Double Crank from Famous Canadian

In the 1980's there was a famous Canadian champion named Jocelyn Lovell. He won a lot of races in North America and was probably going to race pro tour - until he got hit by a truck and could never ride again.

He is a nice man - I got to meet him in 1993 (my coach was his team mate).

He built his own bikes and experimented with different designs.

About the design - quoted from the source:

His bike..."had a freewheel sprocket on the normal right hand side and a fixed sprocket on the left hand side. As he moved away from the line he drove through the RH sprocket and the left hand fixed sprocket began to unscrew from the hub. It being of smaller diameter it turned at a slower rate than the RH sprocket and being on the "wrong side" of the hub it would naturally unscrew. After about seventy metres the LH fixed sprocket came up against the lockring and at that point drive was through the LH side and the RH sprocket freewheeled. The distance traveled before the higher gear engaged could be adjusted by setting the position of the lockring. The bigger the space between lockring and sprocket at the start the longer the distance before the higher gear engaged.
Jocelyn experimented for some considerable time to come up with a combination of sprockets and chainrings that would not only give two suitable ratios but that would need chain lengths that would be at the correct tension. He settled on a low gear of 42x13 (87.2") and a high gear of 53x15 (95.4")"

http://bicyclespecialties.blogspot.com/search?updated-min=2009-01-0...

This is from the father of a current Canadian Pro Tour rider