Topeak bike rack mounting system

thingiverse

NOTE - the latch bit has broken on me when printed as is. I'm going to try printing it on its side, that should greatly increase its strength. A little support and touch up work with a file will be required on the round surface. The sled to slide on the Topeak system, and the spring loaded latch to hold things in place. I have a Topeak rack and a bag, but have thought that a plastic ammo box would actually be exactly what I want on the rack. Always waterproof, plenty roomy and I can bolt a big taillight to it and it won't sag and change where it points. Also, Topeak bags are $50 to $100, ammo boxes are $5. There were a couple other sled designs online but none of them were perfect. Mainly they didn't have the little ramp that helps get things on the slide easily. Also I couldn't find anyone that had replicated the latch to hold things in place. I'm very happy with how this came out. Post-Printing Print all the bits. You may not need the backing if you are bolting to something very sturdy, but I was concerned that even with washers they might pull through the $5 ammo box I have. The latch spring needs to be a compression spring that fits close on a 6mm shaft. I found an expansion spring in the Harbor Freight spring kit #93323, stretched it to make it a compression spring and cut the length I wanted. To assemble the latch, put the spring over the shaft, compress it a bit, then fit the 2nd half of the latch holder and secure with #6x1/2" sheet metal screws. Attaching the sleds to your (whatever you are mounting) will be up to you, depending on what you're mounting. To attach the latch, slide the thing onto the rack, snap the latch over the end bar, then mark the position where the holes should be made in the thing. The latch is attached to the thing with #8 screws, whatever length you need, and #8 fender washers and #8 nylock nuts.