A Guide to Motorcycle Tires: Part 1

Ahoy there, two or three-wheeled fellows, and welcome to a new piece that will help some of you understand some more details in the biking world a tad better, and hopefully make your ideas better, smoother and safer.
This week's special is tires. Quite a few riders realize the true importance of the rubber in the whole “cycling equation” – since that small patch of vulcanized latex is the only thing that keeps the bike in contact with the ground, it definitely deserves more attention.

Good Rubber Makes a Good Ride

Automotive tires have gone a long way since their debut at the end of the 19th century. Even though the first inflatable tire is attributed to John Boyd Dunlop, official credits for the modern tires go to Charles Goodyear and Robert William Thomson. And with the development of synthetic rubber during the 1920's, a wider and more complex range of tires has become possible, covering from bicycles and motorbikes to cars, trucks and all sorts of heavy-duty machinery.

From its debut, the rubber automotive tire has remained the best way to maintain contact between the vehicles and the roads, with no better alternative so far. While granting the much-needed grip, tires can also affect the way you ride in terms of speed, bike handling and cornering, or shock absorption when traveling on rougher roads.

How all these variables change according to the tire and being able to choose best rubber for a certain purpose are mandatory lessons a rider should learn. It's no rocket science but it is no child's play, either; while choosing the right tires can improve your motorcycle experience, installing the inappropriate ones might get you in trouble.

Why and when

First of all, we have to clarify that there are a lot of elements making a bike run smooth, no matter if we're dreaming about an all-asphalt trip on Europe's highways, fun in puddles of mud or zooming at high speed on race tracks. For absolutely each scenario, a bike's peak performance is a combination between what the engine, preparation and tuning, pilot skills, road/ weather conditions AND tires can deliver.

It would be technically impossible to rank the above. Each element has its own importance and can play the leading role in different scenarios, but one thing is beyond any shadow of a doubt: if we agree that a pilot error is the number one cause for a crash, riding with bad or inappropriate tires comes next.

Aside from simply getting worn because of high mileage, and aggressive riding style or burnouts, tires do get old. There are a lot of things that change inside a motorcycle tire as years and multiple heat cycles pass by; the initial properties of the rubber also wear out and can make riding hazardous.

That's why changing the tires on your bike is no task to be taken lightly – it must be done as soon as you're reaching the wear limit established by the manufacturer, or notice various bumps or cracks in the rubber. Even with low mileage, a 5 years-old tire should be changed by all means, as it no longer sports the same features like it did when new.
Taking a bit of time to delve in the world of motorcycle tires may seem boring and un-productive for some of you, understanding how tires really are and what they can do for the ride and rider will prove to be quite valuable knowledge in the end: it will spare you money and time and it will also help you get the best from your bike.

They're so few and yet so many

Each bike has been designed with a specific type of tires in mind and this is one of the most important things to be considered. The guys who have engineered that motorcycle are most likely the ones with the most extensive knowledge base on that particular model and their decision to go with certain tires is well founded. Of course, there is some “slack” when it comes to what that manufacturer specifies to some spare parts and straying too far from the “well-trodden path” is not advisable.

Even though at the first glance it may seem like there are rather few options when having to choose the tires for your bike, taking a closer look at the product range of various manufacturers will most likely put the newbie in difficulty. Aside from the inherent differences between the front and rear tires (since they serve completely different purposes), tire properties and performance can vary quite a lot depending on construction, bias, material, tread design, and so on.

Each model comes with its pros and cons – learning to match your actual needs and riding style to what a specific set of tires can offer when installed on your bike is almost an art, but mastering it provides safer and more enjoyable rides.

You should note that there are a lot of specs that vary when it comes to tires and each of these values affects the way your bike will behave. Data coming from word of mouth, advice from experienced pilots and by all means – manufacturer spec sheets are to be combined if you're trying to make the best choice.

