GUIDE · WEAR
Bike component wear: when to check each part
How worn a bike is does not depend on mileage alone. The chain, cassette, brake pads and tyres wear according to where, how and in what conditions you ride. This guide explains which factors matter, which parts deserve attention and how to track wear part by part without making up numbers.
Pedalytics is in preparation and cannot be downloaded or used yet. This guide explains the approach it is being built around. Meet Pedalytics
What makes a part wear out
Two bikes with the same mileage can be in very different shape. These are the factors that matter most:
- Terrain and climbing: steeper roads and more effort load the drivetrain, and long descents load the brakes.
- Rain, mud, dust and sand: they act as an abrasive and wash the lubricant away.
- Cleaning and lubrication: a clean, well-lubricated drivetrain wears more slowly than a dirty or dry one.
- Effort: power, weight and pedalling style change how hard each part works.
- Fitment: pairing a badly worn chain with a new cassette tends to speed up the cassette's wear.
That is why a single mileage interval does not suit every ride or every bike.
The parts most worth watching
- Drivetrain (chain, cassette and chainrings): they wear together, and the chain is usually the part that is measured and replaced first.
- Brakes (pads and rotors): wear grows with long descents, rider weight and water or mud.
- Tyres: they depend on terrain, pressure and compound.
- Cables and housing: they degrade with dirt and time, and you notice it in the feel of the shifting and braking.
- Bearings (headset, wheels and bottom bracket): they show up as play, noise or a rough feel.
Other parts, such as the frame, rigid forks or handlebars, have no reliably published replacement interval. For those, regular inspection is the sensible approach.
How to track wear part by part
- Record every component with the bike it is fitted to and its installation date.
- Link every ride to the bike, and therefore the parts, you rode it on.
- Note the conditions: rain, mud, terrain and climbing.
- Compare against the manufacturer's guidance or a direct measurement, and log every cleaning, lubrication, inspection and replacement.
- When you replace a part, keep its earlier history tied to the old part.
A spreadsheet works, but it takes discipline. This is where a tool that remembers each ride's setup saves effort.
How Pedalytics approaches it
Pedalytics, an app still in preparation, starts from three ideas:
- Every ride keeps a snapshot of the setup the bike had, so history is not rewritten when you swap a part.
- Wear is explained through mechanical load (terrain, rain, mud and climbing) rather than distance alone.
- Every maintenance interval cites its source, either the manufacturer's guidance or an independent measurement, and where no reliable figure exists it suggests an inspection.
It is an explainable estimate, not a measurement: you can always see where each number comes from.
Frequently asked questions
How many kilometres should a bike chain last?
There is no universal figure. It depends on the manufacturer, the type of drivetrain and the conditions you ride in. The sensible approach is to follow your manufacturer's guidance and check wear with a direct measurement. Pedalytics does not invent a mileage: it uses the published source and, where none exists, suggests an inspection.
Is mileage enough to know when to replace a part?
It is a reference, but it ignores terrain, rain, mud and climbing. Two bikes with the same mileage can wear very differently.
Which parts have no reliable replacement interval?
Generally frames, rigid forks and handlebars: there is no reliably published mileage, so the recommendation is to inspect them regularly.
What is mechanical load?
It is a way of expressing how much work your components have endured, taking into account more than distance. The guide on mechanical load and distance explains it in detail.