Xtrac shows seamless gearchange alternative to dual clutch transmission

After two years secret development in motorsport competition, Xtrac unveiled an important new driveline technology this week in the form of an Instantaneous Gearchange System (IGS). It does exactly the same thing a dual clutch transmission achieves with less weight, cost, and complexity. The secret to Xtrac IGS is the integration of a ratchet and pawl mechanism between each gear hub and the main shaft so that two consecutive gear ratios can be selected and engaged simultaneously, but with only one set of gears driving.

via gizmag.com