Shifter Boss Cover

thingiverse

http://problemsolversbike.com/products/shifter_boss_covers These protect your downtube shifter bosses, preventing most water from entering your frame and rusting the downtube. Save yourself money by not spending $10-20 on these; they're not worth it. Designed for 1.125" downtubes, a very common steel tubing size. My bike is from the 1980s, and this works fine; I imagine you could use a round file to get a better fit if needed. How I Designed This Based on Shimano downtube cable stops (http://www.wiggle.com/shimano-sti-pair-of-cable-stops/). Assembly & Materials The metal files are designed to be machined; I pulled the measurements directly from my Shimano boss covers. You'll likely have fit issues if you 3D print them; make sure to use the print files for 3D printing instead. I resized the features to compensate for shrinkage in the print process. Shimano cable stops come with buttonhead screws, measuring 10.28 mm long and 4.89 mm total outside thread diameter. Something around that size should work well; the buttonheads have a smooth transition with the rest of the cover. Use a round file to get a better fit if you need it.