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?

Don't put them on backwards. It's akin to trying to divide by zero.

Seriously, it makes little difference. The theory behind it is that the
grooves in the tire channel water away from the tire when riding on wet
roads, and if mounted the other direction water will be channeled the
other way, but I doubt if there's and evidence that this actually works.