Motorcycle Tire/Tyre Tech 101
Total Motorcycle tire/tyre guide for all motorcyclists.
Motorcycle Technology and Information
|F or FR||Front Tire|
|R or RE||Rear Tire|
Raised White Letter
Slim White Stripe
Wide White Wall
|NWW||Narrow White Wall|
Tube Type Tire
Tire Size Conversion Chart:
Motorcycle Tyre/Tire Technical Details
The Role of a Motorcycle Tyre
Tread pattern: The grooves in the tyre enable it to evacuate water from the contact patch when the road is wet. The more grooves there are, the better the tyre will perform in the rain. A worn tread pattern with few grooves indicates that the tyre should be replaced.
Rubber mix: The rubber’s chemical makeup determines durability and grip . A softer rubber compound promotes cornering grip and traction. A harder rubber compound wears more slowly. Silica -reinforced compounds excel in the wet.
Profile: The tyre’s profile (cross-section) can have a strong influence on the dynamic behavior of a motorcycle. Sport tyres promote quick steering and extreme lean angles. Street tyres emphasize stability and low-speed maneuverability.
Tread area: The only point of contact between the motorcycle and the ground. The rubber mix in this area is often different from that on the tyre’s sidewalls. In addition to absorbing bumps to ensure a comfortable ride, the center of the tread is the part of the tyre that must be the most resistant to wear.
Carcass: Supports the load of the motorcycle, ensures stability and contributes to comfort . The carcass must allow some deformation to absorb road shock. Radial carcasses are more flexible than traditional bias-ply construction and thus offer superior damping.
Radial construction: A structure composed of carcass plies perpendicular to the direction of rotation (90 degrees), with additional cross-plies on top and/or a crown ply at 0 degrees. A radial is made up of fewer components than a bias-ply tyre. Thus it is lighter, and offers improved handling. Also with fewer components, there is less internal friction and reduced operating temperature at high speeds. With a radial tyre, designers can use more aggressive tread compounds that combine durability and grip.
What is a tyre?
A tyre is a composite structure, i.e. an assembly of interdependent materials with very diverse properties whose construction requires a high degree of accuracy.
It is composed of the following materials:
– an airtight, synthetic rubber liner
– the carcass ply
– the filler
– crown plies
– the tread
These elements are combined through vulcanization into a single unit, using a mold that also forms the tyre’s final appearance (tread pattern and markings).
The 6 Functions of a Tyre
Today, the level of technology in tyres and motorcycles is extremely high. Riders often forget that the tyre is the only point of contact between the bike and the ground, and that it must perform multiple tasks including steering, carrying a load, absorbing road shock, rolling smoothly, transmitting mechanical inputs, and wearing evenly.
STEERING: The tyre must steer predictably, regardless of the road or weather conditions. The motorcycle’s trajectory depends on the directional stability of the tyre. The tyre should transmit steering inputs without drifting off the intended line. Every bike has a specific recommended inflation pressure for each wheel. Correctly adjusting pressure for both front and rear tyres helps ensure steering stability and precision.
LOAD CARRYING: The tyre supports the bike at a standstill and while in motion, but must also withstand considerable load transfers during acceleration and braking.
SHOCK ABSORBING: Tyres roll over obstacles and damp road shocks, ensuring the rider’s and passenger’s comfort as well as protecting the bike. The tyre’s greatest asset is its flexibility, particularly in a vertical plane. The elasticity of the air inside the tyre helps it to absorb shocks from obstacles and irregularities in the road. The correct pressure thus helps achieve a desirable level of comfort as well as accurate steering.
ROLLING EFFICIENCY: Tyres should roll smoothly with minimal rolling resistance for a feeling of control and with steady, progressive wear.
MECHANICAL GRIP: Tyres transmit the bike’s mechanical forces of horsepower and braking. The few square centimetres that constitute the contact patch can make all the difference in a bike’s performance.
WEARING: Tyres need to maintain a dependable level of performance throughout millions of revolutions. Tyre wear depends on many factors (load, speed, condition of the road, vehicle maintenance, riding style…) but especially the quality of the contact patch. Air pressure plays a major role, affecting:
– the size and shape of the contact patch,
– the distribution of the mechanical forces on various points of the tyre in contact with the road.
