How to buy a used bicycle - and why carbon frames are a special problem

I’ve sold several of the kid’s bikes (at bargain prices!), but this week was my first purchase of a used bicycle. It didn’t go well. Consequently I’ve learned a lot about the high end sold-by-owner used bicycle market. In the spirit of turning pain into a learning experience, I’ll share my personal recommendations.

First, however, I’ll warn you that George Akerloff would say you really shouldn’t do this. Consider buying from a reputable used bike shop that offers a warranty — but I think most high end used bikes are sold by owner.

1. Be ready to walk away. Remember the seller knows a lot more about the bicycle than you do, so they have the advantage. Don’t travel somewhere to look the bike over — that makes it very hard to walk away. Sellers don’t want to travel either, so you should probably restrict your search to local sellers.
2. If you aren’t an expert, bring an expert. If you can’t bring an expert, ask a bike shop you trust if you can pay for a pre-sale inspection and ask that of the seller. Explain that you lack expertise to evaluate the bike.
3. Carbon frames are a special risk. I’ve read claims they don’t fail any more often than a steel or aluminum frame; that’s crazy talk. They are wonderful, and easier to repair than aluminum or steel, but they fail in an obnoxious number of ways. What makes that more tolerable is the lifetime warranties quality vendors provide on high end frames. Those warranties are generally not transferrable however, so a carbon frame is worth a lot more to the original owner than it is to you. You should expect a big price drop on a carbon frame bike, and if you don’t have a manufacturer warranty you need a good local source for carbon frame repair.
4. Research the original list price, remembering that people who buy good bikes often negotiate 25-35% discounts.
5. You really don’t want to buy a stolen bike. I avoided Craigslist for that reason and went through a local Facebook bike sell/trade group. I knew my seller’s name, home town, job, reputation in the local bike community and more. Even so, I think I bought a gray market bike — sold via eBay by a Cannondale dealer for less than authorized price — maybe without paperwork. Request a copy of the purchase records when buying a bike less than 6-10 years old. Many people won’t have these, but give special attention to any seller who can provide them.

That said, from what I hear from the local mountain bike community most sellers are remarkably conscientious — in one case assisting with a warranty replacement 1 year after the sale. That’s extreme! So even if you don’t follow all of these rules, you may do very well.