Unlike running or swimming, cycling has a steep "barrier to entry" when it comes to cost. While it's more than acceptable to use the old commuter bike that's been collecting dust in the rafters to get started, eventually you'll want to upgrade.
However, new bikes, especially new high-performance road and mountain bikes, are expensive. It's justified, though—they're loaded with the latest and best technology—but with accurate shifting and lightweight construction comes a not-so-lightweight price tag.
If you can afford a new bike, we recommend doing so. You'll have the peace of mind knowing there will be no serious issues, and you'll have a dependable ride that will last for years to come. But if money's tight or you can't quite afford one with the specs you're looking for, a used bike is a great way to go (click here for what to look for when buying a used bike) and often provides better value for your money.
Remember, always use your best judgement when dealing with unknown sellers.
Craigslist
Sure, it's low-tech and full of spammers and scammers, but Craigslist is a solid option when looking for used bicycles. Bikes are bulky, fragile and expensive to ship, so finding a bike in your area is highly recommended. Head over the "for sale" section of your local Craigslist site and navigate to the "bikes" listing page. You'll be able to search for specific brands, sizes, types, etc., and contact the seller directly to make a deal.
If you meet in person for a "test ride," we recommend meeting in a well-lit area, preferably at a police station parking lot. If the seller isn't comfortable with that, you know they're not legit.
eBay
Another online marketplace giant, eBay has its own set of plusses and minuses. eBay requires sellers to post more specific information about their bikes, making it easier to search and find exactly what you're looking for (for example, a 2021 Men's Cannondale SuperSix EVO Carbon Disc 60 cm), and it also has a buyer protection policy to help protect you if something is shipped to your door that isn't what you ordered (or is damaged).
Unfortunately, you won't be able to try/inspect the bike before you buy, so if possible, make sure you know your size and ask for more pictures and a detailed history, including where the seller purchased the bike, how many miles it has, if it was crashed and how often it was taken in for tune-ups. Keep this conversation through eBay's platform so you have a record of the seller's responses.
Local Cycling Clubs
These are an often-overlooked source of used bikes. If you ride with a local club, send an email asking if anyone has a bike in "x" style and "x" size that they'd be willing to sell (or ask around on your next group ride). You might be surprised what turns up and you'll be able to inspect and try it out in person before buying. These people are usually trustworthy, are willing to give a good deal to fellow cyclists in their area and have likely bought the bike from your reputable local bike shop.
Bike Shops
Speaking of reputable bike shops, search around in your area and ask your local shops if they have any used bikes for sale. Local bike shops often sell used bikes (that have been traded in for credit toward a new purchase) that have been thoroughly looked over by in-house professional bike mechanics, and often older parts like tires, bar tape and brakes are replaced.
Local bike shops usually offer a free tune-up after a certain time period after purchasing, and if not, try to negotiate that into the deal (you can also negotiate the price as well).
Facebook is good for more than just life updates from family members—it's a simple and intuitive resource for finding used (and also new) bikes. Facebook Marketplace is a public listing that allows you to message the seller directly through Facebook Messenger to get all the details you're looking for, as well as more pics if needed.
While this is a great starting point, we recommend getting more specific and joining private "buy and sell" Facebook groups in your area that are specifically for bicycles (and yoou'll save money on shipping). If you aren't finding what you're looking for locally, check out groups like "Cycling Bicycle Online Swap Meet - Buy/Sell/Trade - Bikes/Frames/Parts" and "Online Swap Meet for Cycling and Triathlon" for more deals around the country.
The Pro's Closet
You likely saw their commercials throughout the 2020 Tour de France—The Pro's Closet is a great option if you're not just looking to buy a used bike but sell your current bike to help fund your new purchase, too. But if you're only interested in buying, you can shop for anything from used e-bikes and fat bikes, to used high-end road bikes and triathlon bikes (you can even see the bikes they're currently servicing and preparing to sell under the "coming soon" section). You won't find entry-level bikes here, as they only purchase used bikes with an MSRP of over $1,500, but the discounted used prices compared to new retail prices are worth considering.
READ THIS NEXT: What to Look for When Buying a Used Triathlon Bike