We've given the original fat bike rear fender a facelift! The Mud Shovel 6. 5 Rear Fender was designed specifically for fat bikes - they're extra long and wide to block the muck, snow or sand you'll ride through on your next fat bike adventure. Made of heavy-duty polymer, the Mud Shovel 6. 5 Rear Fender is super lightweight but sturdy enough to take years of bad weather abuse. The rear fender mounts in seconds to your seatpost for easy on/off depending on riding and weather conditions.