Formula has been developing a modest lineup of single-crown suspension forks for over three years, and the moment has finally arrived for the renowned brake maker to release them into the marketplace. We got our hands on the ThirtyFive 29 - and as those familiar with Formula's handiwork would expect, it is beautifully constructed - with anodized aluminum "touch-me" lever and dial adjustments, a forged aluminum crown and big, 35-millimeter stanchion tubes. Inside, the fork is packed with user-friendly features like snap-on travel-adjust shims.a damping cartridge that can be removed while the fork is still on the bike, and an air-spring system that can be tuned for a more progressive spring rate simply by adding oil. ThirtyFive forks can be ordered with either 140 or 100 millimeters of travel, and to fit either 27.5 or 29-inch wheels. Color options are white or black, and the weight of our 29er test fork with an uncut steerer tube was 1760 grams. MSRP is $1250 USD. Can a Brake Maker Build Suspension Forks?I was visiting the Formula factory in Prato, Italy, where founder Andrea Becocci showed me a prototype suspension fork. Initially, I was skeptical that the project would achieve success. Formula is well equipped to engineer and build a fork. Its manufacturing facility is absolutely state-of-the-art and it is staffed with some of the sharpest minds that I have come across in the bike industry. That said, the marketplace for single-crown, mid-travel suspension forks is stuffed to the tipping point with offerings from recognized brands - which raises the question: "What motivated Formula to take on such a risky endeavor?" The answer may be simple. The people at Formula ride mountain bikes and motos, they thought they could do as good or better of a job as the top suspension makers were doing, and they were excited to give it a go. Formula is a family owned company. They have no shareholders to answer to, so they have the freedom to make any product they want, and to dedicate whatever resources are necessary to get it right. The ThirtyFive is beautiful, contemporary, expensive and Italian - there will be customers. - RC
• Purpose: Trail/AM
• 35mm hard-anodized 7000 aluminum stanchion tubes
• Magnesium lowers with post-type brake mounts
• Easily removable damping cartridge with bladder-type expansion circuit to prevent air emulsion.
• External adjustments: low-speed rebound, low-speed compression, lockout and lockout threshold
• Internal adjustments: air-spring ending-stroke rate, clip-on travel-adjustment spacers
• Air spring with "Dual Coil" two-stage coil-type negative spring
• Low friction polymeric bushings
• Tapered steerer and 15mm through-axle only
• Optional hydraulic remote lockout
• Axle-to-crown: 540mm (measured)
• Dropout offset: 44mm
• Travel: 29-inch, 120mm to 140mm
• Colors: black or white
• Weight: 1700g
• MSRP: $1250 USD
• Contact: Formula USA
Gold is lockout, blue is compression and an Allen key in the
center of the rubber disc sets the lockout's blow-off threshold. Low-speed rebound damping is in the usual spot. It is effective. Post-mounts are set for 150mm rotors. The pull-out quick-
release handle is simply a lever for screwing the axle into the fork.
Single-crown suspension forks have reached the pinnacle of their evolution, so most designs share the same basic features. Formula's ThirtyFive fork follows Fox and Rockshox, with one-piece cast-magnesium lowers, a 15-millimeter through-axle, and a hollow, forged-aluminum crown fixed to an aluminum steerer tube. Post-type caliper mounts fit six-inch rotors directly, and inside the sliders, low-friction seals and polymeric composite bushings minimize sliding friction. Formula offers only a tapered steerer tube, which is OK by us. The stanchions are beefy, 35 millimeter diameter tubes, made from hard-anodized, 7000 series aluminum alloy. Formula outsources some of the fork's components to Asia, and then mates all the bits together in its factory in Italy. Construction and finish of the ThirtyFive fork are beautifully done - but maybe you have to be Italian to fall in love with the graphics.