These six functions determine a tyre’s safety, comfort and economy. You expect them to be present throughout the lifespan of the tyre, but you must take certain precautions. The tyre needs air to perform and to last, so it’s necessary to check inflation pressure regularly. Every tyre loses air, molecule by molecule, because of rubber’s natural porosity. Accidental causes such as valve or rim damage often accelerate air loss, as will small cuts in the tyre tread or sidewall. Air pressure affects every aspect of the tyre: safety, economy and riding enjoyment. The wrong pressure can degrade performance in all areas.
Routine pressure checks can prevent many worries.
Special Thanks to Michelin Tire
The 6 Functions of a Tyre
– BIAS tire THE MOST POPULAR MOTORCYCLE RIMS
Also indicated as conventional or x-ply tire. The structure of this tire is made of a carcass where, depending on the different speed and load specifications, one or more layers are overlapped. Each layer is made of textile cords coated into rubber and the overlap angle is designed in order to confer the tire the required dynamic characteristics.
– BIAS-BELTED tire
The structure of those tires is realized with a conventional carcass and a belt made of one or more crossed layers. The difference between carcass and belt is given by the different goals that they have to fulfil and consequently the different materials that are used: the belt is mainly made by Nylon and has to reduce the dynamic deformation due to the centrifugal forces, while the carcass has to mainly give the tire its contour.
– BELTED TIRE WITH RADIAL CARCASS (90°)
The main difference towards the bias-belted tire is given by the structure of the carcass that in this case is radial. This means that its cords are wrapped radially around the tire, means from one shoulder to the other. In this way low-section tires can be realized, giving big advantages in terms of cornering stability, reduced weight and high-speed performance.
– 0°-STEEL BELTED TIRE WITH RADIAL CARCASS (90°)
Patented technology by Metzeler realizing the structure of both front and rear tire using a radial carcass and a single layer belt made of steel. Considering the rolling direction of the tire, the belt is winded circumferentially around the carcass giving an angle close to 0°. The advantages coming from the use of steel are its extremely high rigidity and the possibility to tune the winding spacing giving a differentiated stiffness distribution from shoulder to crown.
Special Thanks to Metzeler
TREAD PATTERN AND COMPOUND
The tread pattern is the outer part of the tyre, in contact with the road. The profile and rubber compound are chosen based on the use of the tyre. The rubber compound especially, requires a high level of experience and technical know-how. In general with a harder rubber compound mileage increases, and grip decreases. The softer the rubber compound, the more grip a tyre has, but the mileage is reduced. Of course, mileage depends also and greatly on the average speed driven and on the asphalt conditions.
The carcass is the basis of the whole system and gives the tyre its form. The materials used are one or more plies of Nylon or Rayon or Polyester. The main function of the carcass is to provide a flexible driving forces from the bead to the tread.
This is the component by which the tyre is fitted on the rim. It is reinforced by steel cores coated in rubber. They aid in transmitting the accelerating and braking tor-ques, as well as to mechanically connect the tyre to the rim and to ensure against loss of inflation pressure.
The speed index (SI) indicates the maximum speed the tyre is homologated for. Even if PIRELLI tyres allow high speed performance ability, we do not recommend the use of any of our products in excess of legal speed limits. Tyres can have the same pattern and size, but a different speed rating, this is due to the tyre construction and therefore they will perform differently. When selecting your new PIRELLI motorcycle tyres, be sure to choose the right speed rating. Before buying, consult the fitment chart and the technical data in your PIRELLI manual or call us directly. Maximum speed capability varies from size to size, but is always equal to or greater than that of the original equipment tyres when fitted in accordance with PIRELLI recommendations. The use of a tyre with a higher speed rating (e.g. “H” instead of “S”) is allowed only if listed in the fitment chart. Especially in cases where the speed rating exceed 210 km/h, the PIRELLI recommendations must be respected!
Tyres are offered in different load carrying capacities. It is extremely important not to exceed the max. load rating. You must take the weight of the motorcycle, the weight of any optional equipment, as well as the weight of a passenger into consideration before determining what the “Load Capacity” of your tyres should be. A tyre’s load carrying ability can be reduced by underinflation. You can overload a tyre even if it is the size specified by the manufacturer. Before travelling, you must calculate the total weight (luggage, equipment, passengers) to be added to the motorcycle.
