On 4/6/2021 9:05 AM, Mark cleary wrote:
I notice that the Conti GP 5000 I have and even the old GP II 4's, have a direction of rotation on the sidewall. Now mind you I so far have put the tires with the proper rotational direction, but what happens if you don't. My guess is if you put them on the opposite way then does the bike go backwards when I start pedaling? Do the tires wear out different, or possible be off balance. But seriously what is the catch?
Deacon Mark

My guess is that it has to do with the "rain grooves" on the tread, to
help them "pump" water away from the center. Doubt the direction makes
much difference, though *reversing* direction after the tire has been
used a lot may increase the chance of tread delamination (wild guess on
my part).

On knobbies, it's a different story. Shaped knobs bite into dirt/gravel
differently depending on their direction.

Mark J.