Different types of bikes have their own range of suitable tires and no one would have motocross tires loaded on sport bikes. Slight variations such as installing street tires on a dual sport bike and thus having it biased towards the supermoto side are acceptable, but knowing what you want to do with your wheels is essential.

You'll even notice that there are multiple types of tires for the same purpose, but addressing various riding styles and life expectancy, as well as wet/ dry bias. You really do have a lot of tires to choose from if you are willing and there's definitely so much more than choosing the right size for your ride.

Front versus rear

Bikes differ a lot from cars and other vehicles as far as tires are concerned and this is because the front and rear wheels have different functions.

While the front one deals mostly with steering and setting the motorcycle on the desired trajectory as well as braking, the rear wheel is responsible for transferring power from the chain/ shaft/ belt drive system and accelerating. The rear wheel is also the one on which the bulk of a bike's weight sits and is carried forward, and this also impacts the tire construction dramatically.

As far as sizing is concerned, you'll either be riding the most common type of bike with the rear wheel smaller in diameter than the front one, or a much rarer kind with the same size for both wheels. The larger the front wheel, the easier passing over obstacles or holes in the pavement/ ground will be.

Now, the size of the tires you'll install is impossible to change as it depends on the size of the rims. Nevertheless, you can choose “taller” tires, with a bigger arch and higher sidewalls, if this serves your intended purpose. Remember that the overall height of the bike will also vary as you switch between two tires with different heights and you should make sure your feet still get a good grip on the ground when bigger tires are in place.

It is generally advisable to install a set of tires with the same sidewall sizing. Namely, if you go for a “tall” rear tire, you should get its pair for the front. That's why manufacturers of common tires will most often offer them in pairs, providing the same performance expectancy for both rear and front tires.

Those who are planning to take their bikes in places with special conditions could choose different types of tires for front and back, if needed. However, the perfect combinations between different types are rather rare; in case you plan to take your bike in places with – let's say bumpy roads with gravel – the wisest thing would be changing both front and rear tires with the appropriate ones.

A word on tire age

Rubber is a wonderful material and choosing the right recipe for your bike, your riding style and roads you're about to travel on will make your trip faster and safer, more economical and comfortable, an altogether more pleasurable experience.
Nevertheless, rubber tires wear out and their performance can drop at a fast pace once you're getting closer to the end of their life as specced by the manufacturer. Even more, if riding with excessively worn or old tires, they can become a true hazard for both motorcyclist and others on the road.

Explosions, tears and all sorts of mishaps are small wonder with “dead” tires, but the first noticeable change will negatively affect grip and stability. The tread patterns you see on tires respond to various needs, and this is why a racing tire made for wet tracks looks so different when compared to a motocross one. In both cases, the tire will perform as expected until either worn out or aged beyond the specs.

As years pass by, rubber suffers some chemical changes, and the tire gradually loses its elasticity and this leads to poorer grip, less traction, being more prone to slipping. This happens with both natural and synthetic rubber and that's why each tire comes with the year of manufacture stamped on it. For example, a tire manufactured in 2012 will have the DOT12 (or similar) mark on it.

As a rule of thumb, it's better to use tires as new as you can afford; while there are millions of tires being manufactured each year, most of those one could find in the retailers' warehouses are 1-2 years old already, with a small fraction of the stocks comprising even tires made 4 years ago.

You'll notice some small cracks in your older tires; most of them are not to be dreaded, they're there just to remind you that the tire is beginning to grow old. Of course, in case you see the cracks getting bigger, you should prepare for a change as soon as possible.

Less experienced riders should know that these cracks will eventually appear even as the bike is left in the garage for a long time: rubber does get older, whether you use it or not. Adding in the worse traction caused by the hardening rubber makes your bike less safer and calls for a trip to the tire shop.

Please check back with us in the future, for the next part of this guide dedicated to tires.
If you liked the article, please follow us:  Google News icon Google News Youtube Instagram

Would you like AUTOEVOLUTION to send you notifications?

You will only receive our top stories