Tubeless tyres require a special bead seat, because the beads have to form an airtight seal on the rim. Not all cast wheels, aluminium or magnesium, are suitable for tubeless tyre fitment. Do not mount tyres without tubes, unless the wheel manufacturer recommends it. If a tube is inserted, it is then possible to fit a tube-less tyre to a tubetype rim.
Centrifugal forces work on the valve stem. At high speeds they have the same effect as pushing on the valve with your finger. The tyre can deflate. The valve cap is the only part preventing it. Normally this phenomenon happens only at very high speeds. But an old or low quality valve stem can open at speeds lower than 200 km/h. Therefore the cap should always be tightly closed. PIRELLI suggests the use of airtight metal caps with rubber seal.
LOAD INDEX AND SPEED INDEX
The rating indicates the maximum speed the tyre is homologated for. The indications regarding speed rating and load capacity in the operating manual of the motorcycle must be followed. Tyres fittes must be marked with the same or higher index. The load and speed indices (SI and LI) are indicated in the technical data for each PIRELLI tyre.
The name given to PIRELLI street tread compounds designed for competition use. One of the features of the PIRELLI Corsa is a much higher level of grip in comparison to the standard tyres.
This marking stands for Department of Transport (USA) and the code following DOT indicates that the tyre meets all the requirements set out by the US Dept. of Trans-port. The last three numbers indicate the production date of the tyre. Example 509= produced in the 50th week of 1999.
Abbreviation for ”motorcycle”. This marking is to ensure there is no confusion when mounting motorcycle tyres of similiar rim diameter to automobile tyres. Motorcycle tyres must not be mounted on automobile rims as there are important differences between motorcycle and automobile rims.
The abbreviation for “Not for Highway service”. Motorcycle tyres with this marking are only for racing or off road purposes cannot be used on public roads.
A ”Ply” is the individual textile layer in the tyre carcass. The carcass is made up of one or more plies.
The designation, ply number, refers to the tyre load index. The PR marking is now only applied by the Japanese standard (JATMA. European standards (ERTO) do not require motorcycle tyres to carry a PR number. The Japanese standard can be compared to the European standard as follows: 4PR – normal version 6PR – reinforced version The PR number does not refer to the number of plies in the tyre.
(abbreviation rf. or reinf.) refers to the construction of a tyre, increasing its load capacity.
Abbreviation for tubeless. Tyres with this indication, when fitted to a tubeless type rim do not require a tube.
Abbreviation for tubetype. Tyres with this indication must have a tube installed.
Many countries worldwide have different legal regulations regarding the minimum depth of the tread pattern of a tyre.
Treadwear indicator, indicates minimum level of tread depth for safe use. However many countries have different regulations regarding minimum tread depth.
The sidewall is the “name plate” of a tyre. The combinations of numbers and letters indicate not only the name of the tyre but also the maximum speed and load allowed. In the transmission of ircumferencial and side forces, as well as bump absorption the side wall plays an important role.
REPLACING A WORN TYRE
Remember, precise matching of front and rear tyres is necessary to obtain optimum performance and handling. When fitting a new front tyre, check the wear on the rear tyre. A new front tyre combinde with worn rear tyre may cause instability. Please bear in mind that many other factors can affect the hand-ling of a motorcycle, including the weight and height of the rider, and the addition of luggage of fairings. Please consult the motorcycle manufacturer before making nonstandard modifications.
TYRE MOUNTING – IMPORTANT INFORMATION
These tyres are only to be used on vehicles for which motorcycle tyres were originally stipulated by the manufacturer. Any other use can be dangerous. Check if the tyre has directional arrows. If it does, you must mount the tyre so that the arrow points in the direction of rotation. Some PIRELLI tyres have a red dot on the sidewall. This indicates the lightest point, and should be positioned next to the valve. To clean or lubricate the bead, use tyre mounting lubricant or soapy water. To seat the bead: remove the valve stem core and inflate the tyre. For safety reasons do not inflate motorcycle tyres to more than 50 psi (3,5 bar); for scooters tyres do not exceed 150 % of the indicated maximum pressure. Be sure to reinstall the valve stem core and inflate the tyre/tube to the recommended riding pres-sure. Check the bead control lines for proper seating. If the beads are not properly seated, you will have to deflate the tyres/tubes and repeat the above procedure.
