I ride a BMW 1200LT with Hannigan conversion. Tire selections for BMW LT are limited: front: 120/70/17 B17 and back: 160/70/17 B17. On this forum I see where folks recommend putting a back tire on the front (backwards) to give them longer wear life, better handling etc. My issue is that there is no back 120/70/17 size tire that I can find. I can find a Michelin 130/70/17 back tire but don't know what that will do. So (1) anyone know of a 120/70/17 back tire or (2) if the 130/70/17 is acceptable? Thanks in advance