Damping: Formula's cartridge damper features an expansion bladder that prevents the suspension fluid from being contaminated or emulsified by air bubbles - a key performance feature shared by both the RockShox Pike and Fox Factory FIT forks - and the cartridge can be removed for service without taking the fork from the bike. High-speed rebound and compression forces are controlled by conventional shim stacks inside the cartridge, which is serviceable, but presently, Formula recommends that customers leave that job to authorized dealers and Formula tech stations.
External controls: Formula puts three important controls on the right fork crown and one below the slider. Beautifully made from color-anodized, machined aluminum, they include low-speed compression and low-speed rebound damping, lockout and lockout threshold. The blue compression dial is up top and the red rebound adjuster, below the right-side dropout. A gold lever beside the compression dial switches the fork from lockout to full open, while a 2.5-millimeter Allen key accesses the center of the black, rubberized dial to adjust the blow-off threshold for the lockout - which is a very useful tuning feature that can be used to create a very firm pedaling platform to match the shock's stiffest option. The entire upper cap can be rotated to arrange the adjustment features to suit the rider's preference.
Dual-coil negative spring: Rather than employ a lighter weight air-type negative spring, Formula chose to use a coil-type to provide a longer, smoother transition from stasis, to the full support of the air spring. A second coil-type negative spring doubles as a top-out cushion. At present, there are no plans to offer stiffer or softer negative springs, because Formula discovered that for short to medium stroke forks, one spring could handle the full range of spring pressures that the ThirtyFive is expected to see in the field.
End-stroke spring rate: Formula sets the default oil level in the air-spring chamber at 10cc's. Raising or lowering the oil level determines the end-stroke spring rate. The factory has yet to produce tuning recommendations for this, although Formula USA says that they are reconstructing their website to include a comprehensive tuning section. Formula includes suspension fluid with the fork for this purpose.
Internal travel adjustment: The ThirtyFive's travel can be reduced from 140 to 120 millimeters by pulling out the spring-piston shaft and clipping on a 10, 15 or 20-millimeter plastic spacer. Our kit had one of each size and Formula has easy to understand instructions in its owner's manual PDF to switch the spacers.
Hydraulic remote lockout option: Formula offers a handlebar
remote lever that replaces the low-speed compression and threshold dials on the fork crown. It makes sense that the lockout is hydraulically actuated, as Formula has all the necessary pieces to make a reliable system in house. The remote is reported to add 90 grams to the fork.Tool-less through-axle:
Conventional threads fix the hollow, 15-millimeter aluminum axle to the right dropout and a tapered collet ensures that the axle secures the left side. The quick-release lever functions only as a wrench handle. It is hinged to a 4-millimeter hex shaft that tightens the axle. The handle can be removed completely and stowed, or indexed and closed in a desirable position. Formula's 15mm through-axle can be tightened with a 4mm Allen wrench or with the faux quick release handle that hinges on an Allen hex and snaps into the axle. The tapered collet on the left-side makes a direct, more secure connection with the dropout.
Honestly, setting up the ThirtyFive fork was as easy as it gets. We followed the air pressure suggestions in the Formula PDF file, which resulted in 20-percent sag at 60psi. We then adjusted the low-speed rebound six clicks out, to the point where we could just sense it, but waited to fool with the low-speed compression dial until we had some trail time to assess the bike's ride height. We used a Niner R.I.P. Nine as a test sled, and the 140-millimeter-stroke Formula ThirtyFive fork replaced a 130-millimeter RockShox Revelation Solo-Air model. Remarkably, even with the Formula's larger, 35-millimeter stanchion tubes, the two forks weighed the same (1740 grams with cut steerers).
