What to Look For When Buying a Second Hand Bike

Using the chain checker we can see this chain is less than 0.5 worn as the hook refuses to sit inside the chain.

Using the chain checker we can see this chain is less than 0.5 worn as the hook refuses to sit inside the chain.

Using the chain checker we can see this chain is more than 0.75 worn as the checker slots into the chain and has left to right movement between the where it is hooked in at the links. This bike needs a new chain and a new cassette.

Using the chain checker we can see this chain is more than 0.75 worn as the checker slots into the chain and has left to right movement between the where it is hooked in at the links. This bike needs a new chain and a new cassette.

This tyre is cracked at the logo. Under high tyre pressure and passenger load the sidewall could split further, causing a catastrophic failure during a ride. This tyre should be replaced as a safety precaution.

This tyre is cracked at the logo. Under high tyre pressure and passenger load the sidewall could split further, causing a catastrophic failure during a ride. This tyre should be replaced as a safety precaution.

Many people decide to buy a pre-owned bicycle instead of a brand new one, and that’s awesome! We’re all for recycle and reuse. But buying a second hand bike is much like buying a used car; you need to know exactly what to look for and what questions to ask to ensure that you’re getting a good bike for a great price and not a money pit!

We’ve put together a list of things to consider when buying a second hand bicycle. A lot of what we have written here can also be check you make to a bike you already own to gauge when it might need servicing!

Drivetrain

Our absolute top tip is to invest in a chain checker. We have a very simple to use chain checker in store from Park Tools, priced at just £9.99! And yet this tool, that’s not even ten quid to buy, can save you a lot of money!

Always take a chain checker with you when you go to look at a second hand bike; and really it should be an essential tool in your home maintenance kit too!

  • Less than 0.5 - If you pop the chain checker in and it’s less than 0.5 worn, you know the chain is not stretched and you’ll get good miles from the drivetrain. You can see from the first picture the chain checker will not go in at 0.5, meaning it is not worn to this point yet.

  • 0.5 - 0.75 - If the chain is 0.5 worn but not quite 0.75 then you should look to get a new chain on the bike ASAP to prevent further wear on the cassette and chainrings, therefore increasing the longevity of the drivetrain.

  • More than 0.75 - If the chain checker goes in at 0.75 there’s a good chance you will need a new chain and cassette. This is because the chain has “stretched” and has caused the rest of the drivetrain to wear. A new chain on worn components will slip and not mesh properly!

Other areas to look at

  • Chain rings - If the inner, outer or middle rings are sharp and pointy like cats teeth then you will likely need to change those rings sooner rather than later.

  • Jockey wheels - Again, check to see if the jockey wheels are pointy like cats teeth.

  • Front and rear derailleur - Apply a little pressure to the mechs to see if there is play. Use the shifters to go up and down the cassette and to and from the chain rings to make sure the mechs move freely and the cables operate smoothly.

  • Gear Hanger - A gear hanger is a sacrificial part that connects the rear derailleur to the frame. It is designed to break and save the frame in the event of the accident. To enable it to break it is made form a soft alloy, which means it can also bend instead of breaking. If the gear hanger is bent it will cause the rear gears to misbehave.

  • Age - If you’re buying an older bike with 6 speed or 7 speed drivetrains be aware that the availability of parts might be scarce, and therefore could increase servicing costs.

Brakes

If you’re happy that the drivetrain is in good condition then the next thing to look at is the brakes.

Check the rim brake pads for wear. These are cheap consumable parts so don’t worry if they do need replacing. Pull the brake levers and see how much pull on the cable there is. If the levers pull all the way to the handlebars you may need new brake cables or a brake bleed (depending on whether you have a cabled or hydraulic system)

For disc brakes, you’ll need to check the rotors and the pads for wear.

For hydraulic disc brakes also check the levers and calipers and ensure no fluid is seeping out.

When you take the bike for a test ride be sure to thoroughly test the brakes for stopping power.

Wheels and Tyres

After gears and brakes the next thing to look at are the wheels and tyres.

The tyres are very easy to check. You should look for:

  • Cuts to the contact areas - Check where the tyre makes contact with the ground for cuts. If there are lots of cuts, especially deep ones, chances are the tyre will need to be replaced.

  • Signs of perishing - Next check the sidewalls of the tyre. If it is cracked, looking fatigued or unusually marked they tyre will need to be replaced.

Wheels are slightly trickier to check, especially if you’re not sure what you’re looking for.

  • Rim wear on braking surface - Over time, rim brakes will slowly cause the rim braking surface to feel concave. Run your thumb over the rims in several spots. They should feel fairly flat, however if you feel a significant dip in the braking surface then the rim wear could mean you need a new wheel sooner rather than later. This wear does not apply to disc brake bikes.

  • Rim condition - If the bike is ridden on a low tyre, or if the bike is crashed, the rims could show sign of damage to the braking surface or impacting how the tyre sits on the rim. Look for any imperfections on the rim wall.

  • Wheel trueness - If possible, remove the wheels from the bike and spin them on the axle in your outstretched arms. The wheel should be true both up and down and left to right.

Bearings

Bearings are trickier for the untrained eye and ear to detect, but they are well worth checking if you can.

  • Headset bearings - The headset bearings connect the fork steerer with the frame. Lift the front of the bike off the ground, so that the front wheel is in the air. Move the handlebars from left to right. The bars should move smoothly and freely. It should not feel tight, gritty or hesitant.

  • Bottom bracket bearings - Hold on to the bike and apply pressure to the chainset. If there is play left to right the bike may need new bottom bracket bearings.

  • Wheel bearings - Lift each wheel off the floor, and try to move the wheel left to right. If it has play the bearings may need to be changed.

If in doubt, ask the seller when the headset bearings, bottom bracket, wheel axle bearings and freehub bearings were changed.

Bike Fit

Finally, you need to be confident that the bike is the right fit for you. It’s all too easy to presume that because you a particular size in one make and model that you will be the same with another bike, but that is not true.

Lots of people presume that the saddle height should be set so that both feet can touch the floor when sat int he saddle, but this is incorrect too! You should only ever stand above the top tube when stationary to properly stabilise yourself and the bike. Make sure you have at least 1cm clearance between your genitals and the top tube to allow for travel in the case of an emergency stop.

To set the saddle height, straighten one leg and place the heel of the leg on the pedal (you may want to place your other leg on a step to support yourself.)

Once you are a happy with the saddle height take the bike for a ride, noting how your arms, neck and shoulders feel.

You should not feel overly stretched out, but you should also feel that you have room at the cockpit to manoeuvre the bike beneath you.

Saddle fore and aft position, saddle height, stem length and handlebar width can all greatly impact how a bike feels, and almost all road riders would feel a noticeable benefit from a bike fit, so if you do buy a road bike and the fit doesn’t feel quite right consider investing in a bike fit.

Questions to Ask

Can I take the bike for a test ride?

Are you the original owner?

When and where did you buy the bike?

Have you had any upgraded parts fitted?

When and where was the bike last serviced, and what parts were fitted to the bike as part of that service?

Has the bike ever been involved in a crash?

When were the brakes last bled? (Hydraulic disc only)

This is by no means an exhaustive list of things to check and consider. But we hope it helps you to make an informed decision and to monitor the wear and tear on your bicycle.

Ultimately, we would always advise that anyone buying a secondhand bikes immediately takes it to a bike shop for a quote and service for complete peace of mind.

And if your bike feels strange, is making unusual clicking, creaking or squeaking noises or if you’re not sure when it was last serviced simply give us a call and book your bike in for a free quote and a full breakdown on the service your bike needs.

Hannah Smith