Here at the workshop at Zenith Motorcycles, tyres are a major part of our daily workload. Weather its repairing, replacing or checking tyres, no one knows rubber like us!
We are often asked, “How do I know when motorcycle tyres need replacing?” or “How do I know if my tyres are worn?” So, this article will hopefully address some tyre-related questions and help you know when to check and what to look for.
Knowing when to change your tyres is a mix of simple visual checks and paying attention to how the bike feels. Unlike cars, where you mostly worry about tread depth, motorbike tyres can become dangerous through shape deformation and age, even if they have minimal tread wear.
Let’s look at how to check your tyres:
The Visual “Quick Checks”
Wear Indicators (TWI): Look for small raised bumps inside the grooves of your tyre. They are marked by a “TWI” or a small logo (like the Michelin Man) on the sidewall. When the tread surface is flush with these bumps, you are at the legal limit (usually 1.0mm in the UK).
The “Square” Profile: If the centre of your tyre is flat but the sides are still “meaty,” your tyre has “squared off.” This happens from lots of motorway riding. It makes the bike feel like it “tips” or “falls” suddenly into corners rather than leaning smoothly.
Cracking or “Dry Rot”: Check the sidewalls and deep in the grooves for tiny cracks (crazing). This means the rubber is drying out and losing its grip. If you see this, the tyre is past its prime, even if it looks new.
The Age Check
Even if a tyre has never been used, the rubber compound degrades over time.
Find the Code: Look for a 4-digit number in an oval window on the sidewall (e.g., 1223).
Read the Code: The first two digits are the week; the last two are the year. 1223 means the tyre was made in the 12th week of 2023.
The Rule of Thumb: Most manufacturers recommend replacing tyres after 5 years of use or 10 years from the manufacture date, regardless of tread depth.
Handling Red Flags
Sometimes your bike tells you it needs new motorcycle tyres before your eyes do. These are the things we strongly recommend you watch for:
Vibrations: Unusual shimmying or shaking in the handlebars at certain speeds.
Heavy Steering: Feeling like you have to “muscle” the bike into a turn.
Tracking: The bike follows cracks or lines in the road (often called “tramlining”).
Slides: A sudden loss of confidence or minor “slips” in wet conditions.
MOT Rules
The MOT rules for motorcycle tyres here in the UK are not too complicated once you become aware of them, but they are too much to put into this Blog. A very quick pre-MOT inspection you should carry out before your MOT should involve you checking tyre tread depth (Motorcycles over 50cc: The tread must be at least 1.0mm deep. This depth must be present across a continuous band comprising the central three-quarters (75%) of the tread width, around the entire circumference. The remaining 25% must still have a visible tread pattern).
Make sure the tyre valves are not cracked, leaking or damaged and ensure that there is no structural damage, cuts or exposed cords, and they are fitted correctly.
Tyre Wear Summary Checklist
| Sign | What it Means | Action |
|---|---|---|
| Flush Wear Bars | Legal Limit Reached | Replace Immediately |
| Visible Cords/Wire | Structural Failure | DO NOT RIDE |
| Bulges or Bubbles | Internal Damage | Replace Immediately |
| Flat Centre Spot | Squared-off profile | Replace for Better Handling |
| Deep Punctures | Compromised Casing | Replace (Don't Just Plug) |
We hope this summary of knowing what to look for regarding tyre wear helps. Always remember, if you are unsure, ask your local trusted motorcycle shop for their advice.
