1.2 centimeters?!

I personally wouldn't go riding until it passes. If you absolutely must... stay close in town and be sure to have your charged cellphone with you and someone available to pick you up in case you get another attack of renal colic while on the bike.

Also try your best to save the stone so that they can analyze it's chemical content. There are 4 primary types of kidney stones, each caused by different dietary habits and health conditions. You'll want to know what kind of stone it was so that you know what kind of diet to maintain in the future.