VEHICLE FITMENT AND SIZE MATCHING
When choosing tyres always make sure that the selected tyres has: oa load capacity which is never lower than the maximum permitted load for the wheel on which the tyre is to be fitted (front – rear), including the passenger, luggage and accessories;
a maximum speed higher than the approved maximum speed of the motorcycle at the maximum load which is designed to carry;
an external diameter very similar to that of the original set of tyres;
a section width which does not interfere with the mechanical parts of the vehicle under any running conditions, especially at high speeds;
high performance motorcycles should be fitted with front and rear tyres of a compatible type in order to avoid dynamic instability.
NOTE: Variations of tyre size from those indicated by vehicle manufacturers, even if tech-nically possible, must be in accordance with existing local regulations.
Be sure to align your wheels every time the rear wheel is removed or the chain adjusted. Every rotation of an incorrectly alignes wheel results in additional tread wear, decreases tyre mileage, and affects steering and concerning.
Elastic bodies like tyres, cannot be constructed in a perfect, circular form, with per-fect balance. Therefore, be sure to balance a new tyre after installing it. There are two ways to balance a tyre: static and dynamic balancing. Static balancing can be performed without rotating the wheel, and also measures the deviation of masses with respect to the wheel’s center plane. PIRELLI recommends dynamic balancing for rims over 2,5 inches in width.
Special Thanks to Pirelli
Motorcycle Tyre/Tire Maintenance and Information
Keepping your tires correctly inflated
offers a lot advantages to the rider.
Motorcycle Tire, Tyre Maintenance
Tip: Keep a low pressure tire gauge (0psi – 80psi) in your bike tool bag at all times. Try to remember to check your tire pressure everytime you fill up for gas.
Keep your tires correctly inflated. A tire that is very under-inflated generates a lot of heat which can lead to a blow out. Tires that run too hot also wear out more quickly. The most common motorcycle breakdown is for tire damage.
Purchase a pencil-type tyre gauge and use it regularly until you instinctively ‘know’ what your tyres feel like correctly inflated. Use of the gauge and visual inspections must become second nature.
Replace your tires sooner rather than later. If tread depth is 1-2mm it is time to replace your tires. Take a tip from the mad sportbikers and the canyon racers – they never skimp on their tyres as they are often all that stands between them and the pearly gates.
Dry Rotting- or “cracking.” Usually means that the tires are old and/or the bike has not been in covered storage. Real “light” cracking may be ok, but basically if there is excessive dry rotting, you should get new tires.
Tire Care and Tyre Tips
Tires on motorcycles, like any vehicle, play a vital role in the performance, handling and safety of the bike. Many times we tend to ignore the necessary maintenance needed to keep the tires safe. With motorcycles, there are only two small contact patches for the rider to rely on, so it is extremely important to keep the tires in top condition.
Any tire, no matter how well constructed, may fail in use as a result of punctures, impact damage, improper inflation, overloading, or other conditions resulting from use or misuse. Tire failure may create a risk of property damage, serious personal injury or death. To reduce the risk of tire failure, we strongly recommend you read and follow all safety information contained in this brochure.
It is recommended that riders do a periodic inspection of their tires and have any imbedded objects removed by a qualified service person. Serious personal injury or death may result from a tire failure. Many tire failures are preceded by vibration, bumps, bulges or irregular wear. If a vibration occurs while riding your motorcycle, or you notice a bump, bulge or irregular wear, have your tires and motorcycle evaluated by a qualified service person.
It is not often that a properly maintained tire will “blow out” while you are riding. More commonly if air is lost, it will be gradual. If you do experience a blow out or sudden tire failure, the following information should be helpful: When the failure occurs, slowly decrease the amount of throttle, hold the handlebars firmly, and steer to maintain your lane position. Once the motorcycle has slowed and is fully under control, apply the brakes gently. Gradually pull over to the shoulder and come to a stop.
Motorcycle tire inflation and contact patch area
Always keep the motorcycle manufacturer’s recommended air pressure in both tires. This is an important requirement for tire safety and mileage. Your motorcycle owner’s manual will tell you the recommended cold inflation pressure. On some motorcycles, the recommended front and rear tire pressures will be different. The pressures stamped on the sidewall of the tire are only for maximum loads. On some occasions, these pressures will also be the manufacturers recommended settings as well.
