Because it is all set up as my winter commuter and switching it back and forth every week last year was a giant, annoying, pain in the butt. Also, cross takes a lot out of my life. Dedicating all day every Sunday (half of my very precious weekend) to drive out to some far-flung suburb & spend all day there, plus practicing and training, plus I suck and am way out of shape right now and have fallen back into smoking (!!!) lately due to serious life suck, plus I just don't want to.