Keep in mind that just the bag yokes (even with the correct laces) will eventually mar the finish of your bike. I cut and hot glued some felt covered neoprene to the back of the straps of mine after I noticed a damaged area of the fender. It will continually saw back and forth with movement. The leather alone will cause damage, but there's also the chance of trapped sand, dirt, etc. that would speed up the process.
