Effects of Tire Size on ATV Performance

March 11th, 2019 by

Whether you own an all-terrain vehicle (ATV) for recreational or professional purposes, it’s good to know some technical stuff. Although knowing about engine maintenance is useful, we tend to be a bit less informed about ATV tires. In this article, we discuss ATV-tires in detail. We also focus on the effects of tire size on ATV performance.


Tire Size and ATV Performance

The adage “bigger is better” doesn’t always hold, particularly regarding ATV tires. There are exceptional circumstances such as deep mud, heavy snow or rugged terrain where the extra ground clearance is helpful. However, on a day-to-day basis, the benefit you get is purely cosmetic. If you use a larger tire, you should ensure that your ATV can withstand the stress of larger tires. You may even have to make some modifications to your vehicle to accommodate heavier tires.

Oversize ATV tires are usually significantly heavier than stock tires. This factor is a significant one to consider, as extra stress gets exerted on various components. The result is that the extra tire height and weight can have a bearing on vehicle performance. Let’s consider the way tire size can affect various components of your ATV:


Gearing/Low-End Torque/Clutch

With taller tires, the gear ratio gets increased. A larger ATV tire will result in a larger rotating mass from the increase in weight. The combination of both results in a reduction of low-end torque. Your engine will need to make an extra effort to get the wheels moving from a stationary position. You may not be able to spin tires in mud as effectively, either.

To fix these issues, you would have to reduce gears so that the wheels spin faster. Alternatively, you can install a clutch kit. Clutch kits help to rev the engine to a higher degree before engaging. This addition provides a better starting grip on the ATV tires. Now you will get a better grip while traveling through thick mud. However, the top speed of your ATV will now reduce. You need to decide between high-traction in mud or higher cruising speeds, but you can’t have both.


Low-End Acceleration

With a heavier tire, you get a larger rotating mass. Your heels will not turn fast from a stationary position. This modification means that if you need to make a quick start as in a race, you will be at a disadvantage. In this case,  you may have to do the reverse, that is, use smaller tires than stock tires. You will find a smaller tire easier to turn, and there is also a reduction in gearing to accelerate fast. Your vehicle will suffer a decline in top-end speed.


Suspension and Drivetrain Stress

The standard drivetrain and suspension components of ATVs will not usually take the extra stress of larger size tires. Larger diameter tires increase the weight of these components and increase the frequency of maintenance and repairs. A good remedy is to install heavy duty axles, CV joints, extra shocks, and similar heavy-duty components.


Shifting Center of Gravity/Poor Handling

You install bigger tires to increase your ground clearance. With the raising of the chassis, the center of gravity of your ATV will also get raised. The result is that the vehicle becomes more unstable while making sharp turns. The turning radius also gets reduced as a result of increased height and weight of the tires increasing steering effort. It becomes more difficult to steer your ATV. So, the trail riding capabilities of your ATV get negatively impacted with larger tires.


Check Your Manufacturer’s Warranty

Due to the possible issues that may occur as a result of changing tire size, manufacturers place certain restrictions. Although a slight increase in tire size may be allowed, check the warranty terms. Each dealer will have a different set of terms and conditions. Ensure that you are within permissible limits with any modifications that you propose to do. Also, check if the new tires are allowed as per the warranty terms. Of course, if your vehicle has crossed the warranty period, then the choice is yours.


Making the Change

If you have considered all that has been discussed here and have decided to proceed with the changes, now what? Depending on your ATV and the extent of larger wheel diameter, you may need to make a few modifications. The extra components may include lift kits, wheel spacers, heavy-duty components like heavy-duty suspension and so on. However, if the increase is small, you may not need to make any modifications on your ATV at all.


When Modification is Not Required

If you need a slight increase in ground clearance, you probably don’t need to make any modifications to your ATV. The requirement will, however, depend on your particular ATV. Generally, most manufacturers like Yamaha and Polaris ATVs leave enough clearance to increase tire sizes by one size at least and maybe even two.

You want to ensure that the new tires don’t rub on the exhaust, shocks or plastic parts. Although you may be able to increase the tire size by two sizes, you should probably double it by one size for an ATV of less than 500 cc. As we mentioned earlier, even if modifications aren’t required, check the warranty terms before adding a new tire.


Lift Kits

If you are going to increase the size of your ATV tires considerably, then you will need to make modifications to the vehicle. The first consideration is the installation of a suspension lift kit. The purpose of a lift kit is to raise the height of the suspension to provide clearance for the new tire. It also helps to increase the ground clearance which is required due to the added height of the taller tire. The ideal size of the lift kit needed will depend on the size of the new tires. If you have a larger ATV, the possibilities are unlimited.


Wheel Spacers

Wheel spacers are associated with wider tires. However, there is some benefit to be gained by wheel spacers for taller tires as well. As the tire now has a wider diameter, it is prone to rubbing while turning which can damage the ATV as well as the tires. The purpose of a wheel spacer is to position the wheel so that it is not too flush with the body of the vehicle.

You will also find that wheel spacers add stability to your ATV. With the increase in height due to taller tires, the center of gravity also gets raised. However, the wheel spacers push the wheels outwards, hence dispersing the weight of the vehicle more evenly. You will feel the difference while turning in sharp corners. You can also achieve stability by adjusting the offset of the wheel, but it is a tricky process.


Heavy Duty Suspension and Drivetrain Components

Having all that extra weight added from a larger tire and increased angles because the height has now been increased, puts additional stress on the drivetrain and suspension. You may have to upgrade these components. Axles, CV joints, and shocks may also form part of your upgrade list. Without upgrading these heavy duty components, they will wear out faster and may even fail during mid-operation.


Choosing a Suitable ATV Tire

Any discussion on the effect of tires on ATV performance would be incomplete without touching upon how to select the right tire. It can be a more complicated task than you could imagine. Although you can get specialized tires, a dedicated tire can prove to be an expensive proposition. A few commercially-available tires include sand tires, all-terrain tires, sport and race tires, mud tires and snow tires.

Depending on the design, different tires will follow different tread patterns according to the tread design, each one with a specific ply rating. Each tire will give you a particular performance according to design and specific ply ratings:


All-Terrain Tires

As the name indicates, these are general purpose tires that will work in all terrains. However, don’t expect exceptional performance in any specific off-road situation from an all-terrain tire.


Mud Tires

You will need these tires if you expect to travel a lot in deep mud. Mud tires will work well in a sloshy terrain including snow to some extent but are less durable on hard pack or rocky terrain.


Sand Tires

A sand tire is useful if you expect to drive over sandy terrain. The wider tire and paddle in the tread pattern prevents the tire from sinking into the loose sand.


Racing Tires

If you are into a competitive sport with your ATV, racing tires will work well for you at high speeds. These tires have different tread designs built for high speed, best understood by an experienced racer.


Choosing the Right Tires can Give you a Great Off-Road Experience

We hope that you got some useful information from this article to use your ATV or UTV efficiently. Now you know more about the effects of tire size on ATV performance. The fewer modifications you make will maintain the standards set by your OEM. However, if circumstances so dictate, you now can select the right category of a bigger tire to get the best out of your ATV. Contact Westshore Marine Today




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