Honestly, I am just like most other motorcycle riders. I hate to replace tires unless it’s needed. But the fact is… worn-out tires are a safety hazard!
Are you waiting until your tires turn as bald as a coot before replacing them? Too bad.
You need to live longer to ride more. No questions about that!
Here’s a question though. When is it time to replace motorcycle tires?
One of the easiest ways to know is by reading the tire wear bars or tire wear indicators.
Let me show you how.
The Art of Motorcycle Tire Tread Pattern Design
Now, tread patterns on a motorcycle tire may look complex but they aren’t so mysterious after all.
(Nothing in the league of something like a mosquitoes’ blood preferences)
There’s a lot of research and field testing that goes into the engineering of tread patterns. Treads are considered as blocks based on the contact patch with the ground.
Each patch has a leading edge and a trailing edge. Now think of determining the forces on these edges as they go round and round at a variety of lean angles. Not to forget, the speed variations.
Sounds complex? There’s more.
You need to consider the tread deformation due to the weight of the bike and the load it’s carrying. The torque produced by the engine while carrying the load will also affect the tread design.
(Can we move on, please? I love a simple life.)
The main functions of the tread are the following:
- They maximize the traction while you’re riding on a variety of surfaces and in varying weather conditions.
- Balances the flexibility of the tire compound and strength to provide the best mileage.
- Helps owners to know when to replace the tire.
- Tires without tread patterns are not DOT legal. You can’t use smooth tires on the streets in most states.
- Lastly, the treads also serve an artistic purpose by making the tires look good. Let’s not forget they are one of the most visible parts of your bike. So they need to look cool.
The fact is, designers in a studio and engineers work hand in hand to create the final tread patterns. Feedback from veteran riders is also taken before finalizing.
It all comes down to this.
As the tread wears down, tire performance is affected in a major way. With the reduction in tread thickness, the tread channels can’t divert water. This results in the reduction of wet traction.
Quite simply, it’s NOT safe to ride on worn-out tires.
Just imagine, while riding your life depends on the two small contact patches of the front and rear tires. Any loss in tire performance can be a big safety hazard.
What Are Wear Bars On A Motorcycle Tire?
Look closely and you’ll find multiple sections in a tread block. The raised sections of a tread are called the ribs. Also, there are raised sections called the tread blocks that form the contact patch with the road.
In addition, there are grooves. These are channels that run over the tire surface along with the tread pattern. Tread depth is the vertical distance between the bottom of a groove to the top of the rubber.
The tread wear bars are small raised sections within a groove. They are placed evenly across the tire circumference.
Anytime one or more of these bars are in level with the top of the tread you need to replace the tire. Don’t wait till the tread wears further and the wear bars start making contact with the road surface.
And if you frequently ride in wet conditions, it’s best not to wait ’til the wear bar levels match with the tire surface.
💡 Just like tire speed rating, tire manufacturers have their own recommendations about minimum acceptable tread depth based on the tire design. Different tire types have different tread depths and service lives. Generally, tire change is recommended when the tread wears down to 2/32”.
Let’s consider a new tire with 10/32″ of tread depth needs to be replaced when the tread depth reaches 2/32″. That means the usable tread depth is 8/32″.
If the tread depth of the same tire after a few years of use is 4/32″, we can say that the tire is 50% worn.
Besides, most states have a legal tire tread depth requirement, which is 2/32”. So you can’t drive with anything less than the specified limits.
Make sure to follow the manufacturer’s recommendations on this.
One more thing…
Not all brands may use tread wear indicators. Some tires have the words TWI marked on them. If these words are flush with the top surface, change the tire.
Now, there are various factors that affect the rate of wear. If you’re a frequent tourer, chances are, the treads will wear out faster. This is due to multiple reasons:
- Extra weight that you carry in the form of travel gear.
- Increase mileage
- Extensive freeway riding at higher average speeds.
What about uneven tread wear?
That can happen due to reasons like tire under-inflation or over-inflation. Wheel misalignment can also be a major reason. In that case, it’s best to get the motorcycle checked by a mechanic.
In fact, in case of uneven wear, a technician might recommend a tire change even before the tread depth reaches the minimum requirement.
How To Read A Motorcycle Tire Wear Indicator
Did you know that there’s a simple way to check the condition of your tire’s tread?
All you have to do is run your finger horizontally over the tire wear bars. If the wear bar feels even as the thread, that means you need to get new tires and replace them as soon as… NOW.
(A bit exaggerated, but better safe than sorry!)
To take more accurate measurements, use a tread depth gauge that’s readily available in most automotive stores. Other than that you can also use a ruler with inch measurement. Put one end of the ruler inside the groove and measure the level of the tread.
Perhaps you can’t find the wear bars on the tire. Time for the good old penny test to check tire tread wear. It’s not as precise, but effective.
Take a penny and place it inside a groove with Lincoln’s head upside down. If the top of the head isn’t visible, there’s some tread left in the tire. If the entire tread is visible, the tire is toast.
Frequently Asked Questions
Do motorcycle tires have wear bars?
Yes, motorcycle tires have wear bars. Wear bars are located inside the grooves on the surface of the tire.
How many wear bars on tires?
Wear bars are distributed over the entire tire surface. The number of bars will vary depending on the design and size of the tire.
Is 80 percent tire tread good?
No, it isn’t. 80 percent tire life means it’s time to change the tires. Most motorcycle tires have a tread depth of 10/32″. 80 percent tire wear means the treads have reached 2/32”, which is the usually recommended minimum usable tread depth.