My org had a spinathon over the weekend that went flawlessly - we had 6 one-hour rides over 7 hours with 10 minute breaks between each. Folks could ride as many sessions as they wanted ($20 for the first and $5 for each additional session). Most people rode 2-3 sessions and a few rode all day. It was pretty much a sellout. We raised a lot of money for our cyle room equipment, and it added some excitement to our cycle program. (Only problem: The rider in our logo has really bad form).