Handy guide for bicycle maintenance

By Christian Jensen - 15.02.2026

A bicycle is a combination of many mechanical components. Proper maintenance is essential. Neglecting it can be dangerous both for you and for others you meet on the road. This guide will walk you through a basic bike service.

Handlebar and steering components

Checking the bearings

• Turn the handlebar so the front wheel points straight ahead.
• Lift the bike so the front wheel is off the ground. Do not lift by the handlebar — hold the frame instead.
• The handlebar should swing freely to either side. Listen for unusual sounds.
• If the handlebar does not swing, the bearings are too tight.
• If the handlebar swings slowly and shakily to one side, the bearings are too loose.

Set the bike down and apply the front brake. Rock the bike back and forth. Any play in the bearings will reveal itself as clicking sounds.

Adjusting the bearings

• At the top of the headset you’ll find a locknut. Loosen it a couple of turns.
• Below the locknut you may find accessories such as reflector brackets. Under these is the adjustment nut.
  • Turn counterclockwise to loosen
  • Turn clockwise to tighten
• If you need to loosen the bearings, poor lubrication may also be the cause. It can be worth opening the assembly a few turns and applying fresh grease to the bearing balls. Be careful not to lose any of them.

Checking bolts on the handlebar

• Bell and accessories: Tighten clockwise
• Stem bolt: Sometimes covered by a rubber cap. Remove the cap and tighten clockwise
• Handlebar clamp (stem faceplate): Usually 2 or 4 bolts. Tighten clockwise
• Brake and gear levers: Tighten clockwise

Crankset (Pedal assembly)

Checking the bearings

• Hold one crank arm and push it sideways toward the frame. If it moves, the bearings need tightening.
• External and semi-external bottom brackets have lockrings/bolts that can be tightened.
  • Note: Some cranksets use left-hand threads on the left side — meaning they tighten counterclockwise. Look for an arrow or the word “links”.

Check the crank arms for cracks or damage — they endure alternating loads and can develop fatigue fractures.

Pedals

• Pedals are mounted with a bolt through the center. Wiggle the pedal up and down; if there is play, tighten the bolt.
  • Note: Most pedals have a left-hand thread on the right side — meaning they tighten counterclockwise. Look for an arrow or the word “links”.

For clip-in pedals, inspect the mechanism for stones or debris. Also check that your shoes release properly. Adjust according to the pedal/shoe manual if needed.

Saddle

Checking the mounting

• Inspect the seat clamp bolt or quick-release for damage or deformation. Years of use can bend the bolt — replace if necessary.
• Under the saddle you’ll find several adjustment points. Ensure all are properly tightened.
• Some saddles have a tilt adjustment that requires tightening one bolt relative to another.

Hubs

The hubs allow the wheels to spin around their axles. To check them:

1. Lift the bike and spin the wheel.
   • If the brakes rub, disconnect them first.
   • If the wheel makes noise or stops quickly, inspect the hub.
   • The rear wheel’s freewheel can make this trickier — sometimes it’s easier to remove the wheel entirely.
2. Grab the rim and try to move the wheel sideways.
   • A clicking sound indicates play in the hub bearings.

Inspecting and servicing the hub

If the hub spins poorly, it is usually due to poor lubrication. Servicing a hub can be messy — lay down newspaper and work carefully. Most hubs use loose ball bearings that may fall out one by one.

1. Remove the wheel and loosen the locknut next to the hub.
   • Do not lift the wheel off the axle — the bearings on the opposite side may fall out.
2. When the nut is fully removed, you’ll see the bearing balls. Remove them if possible.
3. Lift the wheel by the axle and tilt it while keeping the axle aligned with the hub.
4. On the opposite side, lift slightly to access the bearings there as well.
5. Finally, loosen the end nut on that side if needed.

Cleaning

• Clean the bearing races thoroughly. Engine degreaser works well to dissolve old grease.
• Wipe with technical alcohol afterward to remove residue.
• Clean the bearing balls in degreaser, then alcohol. Dry them carefully.
• Do not mix left and right bearing balls.

Use a cotton swab to check the bearing races for scratches — if cotton catches, inspect more closely.

Reassembly

If no major damage is found:

• Apply generous grease to both bearing races.
• Place the balls into the race on the hub.
• Grease all four surfaces before inserting the axle and repeating the process on the other side.
• Reassemble and tighten the hub.

If the wheel had play, it was likely due to loose hub adjustment. Tighten the nuts on both sides using two wrenches — the axle is continuous and free-spinning.

Drivetrain

The drivetrain consists of the front chainring, rear cassette, derailleurs, chain, and shifters. It gets dirty quickly due to oil attracting sand and grit.

• Use degreaser to remove old oil.
  • Avoid getting degreaser near bearings — it can seep into poorly sealed areas and dissolve grease.
• Use a toothbrush or scrub brush to clean all teeth on the chainrings and cogs.
• The two small jockey wheels on the rear derailleur often accumulate the most grime.
  • A flat screwdriver can help scrape it off.
• Spin the pedals backward while holding the screwdriver against the jockey wheel to remove buildup.

Wash off old oil and degreaser using alcohol or mild soap. Lubricate thoroughly afterward.

Cables

• Inspect and lubricate all cables.
• If the bike shifts poorly, the cable tension is incorrect.
  • Most shifters have a barrel adjuster — turn it until shifting becomes accurate.
  • Note: The two screws on the derailleur itself are not for cable tension — they set the upper and lower travel limits.

Brakes

Brakes are the most important safety component on your bike. You must have a functioning front and rear brake, each working independently.

• Lubricate all cables to reduce friction.
• Adjust the brakes according to their type, ensuring they engage properly without rubbing the wheel.
• Check brake pads for wear and replace if necessary.

Suspension

Finally, inspect the suspension (if your bike has it):

• Ensure the stanchions are lubricated and free of scratches.
• For air shocks, check the pressure periodically.
• Suspension that does not function properly usually needs professional servicing.