Here I am again, helmet in hand, to ask some advice on a couple of minor issues.
1) I was noticing that I have a black streak caused by the brakes on my back wheel. It is about a complete circle on the back wheel, caused no doubt by my tendency to use the back brake as a "slow-down" brake approaching a turn/curve. The front doesn't have black marks all the way around because I use it more as a "stop-now" brake. (I hope that makes sense) My question is, what is the best way to clean up the aluminum rim?
2) This is my first bike with external gears (had a 3 speed once and it was terrible....about 55 years ago). I think I am finally getting them down (you wouldn't believe that if you had seen me shift to the low gear of the crank-set while putting too much pressure on the pedals and it went off on the inside.....and I had no idea how to fix it...logic worked it out in a couple of minutes). Today while riding I pulled another dumb stunt and was "cross chained" for a few seconds. Which brings me to the point. It seems to me to avoid cross-chaining I should use the following combinations: 1 on crank-set, 1, 2 or 3 on rear 2 on crank-set, 3, 4, 5 or 6 on rear, 3 on crank-set, 4, 5, 6, or 7 on rear. Is that close to right? (This is with Shimano, 7-speed: 14-34 rear cogs and 42/34/24 chain-rings)
I hope I expressed my questions so they make sense to everyone. Thanks for your advice.