How to choose the right motorcycle tire

May 01, 2014

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Tires are perhaps the most important component on any motorcycle. They are the key to performance, comfort and safety. Without proper tires and routine inspection and maintenance, our motorcycles aren’t going anywhere. Use this tire guide to learn some of the basics about how motorcycle tires function, their construction and how to choose the right tire for your bike.

New Tread

Your engine performance and chassis are only as good as the tires that put the power to the ground and keep you planted in those corners. No matter the rider or riding style, from heavy baggers to ultra-fast liter bikes, the correct tire is literally what keeps the good times rollin’.
Whether you are replacing a set of worn-out tires or upgrading to improve performance, it is important to know what the specifications of the tires are for your specific bike and how to match the specifications against those of the tires you are considering.

ANATOMY OF A TIRE

Out of the gate we’ll be getting familiar with the basic parts that make up a tire.

Tread: The most obvious part of the tire people see is the tread, this is where rubber meets the road. You’ll find a variety of tread patterns depending on the intended use for that tire.
Carcass: This is the backbone of the tire that lies underneath the tread. Essentially, the carcass is made of steel or fiber cords that run from bead to bead. Every tire is either a bias ply or radial ply, which is a MAJOR distinction. Bias plies are laid at an angle (bias) in a direction, whereas radial plies are laid directly from side to side. We will discuss the benefits of each a bit later.
Bead: The bead is where the tire mounts to the wheel. Multiple steel cords are placed in these areas to ensure a snug fit against the wheel and no leakage in a tubeless tire.
Sidewall: This is where the vital tire information is displayed, however the sidewall is much more important than just an indicator. Virtually all the load support and much of the handling is determined by the sidewall design.

Bias or Radial

As motorcycle engines and chassis have advanced, so have tires. Traditionally, motorcycle tires were bias ply, which means the carcass was made up of body cords at an angle directionally. Flash forward to the present, and you’ll see a radial design in many tires, where plies are laid from bead to bead instead. This leads to many advantages:

• Heat dissipation: Radial tires displace heat better, which increase longevity and improved wear
• Sidewall Flexibility: By construction, radial tires sidewalls are not stiff as bias-ply tires. This allows the sidewalls to contour to the road better, improving surface area to the section or tread.

Bias-ply tires are still sticking around, but for good reason. Due to the stiffer sidewalls, bias-ply tires come standard on many heavy cruisers and touring bikes. The lack of flex works well for bikes designed to carry passengers and/or luggage.

Now that we’re familiar with the tire construction, the next step is learning how to decode the sidewall information. Most of what you need to know is molded right into the tire’s sidewall in either metric or alphanumeric. Let’s dissect a typical metric sidewall designation example: 130/90 R 16 67 H

  • The first number refers to the tire width: 130 indicates the tire is 130mm wide at its widest point when installed and ready to ride. This is referred to as “section width.”
  • The second number refers to tire height: 90 indicates the tire’s sidewall aspect ratio; which is 90 percent as tall as measured as it is wide, or 117mm in this example. The lower the aspect ratio, the shorter the sidewall if section width remains unchanged.
  • The Letter designation refers to tire construction: For this example, R stands for radial ply. If the carcass design was bias, it would be indicated as “B”.
  • The third number is the wheel size: 16 indicates the wheel diameter in inches the tire is designed to fit. In this case a 16-inch wheel.
  • The last number refers to the load index: In this case, 67 is the load index designation. In this example 67 informs the consumer that the tire’s maximum load capacity is 661 lbs. (see chart)
  • The last letter refers to the load index: In our case, H is the designated rating, which means the tire is suitable for speeds up to 130 MPH.

Alpha Numeric- MT 90 – 16 Load Range B
Alpha numeric is very similar to metric. The first letter always is M, for “Motorcycle.” However the second letter is important which represents the width or section. Like metric, the number following the section width is the aspect ratio. Like metric again, the next number is wheel size followed by load rating.

Stick With OEM Sizing

Stick With OEM Size Tires

With your new-found understanding on sidewall information, finding a replacement tire can be quite the undertaking. With a seemingly endless amount of options, you might be asking yourself what you’ve gotten yourself into. The best option is actually perhaps the simplest option, sticking with what came stock on your bike. Motorcycles were designed and developed with a specific tire size, so altering the ply style or load rating can be unsafe and not handle properly.

