2001 K1200LT, Front tire, 18,ooo mi with lots of tread remaining, no wear markers showing, no cupping, always run 42 PSI and check every time I ride. The bike is so smooth any strange vibration is immediately noticeable. Today while riding I felt a little vibration while riding below 50 mph. Vibration almost unnoticeable above 50 mph. I thought it was road surface vibration at first and then tested feeling through handlebars by very lightly resting hands on grips and could feel the vibration more when letting loose. I decided to stop and check things over. I thought it might be the start of a rear end failure, but suspected a tire malady because the vibration seemed to be related to tire rotation speed. I put the beast on the center stand and checked the front tire first. I pulled the tire through 360 degrees of rotation using the wheel spokes - and found a big lump in the center of the tread about five inches long and two inches wide. I suspect this problem was caused by me hitting a rock in the road on a previous ride. When I checked the tire pressure this morning before riding I inadvertently put in a few extra pounds attempting to add a couple pounds. I believe the extra pressure made the weak spot, where the tire hit the rock, more pronounced. The area of the bulge also has a horizontal split about two inches wide in the center of the tire tread - probably from the rock strike. I decided not to continue the ride - rode home on the back of a Road Star, about 25 miles, and retrieved my trailer to haul the cripple home. I believe this is a positive testimony for the strength of the ME 880 carcus. I probably rode on that weak tire for 50 miles at speeds up to 75 mph. The strange vibration gave me enough warning to stop and check out the situation before experiencing a total tire failure. I believe I will now do a more thorough check of my tires in addition to the pressure check before each ride. I will be replacing the failed tire with another ME 880. The worst part of this experience was the ride on the back of that Road Star - I pitty the guys wife.