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Out of all the modifications you can make to a motorcycle, putting on larger tires is one of the most profound. This can improve traction, enhance the appearance and even change how it handles. However, when upsizing your tires there are more factors than just buying a bigger tire and slapping it on. The process includes calculations to ensure safety as well as performance isn’t compromised.

This complete guide will take you through everything there is about up-sizing your motorcycle’s tyres and introduce Motorcycle Tire Upsize Calculator which is an essential part in this process.

Knowing Motorcycle Tyre Sizes

The first thing you need before using a tyre upsize calculator is understanding how motorcycle tyre sizes work. Normally, they’re expressed in numbers like 120/70-17. Every part of this code gives information about the tire.

Breaking down the code

  • Width: The width of the tyre represented by the first number (e.g., 120 millimeters)
  • Aspect Ratio: The second number (70) gives sidewall height as percentage of width
  • Rim Diameter: The rim diameter indicated by last figure (17 inches)

Radial vs Bias-Ply Tyres

Tyres are also constructed differently i.e., radial or bias-ply. Radial tires offer better performance and durability denoted by an ‘R’ in their sizes while bias-ply ones indicated with ‘B’, are known for their load carrying capacity and flexibility.

Definition of Upsizing

Upsizing refers to fitting wider, taller or both types compared to stock counterparts thus affecting various areas regarding how a motorcycle performs or handles.


  • Grip Enhancement: A wide contact patch between road surface and rubber improves traction.
  • Better Looks: Bigger tyres look more aggressive which many riders prefer.
  • Increased Stability: Especially at higher speeds larger tires can enhance stability of the motorbike.


  • Handling: Changing tires improperly may lead to poor handling characteristics.
  • Speedometer: The speedometer will show incorrect readings if you change its size too much.
  • Fitment: Some motorcycles cannot accommodate bigger sizes unless modified.

How a Motorcycle Tyre Upsize Calculator Works

This calculator is necessary for determining the right fitment of larger tyres without compromising on performance or safety of your bike.

Entering data

To use this tool, enter your current tire size and what you are considering. Different measurements will be shown by the calculator which help in understanding the impact that comes with changing sizes.

Important metrics to consider

  • Overall Diameter: This affects your speedometer and odometer readings because it shows how tall a tyre is in total.
  • Circumference: It tells you how far one wheel revolution makes your bike travel. A big difference may affect gearing ratios on your motorcycle.
  • Sidewall Height: Ride quality as well as handling characteristics are affected by this number; comfort might improve with larger sidewalls but precision reduces.

Step-By-Step Guide to Increasing the Size of Your Motorcycle Tires

Let’s go over how you would upsize your tires using a fictional example. Say, for instance, that your current tire size is 120/70-17 and you are considering switching to a 130/70-17.

Step 1: Measure Current Size

Start by writing down your current tire size (120/70-17).

Step 2: Utilize the Upsize Calculator

Put your current size plus the size you are thinking about switching to (130/70-17) into the motorcycle tire upsizing calculator. The calculator will provide detailed comparisons, displaying changes in diameter, circumference, sidewall height and width.

Step 3: Interpret the Results

– Diameter Change: If the diameter change falls within 3-4%, it is generally acceptable. However, anything beyond this may require further adjustments.

– Circumference Change: Significant changes can affect speedometer accuracy. Check if there are provisions for recalibrating speedometers in motorcycles.

– Width Increase: Make sure that increasing width does not cause any clearance issues with swingarms or chains.

– Sidewall Height: Think about how this will impact comfort during rides and handling ability.

Step 4: Physical Fitment Check

Regardless of whether or not potential fitment is indicated by the calculator, one should physically try out new tyres on their bikes . Look out for possible clearance problems and also ascertain if they properly fit onto rims.

Step 5: Test Ride

Once fitted with a new tyre, take your bike on a test ride observing any variations in braking power as well as overall quality of driving experience; ensure that no parts rub against each other due to inadequate space allowances or incorrect sizing .

Common Mistakes People Make When Upsizing Their Motorcycle Tyres

Disregarding Manufacturer Recommendations

It’s always best to start off by following what the manufacturers recommend. Going too far from these suggestions could result into handling problems or even compromise safety.

Failure to Account for Speed and Load Ratings

The speed rating associated with your original tire must not be exceeded by the new one while also ensuring that it meets/exceeds load rating; failure to do so can affect performance levels adversely.

Forgetting About Recalibrating Speedometers

If a significant change in circumference arises due to new size adopted then calibration might have to be adjusted accordingly for accurate readings on speedometers .

Neglecting Physical Fitment Check

Even if calculator shows perfect fit, always conduct physical check as there could still be unforeseen issues under real world conditions such as rubbing against other parts or lack of sufficient clearances.


When you upsize motorcycle tires, you increase its contact patch area with the ground which greatly affects grip among other things. This however does not mean that any bigger tyre will do because there are several factors involved like width and height ratios which could lead to poor aesthetics or even worse performance than before. If done correctly though this modification can bring about better looks and feel as well as improved traction so take time calculate necessary sizes using tools such as upsize calculators etc., follow procedure correctly hence avoid riding experience dissatisfaction due wrong calculations

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