Jun 25, 2013 · Appreciate the help. The DR650 front tire is more often referred to in it's Metric size: 90/90-21". In SAE, that would be 3.00-21". Most tires for sale use the 90/90-21" reference. They are identical size. 120/90-17 or 130/90-17. Either size is fine on the DR650. the 120 size is OEM size but a 130 works perfectly as well. a58Bh.

90 90 vs 90 100