Just to clarify so someone doesn't misinterpret the tire statement:
* Less air does make the tire shorter and the tire stays in the beams longer, BUT, it's shorter because less air creates a longer "flat" area at the bottom that the starting line lights "see", so it blocks the beams longer. More air "lifts" the tire and makes it rounder, so there is less tire length that the lights see and results in slightly quicker reaction times.
* When it comes to the actual "manufactured" tire height, at the same air pressure, a shorter 26" tire will produce slightly faster RT's than a 27" tire. If you're in the ballpark, you can then fine tune RT's based on the previous info with air pressure.
