Back when enduro riders used regular tubes instead of moose inserts I used to always here reports and claims of pro riders changing tubes in something like 5 minutes. I've also heard of current ISDE riders like Jeff Fredette changing both tires in 10-15 minutes. Whats even more amazing is they would do these changes to a muddy bike laid on its side by a trail, and they would use short, fanny pack size tire irons. To me this is even more amazing than how fast they ride. In my clean, warm shop, useing long tire irons and wd-40 I couldn't hope to change a tire in less than 30 minutes. I'm inclined to believe this but it is sort of hard to do. Has anybody ever witnessed or done something like this?