FOX
40

Setting proper sag ensures your 40 is able to use its 203 mm travel effectively. We suggest 15% to 20% sag for aggressive downhill riding, or 20% to 25% for a softer, more forgiving feel. Check sag while standing on the pedals in your aggressive riding position, leaning gently against a wall for support.

While the FOX 40 can be physically mounted to various types of mountain bike frames, most non-downhill frames are not designed for the unique stresses caused by a dual crown DH fork and will not only negatively impact the bike's geometry but also compromise the structural integrity of the frame. Mounting a 40 on anything other than an approved downhill mountain bike frame will void the warranty and could injury or death. Contact your frame manufacturer to confirm compatibility.

The 20mm x 110mm Boost floating axle eliminates unintended friction between the upper and lower fork legs by allowing the lower legs to float slightly, accommodating minor variation in hub widths. The result is incredibly smooth suspension movement throughout the entire 203 mm range of travel.

FOX’s lower leg bleeders equalize atmospheric pressure at the press of a button. Pressure builds up in the lower legs and eventually degrades small-bump sensitivity. Similarly, internal bypass channels in the lowers increase lower leg air volume and keep bath oil circulating to lubricate foam rings and keep your fork running smooth.

The 4-way adjustable GRIP X2 Damper offers unmatched tunability for high-speed compression (HSC) and rebound (HSR), as well as low-speed compression (LSC) and low-speed rebound (LSR). We recommend starting with the base settings which can be found on a decal on every FOX fork, then bracketing from there based on personal preferences.