How to tell when it’s time for a major bike service

A bike rarely starts causing problems overnight – in most cases, it gives you warning signs gradually. At first, you may notice a slightly noisier chain or poorer shifting when climbing. Later, the chain may start skipping under load, the brakes may squeal, or the wheel may begin to wobble unpleasantly at higher speeds. If you notice these warning signs early enough, you can identify the problem before it turns into an inconvenient breakdown during a ride. Find out which symptoms to watch for while riding and when it is time to leave your bike in the hands of experienced mechanics.

What does a major bike service include?

A major bike service is not just a quick chain lubrication and topping up tyre pressure before a ride. It involves a more thorough inspection of the entire bike and replacement of components that are already worn.
It typically includes:

• inspection and possible replacement of the chain,
• inspection of the cassette and chainrings,
• gear adjustment,
• inspection of brakes, brake pads, rotors or brake shoes,
• inspection of bearings in the bottom bracket, headset and hubs,
• inspection of tyres, rims and wheel spokes,
• tightening of bolts and connections,
• inspection of the suspension,
• cleaning and lubrication of the drivetrain.

While you can handle routine maintenance at home using basic tools and bike maintenance products, a major service often requires more precise diagnostics, specialist tools and experience in determining which components should be replaced together. Our professional mechanics at the Axit store can help you with exactly that.

A skipping chain is one of the first signs that the drivetrain is under strain

Whether you ride a classic MTB, a road bike, or an e-bike, the drivetrain is one of the fastest-wearing parts of the bike. A skipping chain is one of the most common signs that something is wrong with the drivetrain. It usually happens when you push harder on the pedals – for example when setting off or climbing. The chain briefly skips over the teeth of the cassette or chainring, causing an unpleasant jolt.

A skipping chain usually means that one of the drivetrain components is no longer working correctly. The cause may be a worn chain, but also a worn cassette, a damaged or worn chainring, or even a poorly adjusted rear derailleur, stretched cable or contaminated outer housing. If the chain skips only on one particular sprocket, the cassette is often the source of the problem. If it happens across several gears, start by checking the chain and adjusting the shifting.

When should you replace your bike chain?

The best way to check whether a chain is worn is to use a chain checker. It quickly shows whether the chain is still within tolerance or whether it is time for replacement. Replace your bike chain before it starts damaging the rest of the drivetrain. We have also prepared a simple guide on how to fit a new bike chain.

Replacing the chain did not help? It may be time for a new cassette and chainring too

Sometimes you replace the chain but the problem remains. A new chain skips on the old cassette, shifting is inaccurate and you can still feel jerking under load. This is a sign that the cassette is worn as well. Typical symptoms include the chain skipping on the most frequently used sprockets, teeth that have become sharp or irregularly shaped, and noisy shifting even after adjustment.

Replacing the cassette makes particular sense if you have ridden for a long time with an elongated chain. The worn chain gradually wears the sprocket teeth to match its shape, and a new chain will no longer mesh with them correctly. If you want to replace the cassette on your bike, you will need the correct cassette remover and the right feel when tightening it. A competent home mechanic with the proper tools can usually do this themselves, but if you are unsure about the cassette type, freehub body or chain compatibility, it is better to choose a professional bike service.

Chainrings are often overlooked

The chainring is a fairly unobtrusive component. While you can measure chain wear with a chain checker and often suspect the cassette when the chain starts skipping, the chainring is sometimes forgotten. Yet it is subjected to considerable force every time you pedal.

A chainring may need to be replaced if:

• the teeth have become noticeably sharp;
• the chain does not sit properly on the chainring;
• the chain drops off the chainring;
• you feel irregular jerking under load;
• a new chain and cassette have not solved the problem;
• the chainring is bent or mechanically damaged.

The brakes squeal, rub or no longer work as well as they used to

When it comes to brakes, it is not worth waiting. Which warning signs indicate that something is wrong? If your brakes continue to squeal, lose braking power, the lever pulls all the way to the handlebar, or you feel pulsing while braking, it is time for an inspection. Some cyclists can handle brake rotor cleaning and brake pad replacement at home. Bleeding hydraulic disc brakes, straightening a rotor or diagnosing inconsistent braking performance is, however, better left to experienced mechanics.

The wheel wobbles from side to side

You can usually tell that a wheel is out of true or that there is a problem with the spokes if:

• the rim moves from side to side as the wheel rotates;
• the bike vibrates while riding;
• loose spokes make a ringing sound or have noticeably different tension.

A slight wheel misalignment can sometimes be corrected with a spoke key. If the rim wobbles significantly, is dented, has a cracked nipple or several loose spokes, do not postpone a visit to the workshop. Riding with a badly out-of-true wheel can impair handling and cause further damage to the wheel.

You should also pay attention to the bottom bracket and headset. Regular clicking or cracking noises that correspond with crank rotation can indicate a problem with sealed bearings. Similarly, wear on the inner surfaces of suspension forks may indicate that replacement of the fork and shock oil has been neglected.

Shifting is slow, inaccurate or keeps going out of adjustment

Gear changes should be smooth and predictable. If the rear derailleur is reluctant to shift or the chain falls between sprockets, the problem may not only be adjustment but also worn inner cables, outer housing, the cassette, chain or a bent derailleur hanger. Basic adjustment can be done at home. However, a bent hanger, cable replacement, precise limit screw adjustment or diagnosing a worn drivetrain should not be underestimated.

When should you take your bike to a workshop, and what can you do yourself?

At home, you can wash your bike, clean and lubricate the chain, check tyre pressure and tighten basic bolts and connections, measure chain wear with a chain checker or replace some simpler components. We have covered how to service your bike at home in more detail in one of our previous articles.

Take your bike to a workshop if the chain continues to skip even after replacement or adjustment, the brakes lose power or need bleeding, the wheel is significantly out of true, or you hear regular cracking, clicking or grinding noises. A major bike service is also worthwhile before a longer cycling holiday or after hundreds of kilometres of riding. You should also visit a professional workshop if the bike has been involved in a crash or suffered a significant impact. In short, a major bike service becomes necessary when the bike starts behaving differently from usual. If you are unsure whether the problem is caused by adjustment or “only” by worn components, it is better to have the bike inspected by a professional mechanic.