B- Aspect Ratio. The smaller the number the lower profile of the tire. In metric this is a ratio between height and width. ex. A 170/80 means the width is 170mm, and the height would be 80% of that. )

The Section Width is the width of the tire measured from the middle of the side walls (above the bead, below the tread). TL is a descriptive abbreviation. {See the sections below for more info.} It indicates that the tire is meant for a tubeless application. The majority of modern motorcycles use tubeless tires. If your bike has wire spoke wheels you need to use a tire designed for use with a tube inside. All those spokes and nipples are not air tight. Enter the time by pressing "Enter a time". The time is placed in the top window, replacing what was there. Not all manufacturers will add the TL to indicate that it is tubeless. It was used more when they were not as common as today. Inch Size Format Size may be indicated in inches, metric, or by letters (alpha). It is helpful to know how these compare with each other so you can compare different brands of tires and see which might be the best fit for your bike. This chart shows the approximate comparison of the different size indicators. Motorcycle Street Tire Sizes Conversion ChartBritish motorcycle rims (Triumph, BSA, Norton etc.) are marked with a letter and number designation. This is helpful to know what tires you can mount on your rim based on the manufacturer's specs. WM0

The vast majority of tires manufactured and sold today come with metric sizing. The tire size we will use for our example is a 120/70ZR-17TL. It can also be written as 120/70Zx17TL or 120/70ZR17TL. The Aspect Ratio is the tire section height divided by the section width (not tread width), multiplied by 100. The section height is measured at the center of the tire crown. The tread width is usually greater than the section width. The section width is measured from the middle side walls (above the bead, below the tread). It is The speed rating is explained in detail below, but in our example, a speed rating of H means this tire is rated for speeds not to exceed 130mph or 210kph.The calculator adds or subtracts input durations from the time in the top window. You first enter a time in 24 hour format Dirt bike tires are sold in both metric and inch sizing format but do not always have a speed rating. More often they are rated by terrain. The Ply Rating is a descriptive abbreviation. It refers to the number of plys (layers) that make up the tire. For more on descriptive abbreviations, see sections below. For specific strength of the different ply tires, refer the tire manufacturers literature.

The Speed Rating is explained in detail here. For our example a speed rating of Z means this tire is rated for speeds exceeding 149mph. To most people, the numbers and letters on the side of their tires are cryptic and indecipherable. These motorcycle tire sizes comparison charts below will help you understand the codes on the side of your tires to be sure you know which tires you are currently using, and which others will fit your motorcycle.The above tire size conversion chart does not mean that these tires are universally interchangeable. They are to give you a point of reference when upgrading your older tires. Consult your motorcycle’s manual or manufacturer’s customer service The section width and rim size are defined in the same manner as described for the Alpha and Metric size formats. However, the U.S. military prefers not to say 24:00 - they do not like to have two names for the same thing, so they always say "23:59", which is one minute before midnight.

Also, inch size format tires are all bias type. They do not come in radial. The size will will use for this example is 4.60x17H 4PR. You may also see this written as 4.60H-17 4PR. 4.60 In addition to the information listed above, tires can contain Load Index or Rating info on the sidewall. This refers to how much weight a tire can safely transport. It includes the weight of the bike and rider(s). Not all tire manufacturers make tires in all load indices. Dunlop, for example, starts at 33. Load Sometimes a catalog will list a tire as TL, BL or RWL. These have nothing to do with the size or handling. They are strictly descriptive. They describe the look or another feature of the tire. Abbreviation In railway timetables 24:00 means the end of the day. For example, a train due to arrive at a station during the last minute of a day arrives at 24:00; but trains which depart during the first minute of the day go at 00:00. Some manufacturers put the speed rating at the end of the size and do not indicate if the tire is tubeless or not. In that case the size would look like this 120/70-17Z. 120The following chart shows some common tire sizes, including their width and the diameter. Very handy when choosing which tire will fit your bike, or which motorcycle rear fender to buy to fit the tire you want to run on your new build! Enter a time in three parts: the hours in left field, minutes in the middle, and seconds in the right field. multiplied by 100 to give you a whole number for the tire. So instead of .9 the tire is stamped 90. The motorcycle tire size will also indicate what size rim strip and motorcycle inner tube is needed. Rim strips are rubber strips that go around the rim, covering the inside edges of the spokes, before the tire is mounted. They help protect the inner tube from a potential puncture from continual wear against the spokes. Inner tubes are common, though tires are also run without tubes on many modern motorcycles with mag wheels. How to Read Motorcycle Tire Sizes?