Motorcycle MOT 2026: The 5-Category Checklist and the Legal Tyre Tread Minimum

A motorcycle needs its first MOT three years after first registration, then every year. The tester looks at five areas: braking, lighting and signals, emissions and noise, tyres and steering, structure and identification. For tyres, L'Atelier gives the UK legal minimum as 1 mm of tread across three quarters of the tread width for machines over 50cc, with 2 mm as a sensible replacement point. Defects are graded minor, major or critical, and only major and critical ones fail. Most failures are things you can check at home the week before.

Who needs an MOT, and when

L'Atelier's MOT checklist for motorcycles covers motorcycles, scooters, mopeds, quads and three-wheelers registered in the UK. The rhythm, confirmed by its selling paperwork guide: first test at three years from first registration, annually after that. The exact due date depends on your first registration date, so check it on your V5C or the DVLA reminder letter. Machines over 40 years old are generally exempt as vehicles of historic interest, provided they haven't been substantially modified; a voluntary test is still possible.

• The test is visual and functional, with no dismantling.
• A test centre inspects, it doesn't repair. The MOT doesn't replace regular maintenance.
• Defects are minor, major or critical. Only major and critical defects mean a fail.
• A failure isn't the end: the retest covers the fault you corrected, and a partial retest at the same station within the permitted window is usually free or heavily reduced.
• Your MOT history is public on gov.uk: recorded mileages, failures and advisories are visible to any future buyer.

The five categories the tester checks

L'Atelier's 2026 preparation guide groups the inspection into five categories. Here they are, filled in with what L'Atelier's MOT checklist says is examined and what most often fails:

Brakes and transmission are the next most frequent traps, and both are easy to measure yourself. L'Atelier's service-by-mileage guide treats pads under 1.5 mm as due for replacement; for disc minimum thickness, L'Atelier's 2026 guide points to the manufacturer's wear limits. For the chain, L'Atelier's chain guide gives a slack of 25 to 35 mm on most models, measured on the side stand midway between the gearbox output sprocket and the rear sprocket, but your manufacturer's figure is the one that counts. A chain that is too loose is one of the transmission faults L'Atelier lists among common failures. Finally, check the fork seals: fork oil weeping is on L'Atelier's list of leaks that come up repeatedly.

Legal tyre tread depth: the numbers that matter

Tyres are where riders most often misjudge it, so here are the figures from L'Atelier's guides side by side:

Two practical points. First, the legal limit isn't the safe limit: L'Atelier's tyre wear guide notes that a motorcycle tyre loses significant wet grip well before reaching the wear indicators, so replace it as soon as the grooves look shallow. Second, find the indicators by looking for small triangles or “TWI” on the sidewall, and read the age from the four-digit DOT code: the first two digits are the week, the last two the year (DOT 2524 = week 25 of 2024). The MOT checks tread, cuts, bulges and that the tyre is homologated for your bike.

The exhaust: the most argued-over item

A road-legal aftermarket exhaust carries a European type-approval marking (E number) stamped on the silencer, and approval applies to the precise bike and exhaust combination, according to L'Atelier's exhaust compatibility guide. Removing the removable baffle (dB killer) makes even an approved exhaust non-compliant. A track or competition pipe fails. And the marking has to stay readable: L'Atelier's Europe guide warns that an approved silencer whose stamping has been eaten away by corrosion becomes very hard to defend. The practical advice from the 2026 guide: keep your original exhaust, and refit it or the baffle before test day.

One-week preparation checklist

Combining L'Atelier's week-before list with its 30-minute evening routine (engine cold, bike on the centre stand):

1. Lights: dipped and main beam, brake light from both brakes, indicators, number plate light. Replace dead bulbs; roughly check headlight aim against a wall.
2. Tyres: tread depth and wear indicators, sidewalls for cuts and bulges, pressures set cold to your model's values.
3. Brakes: pad thickness, fluid level, lever firmness. A spongy lever often means air in the system: bleed the brakes before the test.
4. Chain and play: chain tension within the manufacturer's deflection range; no play in the steering (lift the front to check) or wheel bearings.
5. Exhaust: original or homologated, markings legible, baffle in place, mountings secure, no holes.
6. Leaks: wipe the bike down and leave cardboard under the engine overnight; investigate any drops, including fork seal weeps.
7. Mirrors and horn: both mirrors present and firm, horn working (both appear on L'Atelier's preparation checklist).
8. Side stand: L'Atelier's checklist also suggests verifying that the cut-off switch kills the engine in gear with the stand down.
9. Paperwork: bring your V5C. An illegible VIN can cause a fail.

After the test, and riding abroad

Read any advisories carefully: they don't fail the bike, but they appear in the public history, and L'Atelier's selling guide notes a buyer will price up every item listed. For trips, L'Atelier's guide to riding through Europe points out that it is the rules of the country of registration that apply: a UK bike with a valid MOT is in order across the EU, even where the local test regime differs.

For your bike's exact wear limits (disc thickness, minimum pad thickness, chain deflection, tyre pressures), ask the L'Atelier motorcycle mechanics base, for instance “What's the legal minimum tyre tread depth for a motorcycle to pass its MOT?”. Answers name the guide they come from.