The first prototype frame was a high single-pivot with a shock linkage to control the leverage ratio. It featured a large 22-tooth idler pulley to reduce friction, 100% anti-rise, and 100% anti-squat at sag in every gear. It rode well, but suspension performance was held back by the high unsprung weight of the swingarm and linkage and too high of anti-rise. It was also very complicated to construct.
Prototype 2 was aimed at decreasing unsprung weight for better suspension performance and lowering anti-rise for more active braking. It decreased unsprung weight by a whopping 600 grams! It also raised anti-squat slightly for a firmer pedaling feel. The leverage curve was straightened as much as possible for easier shock tuning. It now featured a straight 78° uninterrupted seat tube and a 64° head angle.
Prototype 3 took everything learned from Prototype 2 and improved it further. The bottom bracket was lowered 5mm and head angle reduced to 63.5°. These changes were designed to play better around 30% sag instead of the 35% sag of prototypes 1 and 2. Anti-rise was slightly lowered, and torsional stiffness was improved with small construction changes. It now featured a 24-tooth idler pulley for even less drivetrain friction.