Speaking of brake wear, I noticed there was quite a large ridge around my rear disk, enough so that I actually had to push the piston back a little to enable sliding the caliper off. I went ahead installing the used but still useful rear tire and put everything back together but I kept thinking about that ridge. I decided to mic it and got anywhere from 4.1 - 4.2 mm thick from various places around the disk, then I looked up the minimum thickness specification in the service manual - 4.5 mm, oops! I've got a replacement disk on order. The bike has 72,000+ miles on it and I am on my third set of rear pads, which are still relatively new (<5,000 miles). Seems like I should have been checking the disk thickness much earlier, perhaps around 50,000 miles? Upon ordering I noticed there is a superseded part number; 23P-2582W-01-00 replaces 23P-2582W-00-00. I wonder if Yamaha has improved the disk material for better wear? This is the first time I've worn out a disk on any of my bikes, including my previous ST1300 which was still in spec at 150,000 miles and also has linked brakes. I also put about 150,000 miles on my previous, previous ST1100, though it had first gen independent ABS brakes.