Is it worth repairing an old bike or buying a new one?

A bike that feels dead usually has a stretched chain, a worn cassette, seized cables and perished tyres, all of which are consumables with a known life. Replacing them is cheap relative to a new bike and returns the bike to how it felt when it was new. What is not cheap is a frame or wheels, and that is where the decision actually gets made.

Safety

Step by step

1. Inspect the frame and fork properly.Look for cracks at the welds, dents in the tubes, rust that has gone through rather than surface rust, and any misalignment. On a steel frame check inside the tubes if you can. Any crack, or fork damage after a crash, ends the decision.
2. Check the bearings.Turn the bars slowly with the front brake on and rock the bike — a knock means the headset. Spin the cranks with the chain off and feel for roughness — that is the bottom bracket. Spin each wheel and feel for grinding at the hub. All three are serviceable or replaceable, but they add up on a cheap bike.
3. Measure the chain and inspect the cassette.A chain wear indicator costs very little. A stretched chain that has been ridden on will have worn the cassette and possibly the chainrings, so the honest cost is the whole transmission rather than just a chain.
4. Check the wheels and rims.Spin each wheel for buckles, check the spoke tension by squeezing pairs, and on rim-brake wheels look for a concave or worn braking surface. Worn rims are unsafe and, on an inexpensive bike, replacement wheels can approach the value of the bike.
5. Price the whole job as one list, not item by item.Write down every consumable and every service item together with a labour estimate. Piecemeal spending is how people end up putting more into a bike than they intended without ever making the decision.
6. Compare against a serviced second-hand bike, not a new one.For most riders the realistic alternative is a good used bike from a shop with a warranty, which is a much closer comparison than a new one and is what makes the decision honest.
7. Weigh fit and use.A bike that fits you and suits your riding is worth spending on. A bike that never fitted, or is the wrong type for how you now ride, is worth replacing however sound it is.

Tips

• Good frames are worth reviving almost regardless of what is hanging off them. Steel and quality aluminium frames from good makers outlive several sets of components.
• A full service plus a chain, cassette, cables, pads and tyres is a standard package at most shops and is the single most transformative thing you can do to a neglected bike.
• E-bikes are a different calculation, because the battery is a large proportion of the value and has a limited life. Check battery availability and cost before spending anything on an older e-bike.

Common mistakes

• Replacing a worn chain on its own — A chain worn past its limit has reshaped the cassette teeth. A fresh chain on a worn cassette skips under load, so the job has to be done as a set.
• Riding on worn rim-brake rims — A rim that has worn thin can fail suddenly under braking pressure. This is a safety limit rather than a performance one, and it is not a repair to defer.

Questions people ask