Fox’s brand new halo suspension fork is the inverted Podium. It’s expensive, it’s sexy, and it’s claimed to offer the performance of a downhill fork in an enduro package. It’s no secret Fox has been developing an upside-down fork, with ‘spy’ shots of top racers testing it, and even a static Fox RAD prototype on display at Sea Otter. Finally we can reveal the details that make this quite a special prospect for anyone looking for that ‘unfair advantage’, as Fox puts it. To read my first ride review of the Fox Podium click here.

The Podium is not Fox’s first inverted MTB fork, but it is the first one to make it into production.

Fox Podium fork need to know

• Inverted enduro fork with travel options at 150mm, 160mm, and 170mm
• 47mm upper tubes and 36mm lower tubes
• 20mm steel through axle
• Claimed fore-aft stiffness close a Fox 40
• Claimed torsional stiffness close to a 160mm travel Fox 36
• 32% more bushing overlap than a Fox 38
• Glidecore air-spring reduces binding
• Custom-tuned Grip X2 damper with firmer compression and lighter rebound
• Weight is 2,810g for 170mm travel
• Priced at £2,199 / $1,999.99 USD / $2,679 CAD / €2,399 / $3,349 AUD

So those are the headline features, but the real motivation behind the Podium fork was simple: to build a fork that became more effective on the roughest tracks. And an upside down design is inherently optimised for that task, thanks to better bushing overlap, fore-aft stiffness, seal/bushing lubrication, and less unsprung weight than a conventional fork. The downsides being that it’s harder to achieve similar levels of torsional stiffness without increasing weight, and that inverted forks are not as easy to live with day-to-day when it comes to tasks like removing and installing the wheel, or fitting a mudguard.

It’s a shame you only get to see those Kashima lowers from behind.

Low-friction mission

The Fox engineers really went all-out to reduce friction in the Podium and make the best suspension fork they could. Particularly running friction, or the type of stick-slip, inconsistent friction that occurs when the fork is loaded up and binding occurs at seals and bushings. It’s the kind of friction that is impossible to tune the damper for, and results in harshness and transmission of bump forces to the rider, creating a loss of control and fatigue. Fox has already made a great stab at reducing this with its floating Glidecore air-spring found on the new 36, but the Podium chassis offers even more advantages to the engineers. Such as the fact that the bushing overlap on the Podium is 32% wider than on the 38, and 7% wider than the 40. This helps keep the lowers sliding inline with the upper tubes, reducing binding, particularly in a fore-aft plane, where Fox claims the single-crown Podium is close the stiffness of a dual-crown 40. Here, in situations like heavy downhill braking, flat landings, and braking bumps, the Podium can work more freely than a conventional fork.

Three travel options are available (150mm-170mm), with a strong focus on enduro riding and racing.

Works better the harder you push

The upside-down design works more effectively the further into the travel it gets, as the distance from the axle to the lower bushing gets shorter and leverage reduces. Throw in the fact that the upside down fork has marginally less unsprung weight than a conventional fork, and the seals are constantly lubricated through the joys of gravity, and you’ve got a seriously slippery fork for the damper to control.

Tech highlights include a generatively-designed crown and pressure-balanced custom Grip X2 damper.

Custom pressure-balanced Grip X2 damper

That damper is the latest Grip X2 unit with the oversized base valve and increased shim count for better tuning fidelity. The Grip X2 is also pressure balanced, which helps with reaction times and direction changes from compression to rebound. It’s actually a custom tune compared to the 38, with more compression damping to compensate for the reduced friction, and less rebound damping thanks to the lighter unsprung mass.

Super-wide bushings and the clever Glidecore air spring spearhead the fight against friction.

Glidecore piston

On the air-spring side there’s a Glidecore piston, with rubber bushings that allow the piston to glide smoothly under load. It’s upside down, so the air valve is at the dropout, but removing the top cap with an HG cassette tool lets you add or remove the 5cc volume spacers. To change the travel between 150mm, 160mm, or 170mm you’ll need a new air spring.

A 20mm steel axle keeps torsional flex in check, while carbon guards protect the lower legs.

Torsional stiffness of a Fox 36

I mentioned the Achilles heel of inverted forks being torsional flex. Where making them stiff enough basically means adding weight. And the Podium does suffer a little in both these regards. Torsional stiffness on the bench of the 170mm Podium is equivalent to a 160mm travel 36 according to Fox. But the weight penalty is about 300g over a 38 Factory Grip X2.

Multiple axles designs and materials were tested, but the final version wasn’t actually the stiffest on the table.

Not as easy to live with as a conventional fork

Then there’s convenience. The Podium uses a custom steel 20mm through-axle with four pinch bolts. So you’ll either need a front wheel with a convertible hub, or a new front wheel to run in the Podium. Removing said wheel is more of a faff, with four bolts to tighten in sequence, and dropouts that don’t stay aligned when you remove the wheel. There are carbon lower leg guards to protect the Kashima coating and hold the brake hose, but you can remove these and run a bracket for the hose instead.

No shortage of mud clearance, and there’s a mudguard coming.

How much?! Fox Podium pricing

Don’t expect this kind of tech to come cheap. The new Fox Podium fork is a spendy bit of kit, costing £2,199 in the UK. Add to that the cost of a new front wheel and you’re looking at around £2.5k all-in. Will that hold people back from buying one? My bet is that the kind of rider seduced by the Podium isn’t too concerned about the price.