I am looking into what rear tire to get next, and wonder if 120/90 is actually a better choice than 120/80, as it raises gearing between 3 and 4 percent, or slightly more than 1 tooth less on the rear sprocket. Is there any disadvantage to a 120/90 vs 120/80 that I am unaware of? I already have longer shocks, so fender clearance is not an issue. Both Bridgestone BT45 and Avon AM26 tyres are available in 120/90, so that is no problem.