It’s good fun ‘winding’ the numbers up in the comparison tool to find larger improvements, but the paddles still need to be useable!
Having seen the improved ‘values’ by increasing the paddle crank (rake), it was found when testing that the tip angle needed to be reduced (from it’s newly increased angle), to allow the paddle to enter the water satisfactorily at the catch. Interestingly the tip angle we settled on (of around minus 11 degrees) is similar to some ‘pre-wing’ wooden flatwater blades. (Typically wing blades are nearer minus 20-22 degrees).
While Increasing the crank angle improves efficiency, it also increases the ‘out of balance forces’ of the paddle. The paddle shaft connects onto the back of a Physic blade to reduce these ‘out of balance forces’ to a little lower than typical wing paddles. (To eliminate them completely you would need to add an Ivan Lawler ‘Featherweight’ to the paddle shaft).
There’s no arguing with the science, bigger blades are more efficient. But while blades the size of dustbin lids would in themselves be more efficient, there are a number of reasons why this might not be a good idea, (their unwieldiness and dire impact on the paddlers cadence for starters!) Hence only small increases in blade size (perhaps around 10%) might be considered practical, which would be combined with a slightly shorter shaft to avoid the ‘load’ experienced by the paddler changing. (The paddler still needs to be able to operate at the cadence which works best for them).