Fox 34 Step-Cast Review: a Svelte, Plush, and Sturdy MTB Fork

The highly tunable Fox 34 Step-Cast mountain bike fork caters not only to the XC racer, but also trail riders looking for a lightweight package.
The SC34 in Shiny Black finish. Photo: Matt Dunn.

Traditionally, Fox’s Step-Cast series forks have been closely associated with the XC discipline, but the 34SC variation brings beefier 34mm stanchions to the product line. This repositioning of the Step-Cast branding from race-day-only to everyday-trail-ready indicates Fox’s intention to target the “downcountry” audience for this bulked-up lightweight fork. The latest 34SC features a ground-up redesign with the aim of providing class-leading tunability, chassis stiffness, and strength.

Fox Factory 34 SC Specifications

  • Wheel size – 29”
  • Travel – 100mm, 120mm
  • Float EVOL air spring with lower leg bypass channels
  • Rake – 44/51mm
  • Axle – Kabolt 110
  • Upper Tube Finish – Kashima Coat
  • Rotor size – 160 direct post mount, up to 180mm compatible
  • Air Spring – FLOAT EVOL
  • Steerer – 1.5 Taper
  • Starting weight – 3.30 lbs/1496 g

In 2017, Fox introduced the Step-Cast (SC) offering as a 32mm stanchion-only platform. However, in 2019, they launched another version of the SC with larger 34mm-diameter stanchions designed to be more versatile for trail use. The Step-Cast platform is identifiable by the purposely shaped fork lowers that are designed to save weight.

The first generation of the 34 had removed material from the outside bottom section of the fork legs, while the new design removes material from the inside lower section, which moves the lowers closer to the wheel and disc brake. As a result, the new design is narrower side to side, while maintaining the same boost hub spacing at the axle. This design allows the brake rotor to fit nicely into the space cleared from the lower, but limits the rotor size to 180mm.

The newly designed round arch that was previously only available on the Fox 38 and 36 families of forks is now available on all 34 forks, including the SC, and is credited with improving stiffness. The weight of the new SC with all the changes is an impressive 3.3lbs before the steerer tube is cut. In addition, the new SC has lower leg bypass channels that alleviate resistance to reaching full travel, and the ability to tune the negative air spring with a volume spacer.

The 34SC fork is available in two different trim levels: Factory and Performance. The Factory model with FIT4 damper (tested) is priced at $1,019 and caters to a wide range of rider preferences. It offers two color options, two travel options, two fork offset options, and two FIT4 adjustment options, including a handlebar remote in addition to the fork-mounted dial. XC racers in particular will appreciate the option for a remote, but a remote was not included with my demo fork. I tested the Shiny Black, 120mm of travel, 44mm offset, Kabolt axle, and traditional fork mounted FIT4 dial version.

The Performance model with the GRIP damper, on the other hand, has limited options, available in only 120mm of travel, the choice of 15mm QR or Kabolt axle style, short offset only, and with no remote option. It also lacks the shiny paint and Kashima-coated stanchions, and the price is considerably less.

Fox 34 Step-Cast Fork Setup and FIT4 Settings

The fork was shipped with a star nut, tuning guide, three additional volume spacers, and a settings chart decal based on rider weight. Since this is the 120mm fork, the new negative air volume spacer was not included. The 100mm models come with a pre-installed volume spacer for a firmer feel, while the 120mm models do not come with a volume spacer for a plusher feel. Installing the negative air volume spacer is a more involved process (requiring removing the lowers from the uppers), so it’s best to get assistance from your local bike shop for those looking to add it.

Crown mounted FIT4 dial. Photo: Matt Dunn.

Since I have owned previous forks with the FIT4 damper, I was familiar with the three-position dial (open, medium, firm) and the “open mode adjust” to fine-tune the damper while in the open setting, which provides 22 clicks of adjustment. According to Fox, this feature is helpful in controlling performance under rider weight shifts, G-outs, and slow inputs. Rebound is adjusted through a traditional lower fork mounted dial that is advertised as having 10 available clicks, although the test fork I have seems to have 19. Fox’s recommended air pressure for a rider 120-150lb was between 58-68psi. I didn’t get out a tape measure for sag setting, but my assumption was 68psi would be the best place to start since I was on the very high side of the weight range.

