Bike check (M check)

The basic ‘M’ check will need to be done on a regular basis. This involves conducting a safety check of all the main working parts of a bike and with practice, should take no more that between one and two minutes.   
 
Wheels

Wheel quick release /Wheel nuts
Check quick release skewer is firmly closed or that axle nuts are fully tightened.

Tyre wear
Check visually that tyres are not split or cracked and that there is tread remaining on the tyre.

Tyre pressure
Check that tyre is firmly inflated to the recommended pressure on the
tyre wall.

Hub bearings
Grip rim and rock back and for to feel for loose bearings; spin wheel to check for tight bearings.

Rims and spokes
Check visually for any defects, and spin wheel to check that it runs true. 

Brakes

Brake levers
Check angle of levers and that these can be comfortably reached. Brakes should apply pressure at 1/3 to 1/2 of travel.

Brake blocks
Check that blocks are correctly positioned and not worn beyond the wear indicators.

Brake cables
Check that cables are not frayed or heavily corroded.

The best way to check your front brake is to apply the brake and try to push your bike forward.

The same principle applies to the rear brakes.  Apply the brakes and try to move the bike backwards.

Saddle

Check that the ‘minimum insertion’ marker is not visible above the seat tube; check that post is securely gripped in frame.

Try to rock saddle in different directions to check that it is fitted securely; check visually that saddle is straight and level. 

Handlebars and headset


Stem alignment
Hold front tyre between knees and turn gently to check that the handlebar stem is correctly aligned with the front wheel and tightened.

Handlebar alignment
Check that handlebars are correctly aligned and secured by stem.

Stem height (quill only)
Check visually that stem ‘minimum insertion’ marker is not visible above steering tube.

Headset bearings
Apply brakes and rock bike back and for to feel for loose headset bearings; check that handlebars move freely.
 
Gears and transmission

Chain


Check that chain is not heavily rusted and does not easily come off front chain wheel.

Derailer position
Ensure that the rear derailleur does not foul the spokes. 

Peripherals

Lights, mudguards, racks etc.

Check that all additional items and brackets are firmly secured and do not foul moving parts.