so there was no weight penalty in exchange for the extra travel, as well as the sigificant boost in stiffness and steering precision. When we hit the dirt, Formula's default compression setting (six clicks out) seemed about right for fast-paced technical trail work - with enough firmness to keep the fork from diving under braking and when descending steeps, while providing enough cushion to keep the front tire smoothly tracking the surface.Steering:
Formula's ThirtyFive 29 fork has an axle-to-crown length that is 25 millimeters taller than the two most popular 140-millimeter options, which slackened the Niner's head angle by a half-degree. The result was a welcome increase in straight-line stability, at the expense of a slight tendency for the front end to wander while climbing steep trails. Other than that one potential negative, the ThirtyFive performed beautifully in the bends, with a light feel at the handlebar and dependable tracking over just about any surface. Drop a foot and push the bike hard over embedded rocks and hardened ruts, and the fork will drive around the corner without a wiggle. The upgrade in torsional stiffness was such that we could sense exactly what the front tire was doing. The ThirtyFive communicates well without feeling harsh.Bump control:
We did much of the test work aboard the Niner on fast-paced, enduro style trails, packed with natural rock features and intermediate jumps. Set up to ride slightly higher than the shock, the ThirtyFive's low-speed small-bump compliance was on the rough side of comfortable, but that was partly a function of our chosen low-speed compression setting. The fork has almost no static friction, so with the spring pressure set softer and the low-speed compression backed off to a more XC/trail tune, the feel is very supple at singletrack speeds. The firmer tune that we preferred, however, was better suited for charging descents and bashing through the many rock sections in the zone. Through mid-stroke to full travel was where test riders were most impressed with the damping performance. It was progressive enough to take us beyond our comfort levels, while retaining enough bump control in reserve to cover significant square-edge impacts, bad landings or frantic line decisions.Damping notes:
By accident or by design, the damping feels speed sensitive in both compression and rebound. We are referring to damper-shaft speeds, and this is more noticeable during the rebound stroke. We originally set the rebound resistance higher than necessary after discovering that the cartridge's internal valve stack's rebound function had a very broad range. We found that we could back off the low-speed rebound dial until it seemed that there was no rebound force in the parking lot push test and the fork would still feel smooth and in control over chatter. Low-speed compression was effective to the point where, when we found the sweet spot, one or two clicks would alter the fork's ride height by a centimeter.Lockout function:
The curved, gold-anodized lever toggles the fork's lockout function, which was used mostly when we were climbing paved roads. Like most forks with a lockout option, there is an internal blow-off valve that prevents the cartridge from ballooning, or worse, should a rider launch a personal-best huck to flat with the damper's oil flow blocked off. The spring loaded blow-off valve can be tuned with a 2.5-millimeter Allen key, and when it is backed off most of the way, creates the feel of an ultra-firm pedaling platform, while allowing the fork to function in a reduced, but useful manner. We are confident that this tune is not recommended by Formula.....but.Issues:
Formula's fork rates high on the like scale, so there were very few nit-picks from test riders. The first is a nuisance, not a performance downgrade: a persistent hiss from the rebound damping circuit that occurs when the fork cycles to and past mid-stroke. We used to call it AMP-Physemia - after the more-pronounced hiss that AMP suspension forks and shocks made with every bump in the trail. The second is the fork's 44-millimeter offfset is perfect for 29er with head angles near 69 degrees, but a longer offset would be more optimal for the slacker-is-better crowd. That said, it's not a deal breaker. We doubt that any rider would notice the difference between Formula's 44, RockShox's 46, and Fox's 47 millimeter offsets. Most riders, though, could sense the jump from 44 to the 51-millimeter offset that many contemporary long-stroke 29er sliders are switching to. Pinkbike's Take
| Formula's ThirtyFive fork arrives on the scene at the moment when it is most needed. Its larger-diameter stanchion tubes and robust lowers provide the extra rigidity that big-wheel all-mountain bikes desperately need, it is one of the lightest in its class, and its damping and steering performance are a match for the rapidly growing crowd who are choosing 29ers to battle in the more aggressive riding arenas that were once the exclusive domain of the 26er. Formula's 140-millimeter-travel ThirtyFive fork easily out-performs the RockShox Revelation it replaced, and while its stiffness and steering are a match, its small-bump compliance falls short of the Pike, which is its nearest competitor. The ThirtyFive 29 puts Formula into the performance suspension game. If the Italian manufacturer can follow through with solid customer service and produce a 160-millimeter sibling, they will soon be mixing it up with the big boys - and that's a game Formula knows how to play. - RC|