The M Check

Checking your bike
You should get into the habit of checking your bike regularly. A good way of doing this is the ‘M’ check which ensures you don’t miss anything. Just start at the bottom of the front wheel as it is the left hand foot of the letter M and follow the shape of the letter around the bike - start with the front hub and wheel, up to the handlebars, down to the bottom bracket, back up to the saddle and end at the back wheel, looking out for potential trouble-spots in between.

M Check

What to look out for...

Start at the front wheel:
Spin the wheel – it should spin straight. If the wheel wobbles when it spins it may have a buckle and need truing – visit your bike shop.
Check for missing or broken spokes – if any spokes are broken it’s important to replace them as soon as possible as one missing spoke will make the others weaker.
Wiggle the wheel against its natural axle and check for side to side wheel movement. Listen to make sure you can’t hear any damaged bearings. If the wheel moves side to side on the axle the bearings will need to be tightened. If there is noise coming from the bearings they may need to be cleaned or replaced. If you cannot adjust the wheel yourself, take it to your bike shop.
Check the rim: some rims will have a wear line. If you can’t see this, your rim may need replacing. Check that the rim surface is flat and not concave. Check for hairline cracks in the rim. Rims that are cracked or worn away should be replaced.
Check that the tyres are pumped up to the pressure specified on the side (usually expressed in BAR or PSI) and look for wear on the tread or for any cracks in the tyre. Tyres on which most of the tread has worn away are more likely to get punctures so it is worth replacing tyres every couple of years (depending on your mileage) to avoid flats.

Then look at your brakes:
Are your brake blocks worn down? Are the blocks lined up correctly? Squeeze the brake levers: the blocks should hit the rim squarely. Make sure they do not touch the tyres. Squeeze your brake levers and push the bike forwards to make sure the brakes are effective. If you need to replace your brake blocks or adjust your brakes, see our section on brakes.

Check your stem and headset:
Stand over the front wheel holding the brakes on and push backwards and forwards (hold the top of the forks as well if you have any front fork suspension). If there is any movement the bearings may be loose – visit your bike shop. Hold the front wheel between your knees and try turning the handlebars – if the bars move without the wheel moving, your stem needs tightening: this can usually be done with an allen key.
Check that your bar ends (plugs at the ends of your handlebars) are in place – replace them if not.

Check your frame:
Look out for hairline cracks in the frame, especially at the joins. You should never ride a bike with a cracked frame, no matter how small – take it to your bike shop for advice. If you’re using this check to look at a second hand bike, feel the underside of the down tube – if the paintwork is blistered then it’s likely to have been in a collision.

Check your bottom bracket:
The part of the frame around which the cranks revolve.
Jiggle the cranks from side to side against their natural axle: if there is any movement, the bearings may be loose or your cranks may need tightening (usually either with a 14mm socket spanner or an 8mm allen key). If you are unsure, visit your bike shop.
Spin your pedals and check they are in good condition.
Check that your saddle is at the right height and is bolted tightly: remember, your leg should be almost fully extended at the bottom of a pedal stroke.

Check your back brakes and wheels as with the front.

Check your gears:
While pedaling, click through the whole range of gears (you may wish to turn your bike upside or ask someone to help you with this). If the gears don’t change smoothly, see our section on gears. Check that the cogs are not worn down.

Check that your chain is clean and lubricated – if you ride regularly, you should aim to clean and oil it once a week.
If you pay attention as you ride you will be able to notice any changes in your bike, for instance if the gears no longer change smoothly or if the handling feels a little odd. Bike maintenance is best done ‘little and often’.