On the trail

Mounted on my already zippy steel hardtail, the SC34 feels fast. Not only did it drop a half pound from my previous fork, during the first climb I noticed the audible “sssttt” from the air transferring from the bypass channels back into the lowers upon each compression rebound. The sound of speed had been built right into this fork, and looking down at the much narrower width it had a lightweight appearance too.

Test pilot profile height: 173cm (5’8″) weight: 67kg (147lbs) testing zone: Colorado, USA

The first ride was an approachable intermediate trail with some flow, some tech, and a bike park at the bottom of the hill for a few party laps afterward. From the start, the SC34 was supportive for climbing and riding flat areas, keeping high in its travel. It also delivered good small bump sensitivity, making it easy to climb rolling hills and some technical features. During some of the initial descents, the softer initial stoke ended quickly and I felt a resistance on medium to larger hits. The Fox 34 Step-Cast gave an absolute feel of responsiveness and support to push harder, allowing me to attack the rest of the descents with authority. When I got to the bottom it was clear that I didn’t get close to using all 120mm of travel.

Still short of full travel at 62psi. Photo: Matt Dunn.

Next I picked a more technical trail to ride four times consecutively since I knew the trail well enough to use it as a calibration testing ground. Despite having ridden this trail hundreds of times, it helped me evaluate the Fox 34SC’s feel on familiar features. For this trail I lowered the pressure to 62psi, and experienced a slightly softer mid-stroke, but difficulty reaching full travel. Here, less travel translates a much rougher ride especially considering I was on a hardtail.

I then dropped to 55psi on the next venture, which was clearly too low and caused the fork to dive too quickly, eliminating any mid-stroke support I had experienced before. It was especially apparent in loose corners making tire traction feel arbitrary. I realized that without proper air spring support, the available compression adjustments also wouldn’t work as intended. So, I decided to experiment with volume spacers to see if I could find a compromise.

Summary of First 5 ride settings:

PSISpacersResult
681Good initial stroke, firm mid-stroke, difficulty reaching full travel
621Good initial stroke and mid-stroke, difficulty reaching full travel
551Plush feel throughout, unsupportive and quick bottom out
503Good initial stroke and mid-support, difficulty reaching full travel
512Great feel throughout travel, supported through mid-stroke & bottom out. Full use of travel on larger hits.


The sweet spot

The SC34 performance made a dramatic improvement after experimenting with pressure settings and volume spacers. It came alive on all sections of the trail, especially blue trails with consistent chattery bumps. During high-speed descents, the fork has a Zen-like fluttery feel, reminiscent of longer travel forks with a much larger mid-range stoke. Thanks to the 19 clicks of available rebound, I was able to make small adjustments for each type of terrain.

With the pressure setting dialed, I set the rebound a few clicks further out from closed than Fox suggests, but with the larger range of clicks, both settings felt good. Even though they worked as intended, I never found the need to use either the medium or firm compression settings or the open-mode adjust. Most of my adjustments were made to get a softer feel from the SC34 and obviously adding compression only makes it stiffer. Further adjustments would be more useful to a competitive XC racer on a long climb or a heavier rider needing more early to mid stroke support.

As a final test, I chose to take the SC34 to the most smash-encouraging trail on the front range, Dakota Ridge. Dakota features constant varying angles of black diamond rock sections, and cleaning the entire ride can only be done with years of practice. With the same settings, the Fox 34 Step-Cast fork handled all of the double-black diamond features confidently and without any noticeable flex. It also kept that amazing small bump compliance, paired with a highly tunable rebound knob, which kept the front wheel predicable in punchy uphill tech.

Photo: Matt Dunn.

Pros and cons of the Fox 34 Step-Cast mountain bike fork

Pros

  • Class-leading low weight
  • Great adjustability to fine-tune to your riding style
  • Magical small-medium bump compliance and good bottom out resistance
  • Variety of options such as color, FIT4 adjustment, and fork offset

Cons

  • Long setup process to dial in the perfect settings, factory recommendations for PSI too high
  • No alternative damper option
  • Front rotor size limited to 180mm
  • Expensive

Bottom Line

The highly tunable Fox 34 Step-Cast fork caters not only to the XC racer, but the more aggressive rider looking for a lightweight package. Those that spend the time finding the perfect settings will be rewarded with a blissful fork feel.