Greetings. Long time no post....
My 2014 FJR is pushing 18,146 miles. A year ago and 4000 miles ago, I replaced a Front tire, a Michelin Road PIlot 4 due to cupping/scalloping but it had 8,000 miles on it.
Now, the tire I put on , A Road 5, has this ridge on it. Like someone glued a big rubber band to the outside. See pic. I am going on a trip from Spokane to Utah for two weeks in Sept so I put on a new Road 5 GT.
I am trying to think if I did something wrong but I check the tire pressure on a regular basis. I do carry about 50 lbs of camping gear on the back when I tour. I ride conservatively. Could this be a bike issue? Steering head bearings not torqued right? The bike rides like a dream and tracks true....Any ideas?
Not a darn thing wrong with your tire. That is just the way modern radial (and bias) high performance motorcycle tires wear. Just because it ain't pretty doesn't mean there is anything wrong.
Scalloping is a pattern which repeats every tread block, cupping spans multiple tread blocks. Feathering is a form of scalloping due to the tire being forced to roll in a direction other than the direction it is pointing. Tread blocks flex and squirm and wear funny as they contact and release the road.
Motorcycle tires will scallop no matter what you do because the rolling diameter of the tire is different across the contact patch. Motorcycle moves at one speed but the speed across the contact patch is continuously changing because the distance to the axle is changing. Some of the contact patch must scrub. Tread blocks flex during scrub. Odd wear patterns emerge.
Higher inflation pressures result in a narrower contact patch. Narrower contact patch has smaller difference in speed on the surface of the tire from one side to the other than a wider contact patch. So you could reduce the scalloping with higher tire pressure but at the cost of less traction from a smaller contact patch.