I have recently had E-4's installed on my "15 Goldwing. They are quiet and smooth. A couple of days ago however, I happened to be riding home in rain. After crossing a rural intersection, and going up a slight grade, I was surprised at wheelspin, accelerating in fourth gear. My thought was that there must have been a bit of oil on the road. Later, again just slightly upgrade, I got unexpected wheelspin in fifth gear! I guess Wings have too much torque! Checked rear tire pressure later; correct at 40 psi.