A variable tooth sprockets uses a plurality of staggered tracking channels to position teeth. The variable tooth sprocket may comprise a first plate 3 having a plurality of tracking channels, a second plate having a plurality of tracking channels offset axially and radially with respect to the tracking channels of the first plate, and a plurality of teeth assemblies each having two offset pivots that locate respectively in tracking channels of the first and second plates. Each of the teeth assemblies may be under spring bias. An actuation cam 19 may cases each of the plurality of teeth to slide along their respective tracks so as to adjust the effective size of the variable tooth sprocket. The actuation cam may be formed in multiple pieces that are pivotally connected such that the cam is able to act upon a tooth assembly rotating that any radius.
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