6. Structure and attachments

Frame and attachments (including exhaust system and fuel system), and seat and riding controls (including clutch and throttle controls and footrests) rules and inspection for motorcycle MOT tests.

6.1. Frame and attachments

6.1.1. Frame condition

The main load bearing structure of the frame includes any sidecar frame and its attachment brackets. It does not include sections that only support components such as footrests, lamps or mudguards.

You may have to remove panels or raise the seat to be able to fully examine the structure.

If the engine is a stressed member of the frame, the engine mounting brackets should be checked (see Section 6.1.8).

You must visually assess the condition of the frame for corrosion and damage. If you notice corrosion, use finger and thumb pressure to check the extent of the corrosion and, if necessary, carefully scrape or lightly tap the affected areas with the corrosion assessment tool. Take care not to further damage the frame.

Find further guidance on assessing corrosion and methods of repair in Appendix A of this manual.

Defect reference Defect description Category
(a)(i) A main load-bearing structural member fractured or deformed such that structural rigidity is significantly reduced Major
(a)(ii) A main load-bearing structural member fractured or deformed such that steering or braking is likely to be adversely affected Dangerous
(b)(i) Joining/attachment plates or fastenings insecure Major
(b)(ii) Joining/attachment plates or fastenings so insecure that structural rigidity is seriously reduced Dangerous
(c)(i) A main load-bearing structural member corroded to the extent that the rigidity of the assembly is significantly reduced Major
(c)(ii) A main load-bearing structural member corroded to the extent that steering or braking is likely to be adversely affected Dangerous
(d)(i) A main load-bearing structural member modified or inadequately repaired such that the rigidity of the assembly is significantly reduced Major
(d)(ii) A main load-bearing structural member modified or inadequately repaired such that steering or braking is likely to be adversely affected Dangerous

6.1.2. Exhaust system

You must inspect all motorcycles with an internal combustion engine, including hybrid motorcycles.

A minor exhaust leak from, for example, a connection joint or a pinhole does not justify rejection.

Exhaust noise is assessed under Section 8.1.1.

Defect reference Defect description Category
(a) Exhaust system has a major leak or is insecure Major
(b) Not in use Ìý
(c) An exhaust silencer marked ‘NOT FOR ROAD USE’, ‘TRACK USE ONLY’ or similar words Major

6.1.3. Fuel system

You must inspect all motorcycles with an internal combustion engine or a hydrogen fuel cell.

If you cannot gain access to the fuel filler cap, see ‘refusal to test’ in the Introduction to this manual.

Defect reference Defect description Category
(a)(i) Fuel tank, pipe or hose insecure Major
(a)(ii) Fuel tank, pipe or hose insecure such that there is a risk of fire Dangerous
(b)(i) Fuel system leaking, or missing or ineffective filler cap Major
(b)(ii) Fuel system leaking excessively or a risk of fire Dangerous
(c)(i) Fuel pipe or hose chafing Minor
(c)(ii) Fuel pipe or hose damaged Major
(d) Not in use Ìý

6.1.4. Not in use

6.1.5. Not in use

6.1.6. Not in use

6.1.7. Transmission

You must inspect:

  • drive chains and sprockets
  • drive belts and pulleys

Make sure that a drive chain intended to be fitted with a horseshoe locking device has that device fitted with the closed end in the direction of rotation.

Defect reference Defect description Category
(a) Not in use Ìý
(b) Not in use Ìý
(c)(i) A transmission belt, chain, sprocket or pulley excessively loose or worn Major
(c)(ii) A transmission belt, chain, sprocket or pulley so loose or worn it is likely to fail Dangerous
(d) Not in use Ìý
(e) Not in use Ìý
(f) Not in use Ìý
(g) Not in use Ìý
(h) Not in use Ìý
(i) A drive chain or belt guard insecure Major
(j)(i) A drive chain horseshoe locking device incorrectly fitted Major
(j)(ii) A drive chain horseshoe locking device likely to become detached Dangerous
(k)(i) A transmission belt or chain excessively tight Major
(k)(ii) A transmission belt or chain excessively tight, so that it is likely to fail Dangerous

6.1.8. Engine mountings

You must inspect engine mountings on motorcycles which use the engine as a stressed member of the structure.

Defect reference Defect description Category
(a)(i) A engine mounting or bracket severely damaged or deteriorated resulting in excessive movement Major
(a)(ii) A engine mounting or bracket fractured, missing or excessively loose Dangerous

6.2. Seats and riding controls

6.2.1. Not in use

6.2.2. Not in use

6.2.3. Not in use

6.2.4. Not in use

6.2.5. Rider’s seat

Defect reference Defect description Category
(a)(i) A rider’s seat with a defective supporting structure Major
(a)(ii) A rider’s seat missing or insecure Dangerous

6.2.6. Pillion seat

This inspection does not include sidecar seats.

If there is an optional cowl replacing or covering the pillion seat at the time of test, you should consider it to be a single seat motorcycle.

Defect reference Defect description Category
(a)(i) A pillion seat with a defective supporting structure Major
(a)(ii) A pillion seat insecure Dangerous

6.2.7. Clutch and throttle controls

A throttle friction device is permitted unless it impairs the throttle operation.

A throttle does not have to automatically return to the idle position.

Defect reference Defect description Category
(a)(i) A throttle control not functioning correctly Major
(a)(ii) A throttle control functioning such that safe operation of the motorcycle is affected Dangerous
(b) A clutch lever so bent, positioned or shortened that it cannot be readily operated Major

6.2.8. Not in use

6.2.9. Not in use

6.2.10. Not in use

6.2.11. Not in use

6.2.12. Footrests

Single seat motorcycles do not need pillion footrests. If there’s an optional cowl replacing or covering the pillion seat at the time of test, you should consider it to be a single seat motorcycle.

Some motorcycles first used on or after 14 June 1993 which are designed to carry a passenger may not be fitted with pillion footrests. Instead, they are fitted with hand holds attached to the frame or seat. Refer to the owner’s handbook if available.

Defect reference Defect description Category
(a) A footrest missing or insecure Major