Riding on tires with too little air pressure is dangerous. The tires will build excessive heat. This can cause a sudden tire failure that could lead to serious personal injury or death.
Underinflation may also:
-Damage the tire leading to tire failure
-Adversely affect vehicle cornering
-Reduce tire life
-Increase fuel consumption
Riding on tires with too much air can be dangerous. The tires are more likely to be cut, punctured, or broken by sudden impact. Serious personal injury or death could result. Do not exceed the pressure indicated on the tire sidewall. Consult your owner’s manual for the recommended inflation and other tire information.
Never inflate a tire unless it is secured to the motorcycle or a tire-mounting machine. Inflating an unsecured tire is dangerous. If it bursts, it could be hurled into the air with explosive force resulting in serious personal injury or death.
Valve Stems, Cores & Caps
Old or damaged valve stems and cores may cause air loss. Replace them when mounting new tires. Use caps (finger tight) on the valve stems to keep dust, dirt and moisture away from the valve.
Checking Tire Inflation
-Check your tire air pressure at least once a week and before long trips. Be sure to use an accurate pressure gauge.
-Check your air pressure when the tires are “cold.” The tires are “cold” when your motorcycle has been ridden less than a mile at moderate speed or after being stopped for three or more hours.
-If you must add air when your tires are hot, add four pounds per square inch (4 psi)(28 kPa) above the recommended cold inflation pressure. Recheck the inflation pressure when the tire is cold.
-Never release air from a hot tire in order to reach the recommended cold tire pressure. -Normal riding causes tires to run hotter and inflation pressure to increase. If you release air when your tires are hot, you may dangerously under inflate your tires.
-If your tires lose more than two pounds per square inch (2 psi)(14 kPa) per month, the tire, the valve, or wheel may be damaged. Consult your local dealer for an inspection.
-Use valve caps to keep valve cores clean, clear of debris and to help guard against air leakage.
In order for your new tire(s) to provide optimum performance, tires should be ridden very cautiously for the first 100 miles in order for the tread surface to be “Scuffed-In” and work properly. Directly after new tires are mounted, sudden acceleration, maximum braking and hard cornering must be avoided. This will allow the rider to adjust to the “Feel” and handling characteristics of the new tire and for the new tire to be “Scuffed-In” correctly in order to achieve optimum grip level.
Riding your motorcycle in an overloaded condition is dangerous. Overloading causes excessive heat to build up in your tires. This can lead to sudden tire failure and serious personal injury or death while the tire is overloaded or at some later date.
Consult your motorcycle owner’s manual for the motorcycle load limits and proper tire inflation that applies to your motorcycle and tires.
Never exceed the maximum load rating stamped on the tire sidewall of your tire or the maximum vehicle load rating, whichever is less. Before a trip, determine the total weight of luggage, equipment, and rider(s) to be added to your vehicle.
Never exceed the accessory restrictions and motorcycle load capacity found in the owner’s manual, or the maximum load molded on the sidewall of the tire.
Pulling trailers behind your motorcycle is not recommended by Bridgestone/Firestone as trailers may contribute to motorcycle instability and overload.
Riding on damaged tires is dangerous. A damaged tire can suddenly fail causing serious personal injury or death. Have your tires regularly inspected by your local dealer for damage.
Spotting Damaged Tires
After striking anything unusual in the roadway, ask your local dealer to demount the tire and inspect it for damage. A tire may not have visible signs of damage on the tire surface. Yet, the tire may suddenly fail without warning, a day, a week, or even months later.
Inspect your tires for cuts, cracks, splits or bruises in the tread and sidewall areas. Bumps or bulges may indicate a separation within the tire body. Have your tire inspected by a qualified tire service person. It may be necessary to have it removed from the wheel for a complete inspection.
Inspect your tires for adequate tread depth. When the tire is worn to the built-in indicators at 1/32nd inch (0.8 millimeters) or less tread groove depth, or the tire cord or fabric is exposed, the tire is dangerously worn and must be replaced immediately.
