10 top tips for buying a second-hand bike

Nothing beats buying a new bike. It’s something cyclists can unanimously agree on. There’s the excitement as you choose a new steed, the thrill of taking it out of the box, and then the fun really begins on the first ride.

The only downside is the cost which, let’s be honest, can often be pretty high. Even a lower-end model can set you back up to £1,000. Work your way through the models and you’ll soon reach dizzying price points, some in excess of five digits. That’s a lot of money for a bike.

So what do you do if you’re cash-strapped, or simply can’t justify spending that much money? Why not try buying a pre-loved bike? Second-hand bikes are a cost-effective alternative for many, but we understand that there’s always a level of trepidation when dipping into the used market for the first time.

It doesn’t have to be, though, and we're here to help. From what to ask the seller to which components to check, here’s everything

you need to know when you’re on the hunt for a used bike.

Question the owner

Buying a second-hand bike can seem risky, but there are steps you can take to ensure it’s in top condition. Start by questioning the owner. Don’t interrogate them, simply ask a few questions about the bike and their experiences using it. If nothing else, it’s a great way to build rapport with the seller. It may even lead to a little bartering.

Look out for any red flags. If it becomes clear that they’re not a cyclist but they’re selling an expensive bike, it should raise some questions - you don’t want to inadvertently buy a stolen bike.

Naturally, the main topic of conversation will often be the price. If the price is really low and it stands out as being an incredible deal, those red flags should be flapping. A deal that appears to be too good to be true usually is.

Check the bike

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Scuffed saddles and bars can be clues that a bike has hit the deck

In this world where everything is available at our fingertips, it’s often tempting to simply get a bike delivered. Avoid this when buying a used bike. The most important step when buying a second-hand bike is checking it in person. How can you know if it’s damaged, excessively worn or even exists as described unless you see it with your own eyes? No one wants to be on the end of a scam.

Let’s go through all the specifics of what you should check and look out for when buying a used bike.

Bar tape

There are plenty of legitimate bargains out there, often from a seller who bought a bike with the intention of getting into the sport only for it to gather dust.

But how do you distinguish a bike with little use from one that’s clocked up many more miles? There are a few simple tells that should provide a good indication, starting with the bar tape. If it’s pristine and looks like the original tape, the bike probably hasn’t been ridden much.

Have a quick scan of the brakes too. If there’s not much wear on the wheel rims or disc brake rotors and the pads are clean and unworn, it’s another good sign.

Cables

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Cable wear is only cosmetic, but it tells us how much a bike has been used

Cables rub against a frame over time leaving marks where the paint has worn away. This can be another good indicator of how much a bike has been used.

Of course, for many cyclists, their bike is their pride and joy. That’s why many apply protective patches to their frames to prevent the cables from rubbing. If they’ve taken steps to protect the frame, you can be confident that they’ve taken good care of the rest of the bike too.

Adjust the seatpost

Why adjust the seatpost before owning the bike? For two reasons.

Firstly, it’s always good to set the seat to your preferred height to test the bike for size. Different bikes have different geometries so this is a great chance to get a feel for the size and angles of the bike.

It’ll also reveal if there are any issues such as a seized seatpost, one of the most common problems around. While this can be solved, it’s still an inconvenience. On carbon bikes, the seat clamp bolt is also one of the stress areas where damage can occur if the correct torque limits aren’t followed. Now is the chance to give it a quick once-over for any damage.

Wheels and tyres

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The rims and pads are good indicators of how much use a bike has had

Dodgy brakes should bring any potential sale to a screeching halt.

For rim brake bikes, check the wheel rim surface to ensure that it isn’t concave. This is when the rim is so worn that the surface curves inwards. If the surface is concave, the wheels will need replacing, meaning more cost. Rim brake pads can also wear, though this usually takes a very long time. But still, it’s worth checking.

Disc brake rotors also wear, though it’s much cheaper to solve this issue as only the rotors need replacing as opposed to the whole wheel. Of course, a worn disc rotor will also be a sign that the bike has clocked up a lot of miles in its lifetime and therefore might not be the best offer.

If the brakes are worn, there’s a good chance the tyres are too, unless the owner has upgraded them. Check the tread and for any cuts or bulges. See any problems? If you do, it may be worth trying to negotiate the price of the bike down a little.

Drivetrain

The drivetrain is particularly susceptible to wear and its parts have to be replaced periodically.

The first thing to check here is the chain. Chains stretch over time and a stretched chain will accelerate wear to the rest of the drivetrain. You can easily check this using a chain tool.

Have a look at the teeth on the chainrings and cassette too. They should be fairly uniform in shape and not sharp or jagged like a shark’s tooth.

Bearings

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Wheels will rattle side to side if the bearings are in poor condition

Virtually every moving part on a bike relies on bearings. These reduce friction between two surfaces, ensuring smooth movement. The main bearings in a bike are found in the headset, bottom bracket and the wheels.

To check that the headset bearings are functioning correctly, simply hold the front brake lever and push the handlebars back and forth. There shouldn’t be any rocking. If the handlebars are hard to turn or feel like they’re grinding, the bearings may need replacing.

Next up, the bottom bracket bearings. Grab hold of either crank arm and try to move it laterally. There shouldn’t be any movement.

Finally, grab hold of the wheels and try the same test, attempting to move them laterally. Again, if they can move, it means the wheel bearings in the hubs need replacing. While you’re checking that part of the bike, spin the wheels too. If the wheel wobbles as it spins, it needs truing.

Hidden damage from a crash

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Often the state of the components gives a better indication of the frame health

The biggest risk when buying a second-hand bike is damage from a crash, which isn’t always easily visible to the naked eye. How can you tell if a bike has taken a tumble?

Sometimes, the most obvious sign isn’t the frame itself, but the components. The rear derailleur is often a victim, scraping along the floor in a crash. If it has scrape marks, the bike has likely hit the tarmac at some point. This is mainly cosmetic damage but there could be functional effects too, so shift through the gears to ensure they’re not skipping. Other areas to check for scuff marks include the saddle, shifters and bar tape.

The frame is the thing to be most concerned about as damage may not always be obvious. It’s common for the top tube to incur damage as the handlebars swing into it. Turn the handlebars fully to one side to see where they would potentially strike the top tube and this will be the best area to check.

Believe it or not, alloy and steel frames can actually become warped from a crash too. This is rare and will require a tape measure to detect. Simply measure from the rear dropout to the same point of the top tube on either side of the bike. If the measurements are different, it’s best to steer clear of the bike.

Test ride

Poking and prodding alone won’t give the best picture of a bike, so always take it for a quick spin if you’re able to. Now is the chance to check once again that everything functions as it should, including the gears and brakes. Listen out for any creaking, especially from the bottom bracket area, and investigate if you have any doubts.

If a buyer won’t let you test the bike, it’s best to walk away. Why take the risk if you can’t be sure that the bike is functioning and safe to ride?

There are plenty of second-hand bargains out there, you just need to know what to look for. Follow the tips in this article and you should be able to differentiate a second-hand bike in top condition from one best avoided, and hopefully get yourself a new ride at a more affordable price.