Ask a Mechanic: How to Not Get Ripped Off Buying Used Bikes

Question: What should I check for when I am shopping for a second-hand bike? From: Matt

Answer: Aside from the obvious items such as true wheels, accurate shifting and braking, and general wear & tear, most people overlook wear that is hard to diagnose without a trained eye.

Use a chain checker to determine chain wear. Inspect the chainrings and cassette for the kind of wear that we pointed out in our video on determining cassette wear.

You should also pull the wheels off the bike and check the hub bearings to see if they spin smoothly. You can check the bottom bracket bearings this way as well by removing the chain from the chainrings and letting it rest on the bottom bracket while you spin the cranks.

To see if the bike has been washed too aggressively or if the bike saw a lot of use in the rain, remove the seatpost and turn the bike upside down to see if any water trickles out. You can also remove the stem and upper headset assembly very easily to see if the headset bearings are rusted; another telltale sign of a poorly cared for bike.

Lastly, and perhaps most importantly, is to check the wheels for even spoke tension and roundness. It’s easy to fool an unsuspecting buyer by taking a thrashed wheel and making it true. However, to achieve this usually requires wildly uneven spoke tension and wheels that are just out of round enough to where you won’t notice unless you are looking closely. Wheels are a big expense, so make sure you get some that are in good working order.

Keep in mind that even if a bike has a problem in any one of these areas, it doesn’t mean it’s a bad buy if the price is right; just budget in the cost of replacement parts and tools that you’ll need to bring the bike up to snuff.

For example: that bike with the stripped out crank arm may be a real diamond in the rough that someone wants to unload because it’s currently unrideable. For the price of a new crank arm or crankset plus the price of the bike, you could have a great deal on your hands, especially if you do the work yourself.

Welcome to our Ask a Mechanic column where our expert mechanics Daniel Slusser and Greg O’Keeffe answer your bike maintenance questions. If you have a question for us, please post it on the Art’s Cyclery Facebook Wall or e-mail Daniel directly at To see more great how to videos click on the highlighted link to subscribe to our YouTube channel and stay up to date on each episode of the Art’s Cyclery/VeloNews Ask a Mechanic Series.