Fitting a chainguard to a bike and its effective operation have been a source of constant frustration for me and apparently others, including manufacturers and bike shops. At some point I bought a lot of 12 or so guards from a Geman bike shop that were apparently misfitting customer bikes and taken off. Out of that variety of guards, I managed to fit one to one of three bikes I could use them for. The variety of frame details, derailleurs and cranksets challenges the guard design.

With that frustration, I went ahead to come up with something custom for my main bike. I started with a Driveline ring off Ebay that had its center though open. After a while I decided to fill it and I acquired alu sheet. The sheet was large, though, and after cutting the fill circle, I was left with quite a bit of material and then went to add the back and front using left-overs and L and flat bars left from other projects. Since this has been holding solid for over a week, I thought I'd share it. The guard works so effectively that there is now no difference in the appearance of the left and right legs of pants. I further completely ceased to care on which side of the bike I am standing.