Fox’s 2015 acquisition of Marzocchi was motivated partly by an ambition to create a more value-conscious range of forks. The results are the resurrected Bomber Z1 for enduro and the 58 for downhill. For 2019, these replace Fox’s 36 Performance and 40 Performance Elite forks for aftermarket sales.
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The architecture of the 58 is almost identical to a Fox 40. Its 40mm stanchions slide into lowers that look the same, save for a signature M-shaped brace and no air bleed system on the back.
The left leg contains identical internals too, in the form of Fox’s ‘EVOL’ (extra volume) air spring. It’s the volume of the negative spring that’s been increased, which contributes to a supple feel at the start of the stroke.
To resist bottom-out, volume spacers can be added. The Bomber 58 comes fitted with four clip-together 10cc spacers, but there’s space for seven.
It’s the right leg where things differ, with a ‘FIT GRIP’ damper in place of the ‘FIT4’ version in Fox’s 2018 range and the new ‘FIT GRIP2’ damper in the 2019 40 Factory.
FIT GRIP is still a closed system, like FIT4, which stops oil and air mixing as the fork goes through its travel. Any closed system must compensate for ever-changing oil volumes, and this fork does that by using an IFP (internal floating piston) controlled by a spring, rather than the bladder arrangement of FIT4, with looser seals to reduce friction.
Any oil that creeps past them is purged. There are external dials for low-speed compression (eight clicks) and rebound (22 clicks) adjustment, while high-speed damping can be customised internally.
I rode the 58 back-to-back with the 40 Performance Elite and noticed no difference, with the same characteristic trail-deadening feel and superb bump absorption and tracking.
The Bomber’s oversized chassis and 20x110mm axle with four clamp bolts keep things stiff and accurate, and the tunable bottom-out control ensures a smooth ramp-up when you push hard into bigger hits.
The 58 weighs just 80g more than the 40 too, at 2,750g (650b). Experts looking to fine tune ride feel may prefer the 2019 40 Factory with its independent, externally-adjustable high- and low-speed rebound and compression circuits, and improved valve systems. But for most, the 58’s combination of air pressure, progression and compression adjustment will allow an uncompromised, hassle-free set-up.
Marzocchi Bomber 58 fork specifications
- Stanchions: 40mm
- Damper: FIT GRIP
- Colours: Red, black