Formula Selva C Fork

Formula's Selva C is their coil sprung, 160mm travel 29er fork. The 27.5 fork is also available with 170mm.

Before digging in, fresh cherries from my tree were consumed.

There was a beer close by for safety…

The lowers were quickly dropped to get started.

With only eight rides on the Selva C, the oil was like new, not that you could tell once it drained into Ben's catch pan.

The ends of the shafts are keyed, making it easier to pull the lowers. Formula's forks don't rely on the pressure fit of others and there's no hammer needed to bash the shafts free from the lowers. The damper side…

And the spring side. The keys also make it easy to put the fork together. They slot into the lowers and prevent spinning while tightening things down.

The foam rings from the new seal package were soaked in Formula FX oil. I'm told it's similar to a 20wt oil.

With the lowers off, the damper lockout lever was removed so Formula's special tool – provided with the fork – can access the keyed interface on the top cap.

The same is done on the spring side. I've had no issues removing the spring top cap with the Formula tool and it provides a more secure feeling connection than a regular socket.

Spring removed. The heat shrink pieces have migrated toward the centre of the spring from the recommended 60mm from each end. Also, note the white nylon pieces just beyond the spring. These sit between the preload adjuster and the spring, with the open cylinder capping around the top of the spring.

With the upper spring assembly removed, Ben gets into the spiral retaining ring.

The spiral retaining ring is used instead of a more common standard clip with an opening that's squeezed together. These are said to provide improved retention thanks to the 360 degrees of contact.

Spring side disassembled (with a couple external adjusters from the damper side).

The negative spring. It sits at the bottom of the stanchion, with the spring on top.

The spiral retaining ring (right) holds everything in the stanchion. A wave washer (left) sits against the bottom of the negative spring and a washer in between.

The damper utilizes a rubber bladder, similar to what's found on some other forks. It allows the displacement of oil as the shaft compresses with minimal friction.

This little seal head houses some interesting parts that make the damper function a bit differently to others.

The top of the seal head with the low-speed rebound needle visible at the top of the shaft.

The seal head and its internals. The pieces to the right, particularly the bushing next to the seal head housing, and their rounded edges. It doesn't seem like much but the square edges of a typical bushing in this part of the damper easily bind when a side load is added. Formula use rounded edges to allow unimpeded movement while the fork experiences lateral loads. This is noticeable on the trail, with the fork remaining very active and minimizing feedback when the front wheel is being hit from angles.

The components of the lower damper. The shaft moves through the seal head and its bushings and seals with rounded edges, and on the right is the rebound circuit.

The high-speed rebound circuit. As with most suspension brands, this is set by Formula. On the right is the shim stack and on the left of the piston is the check valve.

During a rebound cycle, the spring pushes the oil against the piston but on compression, it releases and allows oil to flow freely past the piston. Without it, every rebound adjustment would also affect behaviour during compression.

The low speed rebound needle inside the damper shaft (what you're adjusting with the external knob at the bottom of the fork).

The high-speed rebound circuit back on the damper shaft.

Formula use a unique method to tune the compression damper of their forks. Their CTS (Compression Tuning System) cartridge provides riders with seven different compression settings by changing the cartridge. Each cartridge can be fine-tuned externally with a blue dial at the top of the fork.

A series of holes in the cartridge valves provide the different compression characteristics. My Selva C came with gold and blue CTS cartridges. The gold valve has more, smaller holes, while the blue has bigger holes, but less of them, and a relief (on the right side of the blue valve pictured) that changes how the oil flows during a compression. The valve on the right is a special super-light option that allows the easiest oil flow.

Ben shows the shim against the bottom of the blue valve. The rounded edge of the nut beneath allows the shim to flex when oil is forced through the circuit.

Formula's Selva forks come with a lockout, too. When flipping the lever on and off it lowers or raises this needle in the compression damper. The chamfered edges create a strong seal (there's a more natural stop for two chamfered edges as well).

Bleeding the damper is easily done from the top of the fork. It doesn't need to be taken apart to do so, either.

Before the lowers are slid back on, the foam rings are removed from their fresh soak and place in the fork.

After putting the internals back together and sliding the lowers on a little, a syringe is used to fill each lower with 15cc of Formula FX oil.

This isn't very different to other forks but is always a satisfying part of tearing down a fork. It's almost ready to ride.

A quick clean to the bottom of each lower leg after pressing the lowers completely on, engaging them with the keyed part of the shafts.

Formula use a copper washer and o-ring to seal the lowers, rather than the crush washers found on some other forks.

Tighten down the damper side…

Then the spring side.

Give the fork a wipe to clean any oil from it and it's ready to mount back on the bike.