MOST MANUFACTURERS EMPLOY ONE BASIC SUSPENSION SYSTEM TO HANDLE A WIDE VARIETY OF DUTIES—EVERYTHING FROM COMPETITIVE XC RACING TO AGGRESSIVE ALL-MOUNTAIN RIDING. THEY TAKE ONE DESIGN AND APPLY IT TO DIFFERENT BIKES BUILT FOR DIFFERENT PURPOSES BY MODIFYING THE REAR SHOCK AND LENGTH OF TRAVEL.
That’s one way to do it. But Felt engineers, accustomed to fine-tuning the designs of different bikes to meet precise performance goals, have taken an alternate approach; just as they wouldn’t accept using a road fork for a triathlon bike, they felt a lightweight XC racing bike has different suspension needs than a trail bike.
That’s why Felt has two different suspension systems—FAST for competitive XC and Equilink for marathon, trail or all-mountain riding. Each is designed to optimize the bike it’s paired with. FAST places great emphasis on ultra low weight, integration with a carbon rear triangle and pedaling efficiency. Equilink delivers a supple, active feel for rugged terrain plus incredible traction and braking control. Both are designed to make every off-road ride the best it can possibly be.
To meet the lofty standards of cross country racers on the Felt Ötztal X-Bionic Team and Team Kenda-Felt, engineers created an entirely new suspension system called Felt Active Stay Technology, or FAST. Offering 100 millimeters of smooth, predictable travel, FAST delivers unmatched performance in a lightweight, race-ready package.
FAST is about efficiency. It’s about soaking up the terrain and keeping your tires on the ground for the improved traction and handling needed in XC racing conditions.
The genius behind FAST is its simplicity. By creating a frame and suspension system that work in unison to achieve specific goals— namely, XC speed, control and efficiency—Felt engineers were able to pinpoint their efforts. FAST makes the most of the Felt’s considerable experience working with cutting-edge materials and construction techniques, and utilizes the design of the frame to optimize the bike’s overall suspension performance.
“FAST suspension technology embodies a light, stiff carbon fiber rear triangle assembly that doubles as a secondary spring assist to the rear suspension,” says Felt suspension engineer Mike Ducharme.
As Ducharme points out, one of the keys to FAST is the innovative rear stays. The carbon fiber seatstay and chainstay work together like a leaf spring, offering just enough flex to optimize rear suspension activity. The whole rear end is custom shaped and engineered to provide both a stable pedaling platform and a smooth trail feel. It helps keep your tires on the ground when climbing or pedaling through smaller stutter bumps—situations where suspension affects traction—and adds just enough compliance to reduce fatigue over long efforts such as marathon or 24-hour races.
FAST takes cues from the single-pivot suspension design that performance-minded XC riders favor because of light weight and reliability, and optimizes this tried-and-true system with a few new twists. It utilizes a set of carbon fiber stays that flex evenly throughout the suspension travel, providing performance characteristics that mimic much more complicated suspension systems—but without the extra weight and complexity.
“This design not only eliminates the need for an additional pivot in the assembly, but also acts to hold the suspension at the optimal ride/race geometry,” says Ducharme. “We were able to decrease the weight and increase efficiency by designing out unnecessary hardware and reducing unwanted suspension bob without sacrificing small bump compliance.”
The stays are designed to be neutral (in their natural shape) at the “sag point” because that’s where the bike typically rests under rider weight. The shock spring is supplemented by the design and material of the rear stay, which acts as a leaf spring, stiffening the latter part of the suspension travel. The slight additional spring provided by the carbon stay helps keep the suspension sitting at the proper sag point, which reduces small inputs from the rider that would cause unwanted bobbing from the suspension. This design eliminates the need for a mechanical lockout or an overly damped shock that requires extra force to be “opened.” The end result of all this: minimized bob without any harshness.
The construction and mechanical aspects of the FAST system reveal an obsessive eye for detail. Every last fitting has been scrutinized and selected for durability and weight reduction. The two main pivots feature sealed cartridge bearings for smooth performance, and there’s a unique “link axle” system for the shock links that reduces weight by using less steel hardware and a hard anodized axle for the shock links’ bearings to roll on. A “DU” bearing (similar to what
is found in shock eyelets) and titanium axle are used for the less- stressed seatstay pivot. Besides shedding precious grams, this pivot construction proved its durability in testing.
The result is incredible performance and extremely light weight – the recipes for racing success. FAST-equipped bikes have already taken major victories in at the highest level of the sport in both Europe and the U.S. Built specifically for the Edict Series, FAST is exactly what the XC racer, be it a short-track sprint fiend or an all-day marathon racer, demands in a bike.