By Gary J. Boulanger
Originally introduced in Europe as a 26-inch wheeled aluminum long-travel machine, the 2013 Felt Compulsion is coming to America, and relies on a refined patented Equilink suspension platform, adding 10mm of rear suspension adjustability to its base of 150mm of travel.
The front end is now made from UHC Performance carbon fiber (unidirectional carbon fiber mixed with impact-protective carbon fiber weave and impregnated resin) with full monocoque construction, where internal bladders minimize resin build-up to meet Felt’s design criteria of light weight, strength, and on-trail performance. The rear triangle is hydro formed 6061-T6 butted aluminum with triple butted seat and chain stays.
"Equilink separates drivetrain forces from the suspension," said Felt suspension engineer Mile Ducharme. "You don’t need a platform shock and you don’t need any kind of travel stabilizer. Our suspension just performs the way you want it to, all the time."
Equilink was developed and introduced by Felt in 2007 to address the negative affects of pedal bob and brake-jack. By isolating suspension and pedaling forces, neither the rear shock nor the drivetrain are affected by one another. According to Ducharme, this means the rear wheel remains planted on the trail, resulting in every pedal stroke being counted towards forward movement. Under power, chain tension tries to pull the lower link down while the upper link wants to pivot up. Since these two links are connected, the opposing forces cancel each other out. This means that while the bike is being pedaled, the suspension is left completely free to absorb impact.
According to Felt, Equilink holds its pedaling efficiency in any gear ratio, meaning the Compulsion will pedal with precision in the big chain ring, granny gear or any other cogs in a rear cassette.
Equilink gets its name from the dog bone-shaped bar that ties the upper and lower links together. This connection separates the opposing drivetrain and suspension action, providing an ‘equalized’ ride.
Little details and component spec
Sealed cartridge bearings are used in the Compulsion’s front triangle and in the main linkage for smooth operation and long life, while a DU-style bearing reduces weight in lower stress areas and protects the Equilink and dropout pivots. Acetyl thrust washers are also used to reduce unwanted friction and keep contaminants away from bearings, and overall frame weight was reduced via a new machining process, according to Ducharme.
The new Compulsion also features a Control Taper head tube and 142×12 rear thru-axle configuration for more rigidity and strength. The tapered head tube uses a new Semi-integrated headset design, making it compatible with certain angle-adjust headsets for customizable geometry. Adding a dropper seat post is made easier with Felt’s under-top-tube cable routing. All Compulsion frames feature ISCG 2003 tabs to accommodate chain guides.
All sizes (S, M, L, XL) use a 67.5-degree head angle and 73.5-degree seat angle, with 43.2cm chain stays. Product manager Andy Holmes also decided on a stable 40mm fork rake across the board for improved handling in aggressive, technical terrain.
Component spec includes a Shimano XT 2×10 drivetrain; Shimano XT hydraulic disc brakes; Fox 34 Float 26 CTD FIT Taper fork with 160mm travel and Kashima Coat; Fox Float CTD BV rear shock (set at 160mm); Crankbrothers Kronolog 125mm dropper seat post; Shimano XT Trail wheel set, with WTB Bronson tubeless ready tires.
The Felt Compulsion LT1 has a claimed weight of 28lbs., and will retail for $6,199. The Compulsion 1 frame, chock full of titanium fasteners, will retail for $3,099. Availability is September 2012.
The Compulsion LT3 shares the same front and rear triangle, but is assembled with a SRAM X-7/X-9 drivetrain, Rock Shox Lyric RC Solo Air fork, Rock Shox Monarch R rear shock (set at 160mm), Avid Elixir 5 hydraulic disc brakes, WTB Speed wheels and Bronson tires. Claimed weight is 32lbs, and retail will be $4,149.
An all-aluminum LT50 model with down-specced SRAM, Rock Shox, Avid and WTB components will be $2,899.
Stay tuned for more coverage of Felt’s 2013 line.