You won’t find a motorcycle rider anywhere who wouldn’t agree that wheels and tyres make the biggest difference in how well a bike rides. Everything from the amount of grip that’s available in the corners, to the stopping distance needed to brake in an emergency is determined by two relatively small contact patches, so the rubber on your bike demands reverence and attention.
The fact is, most wheels and tyres are incredibly durable and can deliver thousands of problem-free kilometres of riding when they’re ridden within their tolerances. Competition riding, or riding on exceedingly rough or demanding terrain, however, can easily push even the best wheel and tyre combinations beyond their limits.
Ideally, not only do you need to inspect your wheels and tyres before every ride, but you also need to make sure that you’re using the right combination for both your bike and the type of riding you’re doing. Because if you’re not, not only are you throwing away performance, but you’re also increasing costly wheel and tyre wear which could jeopardize your safety.
New Motorcycle Wheel and Tyre Combination Characteristics
Let’s be honest: with so many different combinations of front and rear motorcycle wheels and tyres to choose from, even professional riders can get lost in the science of how to get the most out of their rolling stock. For the regular rider though, make no mistake: motorcycle manufacturers pour countless hours of research and engineering into optimizing their wheels and tyres before every bike hits the showroom, and altering those combinations afterwards is often a bold adventure into the unknown.
Whether it’s for improved handling while carving mountain roads, or for more bite while skidding through muddy bush tracks, there are three very different, but closely related tyre characteristics that every rider has to come to grips with on their motorcycle wheel and tyre combination:
- Traction.No matter if it’s needed for accelerating, braking, or cornering, this is your tyre’s ability to maintain its grip on any surface, under any condition, or from any angle.
- Load rate.When correctly inflated, this is the maximum weight a single tyre can carry. The combined rating of your front and rear tyres make up your bike’s maximum tyre capacity.
- Tread depth.Depending on surface conditions, your tread depth ensures the maximum amount of rubber from around the circumference of the tyre is firmly in contact with the riding surface at all times.
Australian Design Rules (ADRs) are very specific about the fitting of wheel and tyre combinations on road-certified bikes that aren’t exact-sized showroom replacements, or haven’t been specified by the manufacturer. Their position actually reinforces the reality that splurging on bigger motorbike wheels and tyres doesn’t mean your bike will ride or perform better. In fact, given the effect that a larger, untested combination would have on your bike’s geometry and stability, your ride quality, performance, and even fuel economy would probably suffer dramatically.
Understanding How Motorcycle Tyres Are Coded
Believe it or not, the best way to increase wheel and tyre performance is by concentrating on their composition. Understanding how tyres are coded, however, is the crucial first step in identifying how traction, load rate, and tread depth actually come together.
Regardless of whether you’re looking at dual sport, GP sport, or full touring tyres, you can always expect to find coded specification information stamped on the sidewall. This millimetre-specified data is arranged in a numerical xxx/xxx – xx format, and it displays:
- Tyre width.This is the tyre’s 3-digit width at its widest point from sidewall to sidewall, and is also known as its sectional width.
- Tyre aspect.This is the 2- or 3-digit height of the tyre’s sidewall, which is expressed as a percentage of its width.
- Tyre diameter.This is the 2-digit diameter of the wheel the tyre is designed to be fitted onto.
Alphabetically coded tyre data is also used to define tyre characteristics that include:
- Tyre speed rating.Ordinarily from “P” (max 150kph) to “Z” (above 240kph).
- Tyre carcass fabric.“B” for belted, “D” for diagonal, and “R” for radial.
- Tyre load/speed rating.An alphanumerical designation of the tyre’s maximum speed at a given weight capacity.
Suffice it to say, it’s almost impossible to change any dimensional aspect of a showroom wheel and tyre combination without the need to change every other aspect of it, and that’s precisely what you want to avoid doing to ensure that your bike stays ADR compliant. This is where progress in tyre composition is making big performance differences without going beyond the manufacturer’s intended specifications.
Dual Compound Tyres Have the Characteristics You Want
Now more than ever, riders are looking beyond larger tyres and concentrating on the performance gains that innovative new dual compound tyres and tread designs have to offer. These compositions don’t have any effect on a bike’s suspension, won’t interfere with any other parts of the chassis, and don’t diminish overall safety, making it possible to legally fit wheel and tyre combinations that are better suited for more tightly defined riding styles.
Dual compound tyres come in a variety of sizes for both front and rear fitments, and use a range of soft rubber compounds throughout the shoulders that simultaneously enhance stability and reliability. This allows them to maintain a uniform contact patch that delivers:
- Superior tyre grip in curves and cornering;
- Greater wear resistance on straights; and,
- Improved tread design for increased water dispersal.
The increased adhesion, durability, and tread surfacing of dual compound tyres make it possible to improve performance across the board without altering your bike’s geometry or handling in any way. You won’t find a better wheel and tyre solution that performs better or lasts longer.
The Final Word
At the end of the day, every rider wants better than showroom performance out of their bike. And fortunately, it’s possible for a new wheel and tyre combination to yield the exact type of performance benefit you want while still allowing your bike to stay ADR compliant.
Upgrading your front and rear motorcycle wheels and tyres to a dual compound composition is the way to keep showroom size and specification rubber on your bike, but with the improved ride quality, performance, and reliability that you want.