3350 posts · Joined 2009. #23 · Apr 18, 2021 (Edited) I used 90/100 Michelin Enduro tyres for years,but my 500 came with a Metzeler 90/90 front. It didn't give as much comfort as the 90/100's but was more accurate,could change lines faster and best of all I hardly ever lost the front end.The 350 is delivered with a 90/90/21 and a 140/80/18 in Europe. While it depends on your riding style, liking or just the playground where you ride you can put on a 80/100 or even 90/100 front tyre. Get a 140 rear, no problem. You will find out that a 100/100/18 Dunlop MX52 is as wide as a 140/80/18 Golden Tyre. 120/70-R14 tires are 0.24 inches (6 mm) larger in diameter than 90/90-R14 tires and the speedometer difference is 1.1%.
80/90-R21 tires are 0.94 inches (24 mm) smaller in diameter than 120/70-R21 tires and the speedometer difference is 3.4%.