TIRE WIDTH EQUIVALENT CHART
WHAT IS THE RELATIONSHIP BETWEEN SIZES AND DIFFERENT TIRE SYSTEMS? USE THIS CHART TO COMPARE THE VARIOUS WIDTHS---AND TO DETERMINE POSSIBLE REPLACEMENT CHOICES WHILE THESE MEASUREMENTS ARE USEFUL THEY ARE NOT GOSPEL BECAUSE EXACT INTERCHANGEABILITY IS STILL AN IMPLIED MEASUREMENT
LETS TAKE A SPECIFIC TIRE: 120/70VR-18 : THE 120 IS THE METRIC SIZE THAT CONVERTS TO 4.50" THE PERMISSIBLE RIM WIDTHS THAT THIS SIZE USES IS 2.15/2.50/ AND 2.75 THE 70 IS METRIC FOR 2.75" WHICH IS THE MAXIMUM RIM PERMISSION WIDTH THE V IS A RATING FOR MPH (130 MPH, FOR EXAMPLE) THE R IS (IN THIS CASE A DUNLOP) IS FOR RADIAL THE 18 (LAST TWO DIGITS IN A TIRE SIZE) IS ALWAYS EXPRESSED AS INCHES, OR, IN THIS CASE AN 18" TIRE
THE PRACTICAL IMPLICATIONS OF THIS IS THAT YOU NEED TO SELECT A TIRE SIZE THAT IS COMPATIBLE WITH THE MOTORCYCLES' LIMITATIONS. FOR EXAMPLE YOU MAY WANT TO ADD SOME WIDTH TO A NEW TIRE MAKE SURE THAT THE NEW (WIDER) TIRE WILL FIT INTO THE SWING-ARM DIMENSIONS. SOMETIMES A SILLY MILLIMETER IS TO MUCH
THEN IT GETS STICKIER---WHEN A LOW PROFILE IS OFFERED A PROFILE IS THE MEASUREMENT BETWEEN THE MID GROUND SURFACE AREA AND THE RIM-BEAD. LOW PROFILES HAVE A SHORTER MEASUREMENT THAN STANDARD PROFILE A STANDARD PROFILE IS IMPLIED IF THE TIRE HAS NO "LOW PROFILE" NOMENCLATE LOW PROFILE TIRES PLACE THE CENTER OF GRAVITY OF THE MOTORCYCLE (LOWER) THAN (STANDARD)
TIRE DIMENSIONS CHART
THE ALPHA NUMERIC (MG, FOR EXAMPLE) MAY VARY AND WILL BE EXPLAINED ON THE TIRE PAGE THAT IT APPEARS ON (ON THIS SITE)