ICT is a patented concept around which most Ellsworth frames are designed, allowing Ellsworth engineers to create an extremely efficient suspension design. ICT aligns the Instant Center on the chain torque line, so a rider’s pedaling motion won't activate the suspension. To understand why, you must first understand the following three items:
1) Instant Center (IC) -- The IC is the point at which the suspension is balanced at any specific point in the suspension cycle. At that instant, forces are neither working downward nor upward. As a suspension moves through its cycle, so does the IC. The IC is located at the intersection of two imaginary linkage lines: in the case of an Ellsworth suspension frame, the first line is drawn from the rear lower chain stay link through the BB pivot into infinity in front of the bike; the second line is drawn from the rear rocker pivot through the seat tube pivot out into infinity in front of the bike.
2) Chain Torque Line (CTL) -- The CTL is an imaginary line that follows the chain from the top of the middle cog on a cassette over the top of the middle chainring on the crank out into infinity in front of the bike. As the name suggests, this is the line at which the rider is placing torque on the chain.
3) The Intersection -- When the IC and CTL consistently intersect or track the cycle of the suspension, this is the Ellsworth patented zone known as ICT. Because these lines intersect, the chain torque has no effect on the suspension through its cycle. Thus, rider’s pedaling motion does not activate the suspension
While ICT is featured on the four-bar engineered Ellsworth frames: Truth, Epiphany, Moment and Rogue, the patented ATLAS design is featured on Ellsworth’s two single pivot bikes: Distance and Chaos. ATLAS uses a one-piece CNC machined swingarm and a single pivot, making the design both simple and affordable.
The secret to the ATLAS design is similar to that of ICT – it’s all about the chain torque line. Ellsworth places the forward pivot on the chain torque line, and the rear dropout well below it. This creates both minimal arcing of the axle path and maximizes the efficiency of the pedal stroke. And, the one-piece swingarm mated to the frame with sealed cartridge bearings provides the ultimate torsional stiffness. The end product is a smooth riding bike that won’t rob you of energy or your hard-earned cash.
Ideas like these are the product of passion – passion that fuels creativity – creativity that produces fantastic bikes. A mantra inside the Ellsworth catalog is, “…no expense will be spared in creating the lightest, most energy efficient bikes in the world, without limits, compromises … or equals
.” Arrogant? We don’t think so. Ride one and see.