Woman Motorcycle Enthusiast – MOTORESS
Do It Yourself - DIYLEARN TO RIDEMotorcycling

Guide to Reading Your Motorcycle Tire Sidewall Markings

Last Update: 1 February 2023

Guide to Reading Your Motorcycle Tire Sidewall - MOTORESS
Guide to Reading Your Motorcycle Tire Sidewall

Our motorcycle tires are incredibly important. Not only relevant to our safety but also to our motorcycle’s handling. By design, it’s easy to imagine they come with specific compounds, approved safety ratings or markings. These codes are noted on the motorcycle tire sidewall and help riders identify not just sizes, but purchase healthy, approved and correctly certified motorcycle tires.

Reading your motorcycle tire sidewall codes initially came about to identify the tires’ maker. But through the years, government legislation demanded safety markings be posted to help buyers know they are getting a legally approved tire.

Buying and using the right tire for your specific motorcycle or scooter is very important to its load, speed, and overall performance.

The size of the tire needed for your motorcycle (if buying new from a dealership) comes already with the manufacturer’s preferred make/model and profile mounted on the bike.
Further, your owner’s manual provides the specifics you need when it comes to replacing your tires or if you wish to buy a special compound for the track or your long distance tour,  etc.

Motorcycle Tire Sidewall Markings Fall Into Two Groups:

  • Essential markings which tire manufacturers have always used to indicate: make, size and type (including maximum inflation pressure; direction of rotation).
  • Additional markings these have been added over the years per requirements of legislation in the principal regions/country of use.

The markings and ‘code’ is noted on the side wall of both your tires tell quite some information which will differ from country to country. It can be confusing! This code has grown in complexity over the years and you’ll see this as it often combines a mix of metric and imperial measurements. They may also be ad-hoc extensions to lettering and numbering schemes. Each country or group of nations has its own regulating body. Most tires sold in United States or Europe will have a DOT / Department of Transportation date code.

In Europe, the European Tyre and Rim Technical Organisation (ETRTO) and the Tire and Rim Association (TRA) are two organisations which influence national tire standards and aim to align national tire and rim standards in Europe. An example would be “E2” – the “E” indicates that the tire conforms to ETRTO standard R75 and the “2” means that the tire was approved for this regulation by the nation of France.

In the United States, the Office of Vehicle Safety Compliance (OVSC), a component of the DOT (Department of Transportation) is one of the agencies tasked to enforce the Federal Motor Vehicle Safety Standard (FMVSS).

All About Your Motorcycle Tire Sidewall Markings - MOTORESS
All About Your Motorcycle Tire Sidewall Markings

Canada has published tire regulations, such as the Motor Vehicle Tire Safety Regulations SOR 95-148. Other areas of the world may vary, so please seek out the proper information from your nation’s DOT.

Motorcycle Tires Have Their Own Set of Codes

As you might imagine, tires for motorcycles have their own set of codes different from automobile tires. The codes describe:

  • Width.
  • Height/width aspect ratio.
  • Wheel diameter.
  • Load index and speed rating. The load index is the weight the tire is capable of handling when properly inflated. Most tire manufacturers show on the sidewall what that maximum load is so there is no guessing.
  • Maximum air pressure for the tire.

The most common codes and/or ratings you’ll see are shown in this example here. This is what you’ll see on a mid-size sportbike front tire. (below)

Guide to Reading Your Motorcycle Tire Sidewall Markings
Guide to Reading Your Motorcycle Tire Sidewall Markings

Your Sidewall PSI is NOT Your Motorcycle Tire Inflation Rate

Do not make this mistake, the PSI stamped on the tire sidewall is the maximum pressure the tire can be inflated to, not the recommended pressure. There are limits to the inflation pressure a given tires’ structure can take.

Many riders believe that the tire pressure noted on your motorcycle sidewall is “what” the tire should be inflated to. This is incorrect. 

The manufacturer of tire has no idea who will be purchasing the tire and on what specific motorcycle it will go on. They cannot recommend a pressure for your specific motorcycle.  The manufacturer of your motorcycle – sportbike, cruiser or touring bike  – provide the correct pressures for the weight, torque, etc. of your particular model and build.

Become familiar with your motorcycle manufacturer’s inflation guidelines. You can find this information in your motorcycle owner’s manual or commonly, you can find these handy details on a sticker on the bike itself. These, depending on your manufacturer can be located on the swing arm (Honda, Suzuki, Yamaha, Kawasaki), front fork tubes (Harley-Davidson), under your seat (BMW), etc.

