Surly 29" x 3" Presta Valve Tube You've got all set up on your awesome new 29+ trail machine and POP! Flat tire. . It's a bummer, but don't let a popped tube be the end of your ride. This Surly 29+ tube is just what you need to get your Krampus (or any 29" x 3" wheeled bike) back on the trail! Size 29" x 3"Prest Vlave 32-40mm | Surly | 29 X 3 Presta Valve Tube Surly | 29 X 3 Presta Valve Tube