Drive mechanisms for human-powered machines

A bicycle including:

• a frame including means for releasably retaining a crankshaft or spindle;
• respective left and right crank arms adapted to have pedals or the like means associated therewith;
• and a power take-off means, the arrangement being such that each crank arm (or associated pedal) is adapted to be rotatable relative to said power take-off means to a limited extent.

A method which allows for the detection of the onset of a dead point in the operation of a human-powered machine, said machine including a crankshaft or spindle, respective left and right crank arms and a power take-off means, wherein one of the group consisting of said crank arms and said power take-off means is fixedly attached to said spindle, with the remaining members of said group being interconnected with said one member such that each is rotatable to a limited extent relative to said first member and each other.

An improved power transfer mechanism for use on a human-powered machine, said mechanism being adapted to be drivingly connected to a power take-off device of said machine, said machine being a bicycle having a crankshaft or spindle disposed within a frame and respective left side and right side crank arms each associated with a free end of said crankshaft, said mechanism including:

• a first adaptor means adapted, in use, to co-operate with said crankshaft or spindle;
• a spider or the like adapted to be associated with one of said crankshafts;
• and a second adaptor means adapted, in use, to co-operate with said one of said crank arms, the arrangement being such that said first and second adaptor means are each co-operable with said spider and said one of said crank arms and wherein said first and second adaptor means each include a plurality of dogs or lugs disposed around the periphery thereof.