Inspect your tires for uneven wear. Wear on one side of the tread or flat spots in the tread may indicate a problem with the tire or vehicle. Consult your local dealer.
Inspect your rims also. If you have a bent or cracked rim, it must be replaced.
Minimum Tread Depth
Excessively worn tires are more susceptible to penetrations and road hazards. Always remove a tire from service once the wear reaches the tread wear indicator bars (indicating 1/32 of an inch of tread depth) located in the grooves of the tire.
Riding on an improperly repaired tire is dangerous. An improper repair can cause further damage to the tire. It may suddenly fail, causing serious personal injury or death. To be safe, go to your local dealer for proper tire repairs.
Before having a tire repaired, tell your local dealer if you have used an aerosol fixer to inflate/ seal the tire. Aerosol fixers could contain a highly volatile gas. Always remove the valve core outdoors, away from sources of excessive heat, flame, or sparks and completely deflate the tire before removing it from the rim for repair.
-Never repair a tire with less than 1/32nd inch (0.8 millimeters) tread remaining. At this tread depth, the tire is worn out and must be replaced.
-Never repair a tire with a puncture larger than 1/4 inch (6.4 millimeters) in diameter. Such tires cannot be properly repaired and must be replaced.
-Repairs of all tires (radial and non-radial) must be of the plug and inside patch type. Using plugs alone on any type of tire is not a safe repair.
-Never repair a tire with a puncture or other damage outside the tread area. Such tires cannot be properly repaired and must be replaced.
-Any tire repair done without removing the tire from the rim is improper.
-Tubes, like tires, should be repaired only by a qualified tire service person.
-Never use a tube as a substitute for a proper repair.
A tire’s speed rating is void if the tire is repaired, retreaded, damaged or abused, or otherwise altered from its original condition. Thereafter, it should be treated as a non-speed-rated tire.
Speed should not exceed 50 mph (80kph) in the first 24 hours after a repair is made and the repaired tire should never be used at speeds above 80 mph (128 kph).
Removing and Replacing Tires on Rims (Tire Mounting)
Always stand well clear of any tire mounting operation. This is especially important when the service operator inflates the tire. If the tire has been improperly mounted, it may burst with explosive force causing serious personal injury or death.
Removing and replacing tires on rims can be dangerous. Attempting to mount tires with improper tools or procedures may result in a tire explosion causing serious personal injury or death. This is a job for your local dealer or other qualified tire service location only.
Serious personal injury or death can result from:
-Failure to select the proper tire and rim. The tire must match the width and diameter requirements of the rim. For example, when mounting 16-inch diameter tires, use only 16-inch diameter rims.
-Failure to inspect both the tire and rim. The rim must be free of cracks, dents, chips, and rust. -The tire must be free of bead damage, cuts, and punctures.
-Exceeding the maximum bead seating pressure. The tire service person must never inflate a tire beyond 40 pounds per square inch (psi)(276kPa) to seat the beads. Be absolutely certain beads are fully seated before adjusting inflation pressure to the level recommended for vehicle operation.
NEVER MOUNT PASSENGER CAR TIRES ON MOTORCYCLE RIMS.
Mount only “tubeless” tires on “tubeless” rims when the rim manufacturer recommends this fitment. Some rims require tubes. A “tubeless” tire must be installed on a “tube type” rim when the appropriate tube is inserted.
Do not install non-radial tubes in radial tires. Insure that the tube marking matches the radial tire marking before installation to rims that require tubes.
A new valve must be installed on the rim each time a worn out motorcycle tire is replaced.
Never put flammable substances in tire/rim assemblies at any time. Never put any flammable substance into a tire/ rim assembly and attempt to ignite to seat the beads.
It is extremely important that the proper size of rim is used for your tires. Be sure to match your tire size to the size allowed on the rim. Improper rim width may affect handling and stability. Consult the sizing information of the tires you want to install for rim width allowances. Be sure that there is proper clearance between the tire and swingarm and any fender areas.
Tire & Wheel Balance
To avoid vibration and accelerated tire wear, it is essential to balance the tire & wheel assembly before use and each time the tire is removed or replaced on the rim. Also, check the rim for any imperfections as they could affect the overall balance.
Tire Size Selection
All motorcycles should be equipped with the tire size specified by the motorcycle manufacturer as found in the owner’s manual or manufacturer’s website. Be sure to equip the bike with radial tires only when they are required by the bike manufacturer.
