the adult bible - second hand bikes

What to look out for when purchasing a second hand bike

There are a few things to look out for when you purchase or are looking at a second hand bike;

1. Check the frame

Have a look around the welds and joints – are there any cracks?

Check underneath the frame where the tubes join, pay close attention to the welding of where the tubes join the frame because this is where the stress points are.

2. Check chain wear

Preferably, you need a chain checker tool to check chain wear – you can get this from any basic bike shop. It looks like a steel ruler with a pick/pointer at each end. The chain checker measures the chain stretch, which essentially checks the distance between each of the rollers in the chain (rollers are what look like the knuckles/knots in the chain).

If you don’t have a chain checker, you need to have a close look and make sure you can’t see daylight through the chain and the chain ring.

The more the bike is used, the wider the gap between the rollers will be, generally speaking.

3. Check the bearings

Headset

If you twist the handle bars, can you feel the head set? If it feels smooth when you twist it, it’s probably okay but if it feels like rocks you will most likely need a new headset. These roughly cost around £40 for a standard set.

Bottom bracket

To check the bottom bracket, take the chain off the chain rings and spin the pedal lever backwards, if it feels smooth it’s okay but if it feels like it’s grinding it needs replacing. These roughly cost around £20 for a standard bottom bracket.

Wheels

You need to do the same checks with the wheels. If you lift the wheel off the floor by the frame and spin it, it should feel smooth, if it feels smooth then it’s okay. If it feels glitchy you may need a new wheel bearing or a new wheel. Check both the front and the rear wheel. To replace, these roughly cost £20 for a standard set on the front and £25 for the bearings on the rear, as standard.

If there is a wobble in the wheel you may need to get it trued (straightened) – at a bike shop this typically costs approx £15 (understandably this will vary slightly depending on how bad the condition of the bike is).

4. Look at the rubber component

If the bike has been in storage or sat in the garage for a while, the rubber components are likely to be the first parts to perish. This means the tyres, the break pads and the other cables.

Tyres

Tyres can get cracks on the side walls – even if they haven’t been worn a lot and have been lying around for a while, so check this. It’s advisable to replace the tyres if they’re cracked as they will be puncture prone.

On some tyres (generally slightly more expensive tyres) there may be a tyre wear indicator – this is an engraved dot that you can use to measure wear because if the rubber has been worn down to the dot, it is due a replacement.

Most tyres are directional (they work best facing a certain way) – they’ll always be an arrow on the side wall of the tyre to show which way to put the tyre on. If they have been put on backwards, they’ll wear quicker because of the tread.

Brake pads

Check there is enough meat on the pads. If it is a V break pad, there are lines to show you how much they’ve been used and how much wear you have left before they need to be replaced. If you have disc break pads, you need to remove the wheel and have a closer look and make an educated decision as to how much physical wear is left.

If you can see metal or the pads are anywhere near metal, they need replacing immediately and the bike shouldn’t be ridden until they are changed. Break pads roughly cost around £10-16 a pair.

Gear cables

It is recommended that gear and break cables are replaced once a year, regardless of how many times a year you use the bike (they wear even when sitting still). Note – if you have hydraulic gear and break cables, this is not the case, you’ll need to check the recommended life span with the manufacturer or your local bike shop.

Please note all prices above do not include labour – you’ll need to take this into consideration if you are getting any parts of a bike repaired/fixed at a bike shop.

For more information on second hand bike repairs, visit Giant Guildford.

second hand bike - the adult bible the adult bible - second hand bikes