Throwing this out there as some humor, but also a "well look at that.."
While sitting in the lawn chair by the bike and looking at how frickn far I have to go to get my STD together, and killing a few, I noticed that the black frame areas was quite dusty/dirty. - Just on an impulse within reach was a container of Armor All Leather wipes, and I grabbed one of the wipes and started cleaning with that.
Well.... dayummm.... It does a great job. I did some more today, and I think I found good way to clean up black frame stuff. -- Sometimes the best discoverys are made while drunk..lol..
