We often pre-register for rides we want to do. Usually get a discount, plus t-shirt, meal, motivation, etc... Makes planning much easier for those running the event. But we have had several recent rides were the weather was terrible, so we looked at the registration as a donation and skipped the ride. Sort of depends on the ride, but I an see it being a problem. No good answer, just seems to be the trend for people to not pre-register.