Something to think about when selecting tires besides the size, that is important is the load rating and the speed rating. A lot of the peds are modified with kits,carbs,exhaust,porting and can run much faster than the original 20 to 30 mph that the tires that were originally on when the bike was sold new were rated for. When I looked into tires for my 1979 Honda Express NC50 that came with 2.25x14 30mph rated tires and load rated for 200lbs, I ended up buying IRC 70/90-14 tires that could carry 260lbs each and were P speed rated for 93 mph. Kind of important for safety, when I checked the rear tire with me on the bike the scale showed 200lbs. Better to run a tire under it's rated load than at the limit. Since the bike has a DR kit and a Puch cylinder Super Street high compression head it runs faster than the original 32mph prekit days. So having a good safety margin with high speed rated tires on the bike that can hit 50+ mph makes for peace of mind when blasting through the twisties. These tires are motor cycle tires that have sipping? like sport bike tires, also good in the wet, handle great and stop better that the old tires ever could.