Well, here it is!
Please excuse the use of file clips, as my other possible solution has not arrived yet. I have to say I'm very happy with this design. It looks a bit more elegant than the previous, is easier to adapt to different sizes, and is easier to shape around caliper brakes. I may still dink around with this one some to create a little more room for the long brake pads I have on this bike, but other than that I am quite pleased!
Now I am just wondering how well this will work in the long run, since I used cotton. Will it want to sag if it gets soaked in the rain? Should I wash and dry in the dryer to "pre-shrink" it before use? I've soaked it and blocked it heavily, so in theory that should have taken out any stretch the yarn may have had in it. I guess I'll just have to road test it and see.