Fat Bike Fenders

thingiverse

Fat Bikes are a blast, but soggy bums are a no-go. Taking inspiration from the Fat Butt style fenders, I customized one for my lady's saddle with some clever tweaks. Tabs go under the bolts for added stability. A smiley cutout lets rainwater draining on top of the fender escape harmlessly. Brackets keep the fender pointing upwards (self-tapping into saddle plastic), and it leaves room for a tool bag attachment at a later time. It also frees up the clip-in gadget for other purposes, like stashing snacks or extra tools. However, mud still managed to splash onto me and the top of the fender, so I stuck my bike on a stand with the rear wheel submerged in a tray of water. This let me figure out that I needed something to catch the water spinning off from the quarter-way round tangent to the wheel. Rummaging through my garage, I found an old MTB mudguard that fit perfectly, but it only caught some of the spray – not enough for dry comfort even with my supposedly waterproof ski pants on. Back to the printer I went to build a custom extender that would hang the guard over the edge of the wheel. In testing, I got wet feet and muddy legs, but my bum remained dry enough to sit comfortably for a cup of tea before heading to the shower – mission accomplished! Now I can tackle mountains, streams, or whatever trails come my way without worrying about getting soaked. A stop at the cafe for cake is within reach! The fender was printed with flexible filament (85-98A), so you may need to adapt it to your bike's specifications. Here's the OpenSCAD file for you to modify and print – happy modifying! I also repurposed the first draft bum fender as a front fender, secured with zip ties. It catches even more mud and adds an extra layer of protection.