Buying used: the pre-purchase checklist

A used bike can be the best value in cycling or an expensive mistake, and the difference is usually visible in fifteen minutes of looking. Here is what to check, in order, before money changes hands.

Before you travel: check the price

Do this first, because it decides whether the trip is worth taking. Find the model, model year, and groupset tier, and see where the asking price falls against comparable listings. A price below the 25th percentile is either a genuine deal or a sign something is wrong — the inspection tells you which. A price above the 75th needs to be justified by genuine condition or spec, not seller optimism.

The frame: the one thing you cannot fix cheaply

Components wear and get replaced. A cracked frame is the end of the bike. Spend most of your inspection time here.

Carbon frames

• ▸Inspect the high-stress areas closely: around the bottom bracket, the head tube, the seat tube/seatstay junction, the chainstays, and the dropouts. Look for cracks, not just scratches — a crack often shows as a fine dark line with paint lifting alongside it.
• ▸Press and listen. Tap suspect areas with a coin or knuckle: solid carbon rings consistently, delaminated carbon sounds dull or hollow. Compare against a known-good section of the same tube.
• ▸Ask directly whether the bike has ever been crashed. Then look for the answer yourself — fresh paint, mismatched touch-up, or a repair you were not told about.

Aluminium and steel frames

• ▸Aluminium does not crack subtly — look for dents, ripples near the head tube (a head-on impact signature), and any weld with a hairline crack.
• ▸On steel, hunt for rust, especially inside the seat tube and at the chainstay bridge. Surface rust is cosmetic; structural rust is not.

The drivetrain: how much you will spend day one

A worn drivetrain is not a deal-breaker — it is a negotiating point. A full replacement (chain, cassette, chainrings) runs roughly $150–$300 for mid-tier parts and considerably more for top-tier electronic groupsets, so know what you are looking at.

• ▸Check chain wear with a chain-checker tool if you can. No tool? Shift to the big chainring, grab the chain at the front of the ring, and pull — if it lifts noticeably away from the teeth, it is stretched.
• ▸Look at the cassette and chainring teeth. Healthy teeth are symmetrical; worn teeth look like shark fins, hooked to one side.
• ▸Shift through every gear. It should be crisp. Hesitation or chain rub can be a simple adjustment — or a bent derailleur hanger, which is cheap to fix but worth knowing.
• ▸On electronic groupsets, confirm the battery holds charge and the shifting is responsive. On hydraulic disc brakes, check the levers are firm, not spongy, and the rotors are not scored or warped.

Wheels and contact points

• ▸Spin each wheel and watch the gap at the brake or frame: a true wheel barely wobbles. Squeeze pairs of spokes — they should feel even and tight.
• ▸Grab the rim and rock it side to side. Play means worn hub bearings — serviceable, but factor it in.
• ▸Tires, bar tape, and saddle are consumables and easy to price in. Cracked, hard tires mean the bike sat unused — not damage, but a clue about how it was kept.

Fit: the deal-breaker people ignore

The best bike in the world at the wrong size is worthless to you. Confirm the frame size against the manufacturer’s geometry chart for your height and inseam before anything else — a great price on an unrideable bike is not a great price. Saddle height and stem length adjust; frame reach and stack do not.

The seller tells you a lot

A seller who knows the bike’s service history, has the original receipt or can name the shop that built it, and answers questions directly is worth more than the bike’s spec sheet suggests. Vague answers, pressure to decide fast, or a story that does not match what you are looking at are all reasons to walk. There is always another bike.