Let’s Decipher This Tire Example:

Front Tire: 120/70 ZR 17; Rear: 180/55 ZR 17

Reading Back to Front (Above) Starting With Rear:

  • Rim diameter 17 inches.
  • R = carcass type = “Radial”. This is therefore a radial tire.
  • Z * is the velocity, so more than 240 k/ph or 149 mph. Simplified, this tire is capable of handling any speed this motorcycle can reach, within reasonable limits.
  • 180 as well as the 120 on the front is the width of the tire in millimetres, so 18 cm and 12 cm for the front; when fully inflated.
  • 55 on the rear tire is the measurement from inside the bead (which sits inside the wheel rim holding the tire within it) to the top of the tire is 55% of the tires width. In this example, 55% of 180 millimetres is 99 millimetres, or 3.9 inches. Same formula for 70 on the front.
Guide to Reading Your Motorcycle Tire Sidewall - MOTORESS
How To Read Your Motorcycle Tire

Codes Worth Knowing

  • TL: Tubeless tire.
  • TT: Tube Type – with tube.
  • TWI tread wear indicator (see image below) these can be different depending on manufacturer or tyre brand.
  • 1501: DOT (Department of Transportation), the week of production – in the 15th week of 2001, the band produced. From the year 2000, the DOT four-digit, three digit before. Example: DOT 429 = 42nd week of 1999
  • (73 W): 73 is the carrying capacity and “W” means permitted speed is over 270 km/ h
  • M/C: Motorcycle and scooter tires.
  • (Arrow) means: direction – in this direction, the tire rolls for its mounted so it’s not put on backwards. If the tire were mounted incorrectly it could result in a dangerous situation, especially on a wet surface where the tire would be unable to dispel water away from the bike.
Guide to Reading Your Motorcycle Tire Sidewall Markings
More Motorcycle Tire Sidewall Codes

 

Always check and confirm your mounting direction, particularly if your dealership is mounting your new tires. There have been cases (usually happening in haste) when the mechanic puts the tire on in the wrong direction.  Additionally, check the inflation (PSI) as like under inflation, one of the biggest mistakes people make with their tires is to exceed maximum levels and manufacturer inflation specs leading to poor handling and premature wear.

 

 


Speed and Load Chart

Motorcycle Tire Speed and Load Chart on motoress
Motorcycle Tire Speed and Load Chart

If you have an older motorcycle vintage or classic, chances are you’ll have a diagonal tire tread such as pictured here: Front wheel: 3.25 S 19

Older Motorcycle Classic or Vintage Tire - MOTORESS
Older Motorcycle Classic or Vintage Tire

Reading Above Tire Back To Front:

  • The last digit is the cross-section of tire rim to rim (rim diameter) in inches – so 19 is the rim diameter.
  • S means class speed to 180 km/h.
  • 3.25 is the tire diameter in inches.
  • Noted as tube tire and DOT rated.

Radial or Diagonal (Bias) Tires?

All About Your Motorcycle Tire Sidewall - MOTORESS
Radial or Diagonal (Bias) Tires?

A radial construction, the ply cords radiate out at 90-degree angles to the centre line of the tread. In addition, the crown is made from layers that form a belt. As a result, the crown and sidewalls have their own particular characteristics.

A diagonal or bias tire’s carcass is made from layers of ply cord running diagonally to the centre line of the tread. The layers are placed so that the cords create a criss-cross pattern. The whole structure is uniform throughout; the crown and sidewalls of the tire have similar mechanical properties.

Two Kinds Of Tires For Specialised Performance

Due to their soft sidewalls, the crowns of radial tires stick to the road on contact. Their footprint, shorter but wider than that of a diagonal (bias) tire, provides added grip when leaning in heavily on corners. The pressure of the air in contact with the tire surface is distributed more effectively with radial tires, which results in more even tread wear over time.

Radial tires also provide greater comfort at higher speeds, once again as a result of their soft sidewalls, which absorb the impact of imperfections on the road surface. On the other hand, diagonal (bias) tie are able to carry a greater weight because their sidewalls are more rigid. At high speeds, bias tires can become so deformed that their performance is affected. Ultimately, bias tires are suitable for vehicles travelling at moderate speeds, with small to medium-sized engines and flexible chassis. They are also suited to heavy or heavily loaded motorcycles. Radial tires are needed for more powerful vehicles with very rigid chassis and for more sporty purposes. They allow you to reach ZR speed ratings, above 150 mph.

Remember!

The manufacturer of your motorcycle has chosen the right tire which in itself has been engineered to operate at a safe temperature in a stated range of inflation pressures, at recommended maximum load, and in a stated speed range. Best to keep to their expert advice and follow their instructions.

And always check your motorcycle tire pressures when they are cold.


Make Your Mark in A Slingshot

RELATED TOPICS

Lane Splitting and Lane Filtering: Understanding the Distinction

MOTORESS

Mastering The Thrills: How to Ride An Electric Motorcycle

MOTORESS

How To Avoid Wildlife Collisions – Essential Tips for Every Motorcycle Rider

MOTORESS

Complete Guide to Riding Your Motorcycle at Night

MOTORESS

10 Key Approaches For Managing Risks When Riding On Expressways

MOTORESS

Your Guide To Riding in Hot Weather

MOTORESS

Leave a Comment

* By using this form you agree with the storage and handling of your data by this website.

We use first-party and third-party cookies for analytical purposes and to improve your experience. ACCEPT For More Information consult our cookie policy.

Translate MOTORESS