Tips for buying a pre-owned bike

A used bike can have plenty of riding left in it. Take your time with the parts below, and ask questions if something does not feel right.

Wheels and tires

Wheels can be steel, aluminum or carbon. Spin them and look for wobble: a minor one in an aluminum wheel can be corrected by adjusting the spokes, but a badly bent steel wheel is probably ready for the garbage bin. Check the tires for wear, and for bulges, cracks or tears in the sidewalls.

Axles, bearings and headset

The bottom bracket, axles and headset are often overlooked, and they can be expensive to repair. Side to side movement or looseness often means new bearings. I see many that are dried out and worn from a lack of maintenance.

Derailleurs and shifters

Make sure the handlebar controls move both the front and rear derailleurs. The rear derailleur hangs on a hanger that is often bent if the bike has been dropped or hit on that side. Sometimes the problem is just the cable, which takes me to the next point.

Cables and housing

Cables stretch and rust over time, especially if the housing is cracked or worn out. They are not expensive, so replace them if needed. Friction or stiffness can be a sign of a problem.

Chain and cassette

Chain wear is hard to judge without a chain checker. A dirty, rusty, dry chain may be worn out, and worn cassette teeth make shifting rough and can make the chain jump. It is probably the most neglected part I see on bikes.

Brakes

Rim or disc, pull the levers and feel for smooth operation at the wheel. Worn pads, cables and housing can all affect braking, and sometimes it is only a matter of adjustment. If a hydraulic lever pulls close to the handlebar, the system probably needs to be bled.

Frame

Check for cracks and visible flaws, and for rust on a steel frame. If the frame is damaged, the rest of the bike is generally useless. Carbon fibre has a torque setting for pretty much every bolt, and if you overtighten it the carbon will crack and be difficult and costly to repair.