I was reminded the other day of the vulnerability of a belt drive; what felt like a nail embedding in my tire turned out to be milk carton cardboard getting pulled under/between the rear sprocket and drive belt. I pulled over and removed it pretty easily, but I've been wondering whether a guard is possible or available in some way. Even a reverse mounting of the upper belt guard would be suitable.
Here are my latest attempt to make a belt guard for the bottom side of the belt going into the wheel sprocket.
I have already printed the swing arm attachement, but the bottom needed some adjustments. I hope the version i put here will be final:
Thoughts behind it are:
1: To be able to mount it, i will need two parts:
1a) One for attaching to the swing arm, and
1b) One for deflecting pebbles and debris
2: The upper part is attached to the lower part of the swing arm, using 2 hose clamps which seems to secure it very well.
3: The upper part allowes for vertical adjustment of the casing by moving side to side before clamping.
4: The upper part fixes the angle but allowes for some horisontal adjustment.
5: The bottom part is a casing from the belt
6: The bottom part can be attached to the upper part using 5mm machine screw and and a nut (only screwdriver needed, no wrench)
7: The back section of the bottom part is made for deflecting pebbles sliding on top of the casing in direction of the sprocket.
8: The bottom part should be replaceable to enable improving designs.
One could argue whether or not the casing should be as long as i have designed it (it does go past the middle of the tire).
If anyone wants to attempt making the same part, i've put it here:http://heim.ifi.uio.no/yngveha/mc/belt-guard/belt-guard-2.3.zip
Please do note that all use is at your own risk.
I print mine using production grade ABS, and i would not reccomend anything less for anything mounted near the belt.