Proper Tire Pressure

Possibly the most overlooked preventative motorcycle maintenance is checking the air pressure. Not only can under or over inflation be unsafe and cause unpredictable handling, millage decreases as well. When your tires are over inflates the middles section tends to wear faster than the sides of the section. When under inflated, the inverse is true, and your sides will wear disproportionality to the middle section.
Here are a few tire pressure tricks to ensure longevity and safety out on the road:

Tire Pressure Gauge

1. Use Suggested Pressure: Always abide to suggested tire pressure indicated on the side wall for proper pressure. If you are going to carry lots of luggage or a passenger, we suggest adding a bit more pressure being sure not to exceed the tire pressure indicated on the sidewall of your tire.
2. Get yourself a good gauge: Cheap $5 gauges found at the checkout counter of a NAPA can be a decent tool to have, but a quality tire pressure gauge will be much more accurate. Tire performance is heavily tied to pressure, and even a few PSI can drastically effect handling. Always check pressure when the tire is cold (not immediately after you get off).
3. Check pressure frequently: Anywhere from daily to weekly will serve you fine. Really, the conditions and amount you ride should dictate how often you check your pressure, but it’s always better to be safe than sorry!

Tube Type Tires


Many bikes come with a tube type tire, and if yours does, it is important to install a fresh new tube with every tire change. Do not try and fit a tubeless tire on a tube type wheel, as the bead will not likely seal properly, which will ultimately leak. Finding the right size tube is a simple procedure if you know your tire size. In metric sizing, tube sizes are indicated as such: 110/90 (where the first number is width and the second number being the aspect). Alpha: MP85 (First letter is always M for “motorcycle”, second letter is the section width, and the number represents aspect ratio).

WHEN TO REPLACE AND HOW TO SPOT A WORN OUT TIRE

It’s tempting to look at your tread and think, “she ain’t bald, there’s tons of tread left on those bad boys.” But in reality, your tires don’t have to bald, to be out of commission. Here are a couple of things to inspect if it’s been a while between fresh hoops:

Tread Depth
Tread depth should not be below 2/32"

1. Tread Depth: To eliminate the guess work, manufactures incorporate wear bars that run across the tread. Once the wear bars are flush with the tread, it’s time to replace. Another easy trick is use the old penny technique. Placing a penny in the tread, if Honest Abe’s head is covered in some degree, your tires likely have some life in them. There should be at least 2/32” of tread in any area.
2. Age: As a rule of thumb, no matter the tread wear, a tire’s active life span should not exceed five years. Some people suggest a tire’s life is done five years after manufactured date, however we feel it’s safe to extend that to 10 years.

Cracking Tires
Look for cracks in the sidewalls & tread

3. Cracking: Like most things, tires are not immune to sunlight, and if your tires have been exposed for long periods of time, you might experience cracking on the tread or along the sidewalls.
4. Cuts and Punctures: Frequently check for any cuts or punctures in your tire.
5. Loosing Pressure: Since you’re checking your pressure frequently, you’ll notice if a tire continues to loose pressure too rapidly. If this is happening, your bead may be worn out and leaking air.

Worn out tire

6. Feeling Odd: Sometimes the best way to spot a worn tire is in your hands. If you notice vibrating, pushing, pulsating or any unnatural sensation when riding, it could be your tires.
7. Under-inflation or over-inflation can lead to uneven wear (mentioned above). You will find excessive wear in the center or sides of the tire if not aired up properly (shown here).

Conclusion

That’s it for our basic motorcycle tire buyer’s guide. Hopefully with the knowledge you’ve gained you can take the right steps towards buying the best tire for your bike and needs! The individual tire pages will have great info on intended and best usage, features and even detailed videos to help you make an informed purchase. Remember to check your tire pressure, let your tires warm up before opening her up, and as always, have fun!

Here is a speed Rating Scale for reference:

Tire CodeMax Speed (MPH)Max Speed (KMH)
L74120
M81130
N87140
P94150
Q100160
R106170
S112180
T118190
U124200
H130210
V149+240
W168+270
Y186300
Z/ZR186+ 

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