Front and Rear Tire Matching
For optimum performance, it is very important to correctly match your front and rear tires. Riding your motorcycle with an improper mix of radial construction tires with bias or bias-belted construction tires is dangerous. Your motorcycle’s handling characteristics can be seriously affected. You could have an accident resulting in serious personal injury or death. Consult your owner’s manual or your local dealer, for the proper tire replacement.
-Mount tires marked ” Front Wheel” on front positions only and tires marked “Rear Positions” on rear positions only.
-Never mix Radial construction tires with bias or bias-belted construction tires.
-Some motorcycles may be equipped with Radial tires. Consult the motorcycle manufacturer before equipping replacement Radial tires to insure the proper specification and combination for your motorcycle.
-A new front tire equipped on a motorcycle with a worn rear tire may cause instability.
When fitting a new tire on a rim requiring a tube, a new tube should be fitted at the same time. Old tubes may become stretched and cause a crease which could make the tube fail. Check the size markings on the tube to ensure the tire size appears on the tube. Do not fit tubes in radial motorcycle tires, nor fit radial tires on rims requiring tubes, unless it is specified by the tire manufacturer.
Riding at high speed is dangerous, and can cause a motorcycle accident, including serious personal injury or death.
Regardless of the speed and handling capabilities of your motorcycle and its tires, a loss of control can result from exceeding the maximum speed:
(a) allowed by law or
(b) warranted by traffic, weather, vehicle, or road conditions. High-speed riding should be left to trained professionals operating under controlled conditions.
No tire, regardless of its design or speed rating, has unlimited capacity for speed, and a sudden tire failure can occur if its limits are exceeded.
Never use race only tires on public roads. Race tires are constructed in such a way that they are very unstable under normal street riding conditions. These tires also require higher operating temperatures for proper performance. These temperatures cannot be obtained within legal speed limits.
Do not use a tire on the road that has been subjected to motorcycle dynamometer testing. The stress from this process may result in tread compound degradation and possible tire failure.
Tire Speed Ratings
Some tires bear a letter “speed rating” designation indicating the tire’s design speed capability. This speed rating system is intended to allow you to compare the speed capabilities of tires.
When purchasing or replacing speed-rated tires, make sure to:
Use the rankings in the chart below to compare the speed ratings of all the tires, and
follow the motorcycle manufacturer’s recommendations, if any, concerning the use of speed-rated tires.
To avoid reducing the speed capability of the motorcycle, replace a speed-rated tire only with another tire having at least the same speed rating. Remember, it’s the “top speed” of the “slowest” tire on the vehicle, which cannot be exceeded without risk of tire failure. The letter symbols and corresponding design speeds are: Speed-Rating Symbol Speed Category*
* In laboratory tests that relate directly to highway speeds.
Reminder: Actual tire speed and performance capability depends on factors such as inflation pressure, load, tire condition, wear and driving conditions.
** Although no upper limit speed is specified here, the indicated tires nonetheless have limited rated speed capability. Call 1-800-367-3872 for a referral for more technical information.
*** Any tire with a speed capability above 149 mph (240 kph) can, at the tire manufacturer’s option, include a “Z” in the size designation (120/70ZR17). If a service description IS NOT included, the tire manufacturer must be consulted for the maximum speed capability. If a service description is included with the size description, the speed capability is limited by the speed symbol in the service description.
Spinning a tire to remove a motorcycle stuck in mud, ice, snow, or wet grass can be dangerous. A tire spinning at a speedometer reading above 35 miles per hour (55 km/h) can in a matter of seconds reach a speed capable of disintegrating a tire with explosive force. Under some conditions, a tire may be spinning at a speed twice that shown on the speedometer. This could cause serious personal injury or death to a bystander or passenger and extensive motorcycle damage. Never spin a tire above a speedometer reading of 35 mph (55 km/h).
Wheel Spokes / Wire Wheels
Regularly inspect the spokes of your motorcycle wheels. Broken or loose spokes may cause wheel wobble, which can lead to instability and premature tire wear. Check rim tape condition. A protruding spoke can damage a tube and cause a tire puncture.
