Bike porn

anyone think of a logical reason to have the chainset at the front, I can't.

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Front crossover drive

A major, but little-appreciated advantage of crossover drive, is that you can use front drive. Front drive makes a lot of sense on a road tandem. In front drive, the drive chainwheels are on the front crankset, as shown here:

Front drive has some important advantages:

You can use any chainwheel-sprocket combination without chain angle problems, since the long front chain reduces the angles.

The drive chain lasts longer, because the wear is spread among more links, and so the sprockets also last longer.

Both riders can see and hear the front derailleur.

Stresses on the bottom brackets and the frame are lower than with rear crossover drive.

You can switch easily and quickly from the conventional rear crankset to a kidback by using a chain that runs diagonally from the kidback down to the front crankset, and lashing the conventional rear crankset to the frame so it does not turn. You do not have to remove the rear pedals when switching to the kidback.