Two months ago I built a 3D printer, which pretty much means I’m gonna find reasons to print shit. Yeah, I suppose it wasn’t the best idea to replace your missing coffee lid with a leaky block of non-FDA approved motorcycle fairing, but at least those windshield wipers I fixed are still holding strong. Maybe… *maybe* there were a few times when I made questionable material choices, but if you want to solve problems then you need to accept a little risk here and there. Look, I’m not being stupid about it and I’m not doing anything real dangerous. It’s just middle-aged dangerous. Nagging-injury dangerous. Meet-your-insurance-deductible dangerous. Which brings me to this.
Early version fit check.
The red plate in the middle is a bracket that I made from ABS for a recent winter bikepacking trip in the Black Hills. It attaches to the rear dropout of a medium Surly Ogre using the fender and rack mounts, and clamps to the seat stay for additional support. There are mounts for a Salsa Anything cage in a position that leaves reasonable room for wheel clearance without causing heel strike annoyances. I made this because I was growing concerned over the amount of gear I was placing on the front end, and this bracket would allow me to shift more of it to the back. It went through a few revisions before I was comfortable enough to load it, but it held up well over a couple of days on snowy, rocky singletrack. On one side I packed my stove, pot and accessories (minus fuel) and on the other I kept my spare layers in a drybag.
This project is a work in progress, so I’ll be keeping track of the important notes and milestones here.
January 10th, 2016
Initial version tested during a 2+ day bikepacking trip on the Centennial trail in the Black Hills. In the end, all was shiny. I had no issues other than a crack in one bracket along the lower mounting hole due to over-tightening. The next step will be to remove additional material/weight and increase functionality/adaptability. For some stupid reason I keep forgetting to add strap clearance. New materials will be tested against ABS versions, notably CarbonFil.
The current weight is around 150g per bracket. The shell thickness is 1.5mm top and bottom, and 1mm on the sides. One bracket was printed with 30% infill and the other was 40%, but I didn’t notice any real difference between the two on the trail. I had to press in some M5 nuts and do a small amount of grinding due to interference with the rear brake, but otherwise I used it as is.
Rear side of one of the brackets I used on the ride. I had to grind a little to add clearance for the brake rotor and a mounting bolt.
On the trail.
I missed my turn about a half mile back. I rode another mile before I realized it.