Understanding Motorcycle Tyre Size Numbers 

A typical motorcycle tyre size looks like this: 110/70 R17. 

Each part of this number has a specific meaning. 

110 refers to the tyre width in millimetres. This is the width of the tyre from one sidewall to the other. 

70 refers to the aspect ratio. This means the tyre’s height is 70% of its width. A lower aspect ratio generally means a sportier profile and sharper handling. 

R indicates Radial construction. If it does not include “R,” it is usually a bias (cross-ply) tyre. 

17 refers to the rim diameter in inches. This must exactly match your motorcycle’s wheel size. 

Understanding these numbers helps ensure you choose a tyre that maintains your motorcycle’s designed geometry. 

Why Correct Tyre Size Matters 

Motorcycle manufacturers design suspension, chassis geometry, braking systems, and electronics around a specific tyre size. Changing tyre dimensions can affect stability, cornering ability, and speedometer accuracy. 

Choosing the correct tyre size ensures: 

Even small deviations can alter how your motorcycle behaves at higher speeds or during emergency braking. 

Can You Upsize Your Motorcycle Tyres? 

Upsizing tyres is common among riders who want a wider rear tyre for improved road presence or perceived grip. However, wider is not always better. 

Before upsizing, consider: 

Installing a wider tyre on a rim not designed for it can distort the tyre profile, reducing actual contact patch efficiency and affecting handling. 

In many cases, sticking to the manufacturer-recommended tyre size provides the safest and most balanced performance. 

Choosing Tyre Size Based on Riding Style 

Different riding styles may influence tyre size decisions, but changes must remain within safe limits. 

City Commuting 
For daily urban riding, the stock tyre size is typically ideal. It offers balanced manoeuvrability and durability. 

Highway Touring 
Touring riders often prioritise stability. If your motorcycle supports it, radial tyres in the recommended size offer improved highway confidence. 

Performance Riding 
Sport riders benefit from lower aspect ratios that improve cornering response, but only if the motorcycle is designed for such dimensions. 

Off-Road or Mixed Terrain 
Adventure motorcycles often have specific tyre profiles designed for mixed surfaces. Changing size may reduce off-road capability. 

How to Check the Right Tyre Size for Your Bike 

To confirm the correct tyre size: 

Always match both front and rear tyre sizes according to manufacturer recommendations unless advised otherwise by a professional. 

Radial vs Bias and Tyre Size Compatibility 

Some motorcycles are designed specifically for bias tyres, while others are built for radial tyres. Switching construction types without verifying compatibility can affect ride dynamics. Even if the tyre size numbers match, the construction difference may change handling characteristics. 

Before switching from bias to radial or vice versa, ensure your motorcycle supports that construction type. 

Common Mistakes Riders Make 

Avoiding these mistakes helps maintain both safety and performance. 

Final Thoughts 

Choosing the right tyre size for your motorcycle is about more than numbers on a sidewall. It’s about preserving the balance engineers built into your machine. Whether you are commuting daily, touring across states, or riding for performance, the correct tyre size ensures stability, safety, and confidence on Indian roads. 

Before making any changes, always verify compatibility and prioritise safety over aesthetics. The right tyre size keeps your motorcycle performing exactly as it was designed to. 

FAQs 

Q1. Can I install a wider rear tyre on my motorcycle? 
Only if your motorcycle’s rim width, swingarm clearance, and manufacturer guidelines allow it. Improper upsizing can affect handling and safety. 

Q2. What happens if I change the tyre aspect ratio? 
Changing the aspect ratio alters ride height and handling characteristics, which may impact stability and speedometer accuracy.