I have yet to buy a bike before I ride it first or at least a version of it. There are lots of online bike retailers though so I assume people do it all the time?
I agree that a test ride around the parking lot, or even on the road, in itself is not enough to make an informed decision. It's just the final step before purchase. By that time, you should have a good idea of the brand, model, component group, size, etc. that you are interested in.I havn't found a spin "around the parking lot" any more informative than the sizing information posted on most websites.
I like GM's marketing plan where you have 60 days to decide wheather you like their car or not. For me a 20 minute test drive isn't enough to decide on a major purchase. It takes me 20 minutes to figure out the radio and climate controls.