Tire and/or Vehicle Storage
Tires and/or vehicles should be stored indoors in a cool dry place where water cannot collect inside the tires. The tires and or vehicles should be placed away from electric generators and motors and sources of heat such as hot pipes. Storage surfaces should be clean and free of grease, gasoline, or other substances, which can deteriorate the rubber. Improper storage can damage your tires in ways that may not be visible and can lead to serious personal injury or death.
Oil, Grease and Gasoline
These items can deteriorate rubber when exposed to a tire for any length of time. Use a clean, damp cloth to remove these chemicals from the tire.
Use a mild soap solution to clean sidewalls, white stripes or raised white lettering, and then rinse off with plain water. Never apply any other materials, cleaners or dressings to enhance sidewall appearance. These items may degrade the rubber and remove inherent ozone cracking and weather checking resistance.
MOTORCYCLE TIRE CONVERSION CHARTS
What do these terms mean?
Example: 130/90-16 67 H
130 = Section width of the tire (130 mm)
90 = Aspect ratio (90%) (Section height divided by Section width as a percentage)
16 = Rim diameter (inches)
67 = Load rating (A numerical code which corresponds to the total laod carrying capacity at the speed indicated by the speed symbol)
H = Speed rating (see chart)
Example: MT90-16 LOAD RANGE B
M = Motorcycle code
T = Tire width code
90 = Aspect ratio (90%)
16 = Rim diameter (inches)
LOAD RANGE B = Load range
Example: 5.00 H 16 4PR
5.00 = Section width (inches)
H = Speed rating
16 = Rim diameter
4PR = Casing strength (ply rating)
Tire Sidewall Markings
TOP 10 TIRE TIPS
A neglected tire can be a deadly one. The simplest and most important thing you can do for your tires’ health and your safety is keep them, inflated to the designated pressure.
1. Air It Out: Check tire pressure every chance you get. There’s probably no simpler procedure that’s more important and more ignored by bikers of every stripe. The air, not the carcass, supports the bike, and underinflation is a tire’s number one enemy. (Make sure the tires are cool when you take the reading.) For a better tractrion in wet conditions, increase pressures by about 10 percent. Unsure of what the pressure is supposed to be? Look for a sticker somewhere on the bike. It is also probably on the VIN (serial number) plate hear the steering head with the gross vehicle weight rating (GVWR) and gross axle weight ratings (GAWR) information.
2. Step in Line: Pay close attention to alignment–shaft drive bikes have no adjustment, but if you have a chain or belt, check the position of your tires. Proper alignment ensures better handling and longer wear.
3. Steady, Now: Although it primarily affects handling, improper balance can also shorten a tire’s life. Check it after 500 or 1000 miles of use.
4. Top It Off: The valve stem cap should be securely fastened on the stem, because it’s an important part of your tire’s sealing system. It’ll give you extra security at high speeds, when centrifugal force can conspire to open the valve inside the stem.
5. Soap It Up: Most tire manufacturers recommend that the only substance used to keep rubber shiny should be good old soap and water. Many alleged protectants actually promote premature cracking and finish deterioration. Make sure you wipe off any lube, brake fluid or gas promptly, too.
6. Look Before You Crank: Before you saddle up, take a moment to visually inspect your tires. We can’t tell you how many times we’ve pulled out screws or nails before a ride, thus preventing almost certain tire failure. Once you’re on the road, it’ll be too late.
7. Stay Smooth: This is common sense–avoid potholes and sharp objects on the road that can compromise your tire’s integrity. The same goes for curbs.
8. Don’t Mix and Match: Never run two tires of differing construction. We can’t stress this enough, and this rule applies to bias-plies vs. radials as well as tubeless and tube-type tires–even bias-ply vs. bias-belted tires. The results can be disastrous.
9. Scuff ‘Em Up: Optimal grip is obtained only after the tread surface has been ridden on, so go into those first few twisties with a bit of caution. The suggested break-in distance is usually 200 or so miles. After that, check the tire’s pressure again!
10. Don’t Scrimp: If you replace your tires, make sure you replace the tubes, too. Some manufacturers even recommend that you change both tires at the same time, even if they wear differently.
Special Thanks to Bridgestone
– Total Motorcycle Tire/Tyre Maintenance Guide
– Tire Information Handbook (PDF)