Originally Posted by
cafzali
One word of caution here, though... while Garmins wheel use the wheel sensor, the "auto calculate" figures will almost always be off, sometimes to the tune of 10 percent of total distance. I always enter my wheel circumference manually (2096 mm for a 700x23 wheel) and never have issues.
I just ran into this today. Set the wheel size to "auto" at the beginning of the ride, took about 2.3 miles for Garmin to calculate ... it came up with 2060 mm. :O Unsurprisingly, instead of being 2% high, distance traveled was 1% low.