A little background first. I was on my 2011 Vaquero enjoying a 6000 mile trip and pulling a 400 pound camper out west through Co, up through Wy and back through SD to PA.. Mid trip I needed a tire. I called ahead to get the tire from a dealer. After having the new rear tire installed, I took off to continue my trip. At 75mph, I got a death wobble that almost put me down. If it had not been for my 41 years experience I would have crashed. I rode back to the dealership and come to find out they put a radial tire on my bike. I had ordered a bias ply. They said it doesn't make a difference. I told them it doesn't if you are not towing anything. The side walls on a radial are softer and flex easier. It was enough to almost put me down. They replaced the rear tire with a bias ply and I was fine from there on. I ran 80 Plus in SD. Have any of you experienced an issue between radials and bias ply tires?