 at my desired settings feel very similar in damper profile. Furthermore I still had ample adjustment range on the Grip2 VVC, so I could have run more compression damping if I wanted. It looks like Fox has significantly narrowed down the adjustment range on the high speed compression circuit with VVC. So while I think the Grip2 VVC is just as good as the Grip2, folks looking for an ultra-firm high-speed compression tune may run into limitations with the Grip2 VVC damper. As for the external adjustments, all seemed to make a noticeable and predictable change. Ultimately I was able to get the Fox 40 to perform exactly to my taste. Good low speed support, with relatively open high speed circuits to build traction and save my hands.
Now that it's broken in and setup correctly I love how the Fox 40 performs on trail. The fork provides great support through low-speed events, building superb traction through braking and cornering. The firm support and stiff chassis do a great job of communicating what's happening with the front tire through to the rider. All the small changes to address friction add up to make a structurally stiff chassis, but with no stiction or binding anywhere in the travel. With the air bleeders regularly equalized, the Fox 40 always feels buttery and frictionless. The best bit is that you can have all that support, but without any harshness through the travel. The high speed compression circuit is incredibly effective at adsorbing rough braking bumps and bomb holes. This is heavenly for someone like myself (an office worker with soft hands) where I can have the support and control, but with less arm pump. There were a couple situations where I jumped into a section and saw I was heading for a nasty looking hole going way too fast. I braced for impact, making that cringey face, body ready for the horrific impac, hands clinging to the bars, waiting for an almighty clap. Then, OMNOM, the 40 would just miraculously eat the nasty hole. From what should have been a horror impact event through the fork, the 40 would transmit only a minimal amount of force.
Another trait I like about the Fox 40 is how well it performs over a wide variety of terrain. Some forks need a different setup whether on a steep gnarly trail, or a faster low angle one. With the 40, once I got my settings right I barely touched them. Regardless of the type of trail the Fox 40 provided excellent traction and support. I have however noticed the Grip2 dampers are a little temperature sensitive. All suspension will run a bit slower when it's cold out, but I feel I notice it more with the Grip2 dampers than on some other forks. This is easy to rectify by removing a click or two of damping depending on how cold it is. I personally email myself my suspension settings when I'm happy with the setup, and whenever I make any changes. This way I know what to change back when the temperatures warm up.
After a couple months riding the new 2021 Fox 40 I can say this an excellent fork. It's a top-shelf product, that isn't cheap. Thankfully the price of admission means there is little to complain about. The air spring is smooth, and can be tuned to ramp to your taste. The new Grip2 VVC damper is good as well, unless you're looking for loads of high speed compression damping. The fork felt buttery and frictionless over the test period. Through a wide range of terrain the Fox 40 proved stiff and precise, providing excellent support, but also suppleness over square edges and fast brake bumps.
My only critiques of the Fox 40 are that it isn't a big step forward performance-wise over the already excellent Fox 49, and the damper may need adjusting when it's cold. On the plus side I like the new air bleeders and like how the new Mud Guard interfaces with the fork. I also like the Battleship colour, especially on this test mule. So much drooling. I really enjoyed my time on the Fox 40, and while it's expensive, I think it's hard to beat.
Age - 37
Height - 183 cm / 6'
Weight - 86 kg / 190 lbs
Ape Index - 1.055 / +10 cm
Inseam - 81 cm / 32"
Race Enduro and Downhill
Bar Width - 800 mm
Preferred Reach - 500 - 520 cm (but this is stack and head angle dependent)