Funny you should mention dirty wheels. I was reattaching the part that hangs behind the front coupler. Similar to a bumper on a car. Anyway I turned the shay over to glue it back on and I noticed a large amount of hair on the running gear. I cleaned everything with a camel's hair brush. If that doesn't help, it sure won't hurt. I keep my shay lubed, but I never thought about keeping it clean.
Jim
Jim