Brit bikes and Sportsters all had the shifter in the right untill the DOT ruled that everyone had to match the jap bikes in '75. They could have just as well ruled the other way around and cost japan.inc a fortune in unneeded design costs (teach them to do everything backward) but it was a matter of who owns the most politicians.
Adapting is easy. There were very few electric start bikes made with the proper shifter location, so you just have to remember to shift with the tired/sore leg.
There was a certain logic behind the right side shifters. Because vertually all bikes of any consequence had all the more fragile stuff such as timing cases and oil pumps on the right side, experienced riders made an effort to put the bike down on the left when a crash was unavoidable. Since it is easier to get home with a damaged rear brake pedal than a ruined shifter, the old layout makes sense.
