Mike....not trying to be an alarmist here.... but I was ordering a 130/70 for my Speedmaster today and presented your question to a very knowledgeable Triumph tech and he commented that the rear tire tread "may" disperse water differently than a front tire tread. Hence the difference in tread pattern from front to rear. He advised me not to use the Avon, so I ordered the Dunlop instead. Your milage may vary!
