Join Date: Feb 2011
Location: Syracuse, NY area
Cause of cupped front tire?
With about 8200 miles on the front Anakee III's on my K7 Wee, I noticed significant cupping. Seeing how I needed a new rear tire at that time, I purchased a set of Metzler Tourances. While getting the rear tire mounted, i mentioned to the tech that as soon as I got the rear tire mounted, I would be returning to have the (cupped) front tire replaced, even though it still had about half of it's tread left. He suggested that I check my steering stem bearings first, as a slightly loose set of bearings will cause cupped front tires. He mentioned that he had learned this from a Dunlop rep.
The tire tech was right- the bearings were slightly loose. Not enough to feel slack in the forks when tugging on them, but more than desired. I went to the local Home Depot, bought a foot of 1 1/4" I.D. black iron pipe and proceeded to make a tool to adjust the special nuts that adjust the bearings. (Thank you for the instructions, Black Lab!) The bearings were tightened, and after another couple of thousand miles, the cupping was gone! The tires has about 12K miles on it now, and it still has 4/32" of tread left.
To summarize, if you are experiencing cupping of the front tire, check your steering stem bearings! Most likely, they are too loose.