The clearance is in reference to the calipers clearing the inside of the wheel. The space is very tight but it works great and the more narrow tires work better in the snow too. I have not checked to see the difference in the speedometer but I do have a Garmin 350 that gives some feedback about actual speed which I will check next time I am out.
I did get new sensors put on the wheels when I ordered them from Tire Rack, it seemed the easiest to get the whole package delivered and not have to worry about anything more than taking off the old wheels and putting on the new ones. When you consider mounting tires on rims costs nearly $100 each time, it quickly pays for getting the whole setup. The roundels on the wheels are actually just stickers that go over the ASA logos and they were included with the wheels.
So far so good...I'll give a report at the end of the season to let everyone know how they worked in some real winter weather conditions.
