While Craigslist may seem like a good place to buy a used bike-- and it often is-- it is also quite possible to buy some real turkeys. Many of the sellers here are dealers who sell bikes simply for profit. There is certainly nothing wrong with that. And certainly, many are just people trying to clear an old bike out the garage or basement. There's nothing wrong with that, either. This post is meant to help those who buy bikes spot the less obvious problems with bikes. It concentrates on older road, track, and touring type bicycles, in particular those made of steel, and to an extent, aluminum. This post is for the relative newbie, so I will try to define terms and keep the tools simple.

Frame damage is the first thing a prospective buyer should look for. Very common is the bent fork or damaged frame; it may not be at first apparent. First, look at the fork. if it appears to bend backwards-- at all-- from the head tube angle this is a potential bad sign. After that, check just behind the head tube (this is the part of the bike frame the fork inserts into) on the top tube and down tube. Look for bumps, and deformations in the tubing right there. If you see these, it's probably time to walk away. Turn the frame over, and check the area around the bottom bracket for cracking. (This is especially prevalent on Cannondales and some Aluminum bicycles). The bottom bracket is the part of the frame that the crank-- you know, the thing with the pedals on it-- goes through. Other areas to check for cracking include the head tube and the rear dropouts (this is where the rear wheel inserts into the frame). Cracked frames are best to walk away from, unless you really, really, know what you're doing. Some sellers will attempt to cover cracks (and dents, which I'll talk about soon) with bondo or another filler. Bikes wrapped with stickers may hide damage. Be careful.

Take a good look at the tubes on the frame, and they should appear to be straight. Weird, unsymmetric bends are generally not a good sign, although they're not unknown in frame design. However, if you're looking at an old steel road bike, the main tubes should be straight (exception is a very few Schwinn models, which had a curved seat tube, and some customs). The stays (these come out from the bottom bracket, run to the rear dropouts, the join back to the main frame by the seat post collar-- ie, where the seat post is inserted into the frame, forming a triangle at the rear of the bike) may have some bend in them. However, if the don't look symmetrical, you can do a simple test to check alignment. You will need a string and a ruler. Tie the string to one dropout, run the string over the head tube and back down to the other dropout. Tie the string down opposite the first knot. Take the ruler and measure the distance from the string to the seat tube on both sides. They should be roughly equal; if it is more than 3cm off, you've got a real alignment problem in the frame.

Dents are a mixed bag. On an aluminum frame, they're generally considered death, so walk away. On a steel frame, less so. If the dent has deformed the side of the frame tube opposite the dent, walk off. If it's close to a lug or joint between the tubes, walk off. However, dents in old steel frames does not always make them unrideable. It does, however, make them less valuable.

Some items can be stuck in the frame. One is the seat post. Another is the stem (this part holds the handlebars and connects them to the frame). Bring along a set of metric allen wrenches, and loosen the seat post bolt and stem. You may have to tap on the top of the stem bolt after you loosen it to free the stem. After loosening the bolts, see if you can move the stem and the post. If they are stuck, walk away. You may think you can get the post loose with some WD40 or PB Blaster, and you may be right, but you may not. Sometimes fairly drastic measures have to be used. Note that newer bikes use a different type of stem and headset ('Threadless"), and this advice may not apply on them. If unsure, walk off. But on older steel bikes, the classic quill stem is the most likely.

On to the headset. The headset is the part of the bike that allows the fork to turn. It is, after the rubber parts and cables, on of the most common parts of a bike to wear out. It needs to be properly adjusted. There is a simple adjustment test. Hold down the front brake and shove the bike back and forth, with the wheels against the ground. If you feel a click-click, the headset is too loose. Next, pick the front end of the bike up, leaving the rear wheel on the ground. The front wheel and fork should flop easily to one side or the other. If not, the headset is too tight.

If the headset is properly adjusted, turn the bars from side to side. If the you feel the headset bind at a point in the turn, this could mean the fork steerer tube is bent. Check to see if the binding is caused by an external factor (ie, a cable rubbing on the frame). If not, walk away. If the headset is not properly adjusted, ask the seller to adjust it. A too loose heaset can hide this problem.

Also, if you feel the headset seem to click as you turn it, this likely means the headset is worn to the point it needs replacement. Again, a headset that is too loose will hide this problem. Time to talk down the cost of the bike, at least by 75-100 dollars-- about what a shop replacement will cost. You can replace it yourself, but you'll have to buy some tools and a new headset, and that can become confusing.

Which brings us to the bikes nationality. Bikes are not all built to the same standards, and in particular on older bikes, you can run into national differences on parts. French bikes are pretty and ride beautifully, but the headsets on them are an obsolete threading and no longer made. Unless you really, really trust your shop, or actually know someone who knows the tricks of working on them-- and many shops don't have a clue in this regard-- if you're looking at a French bike with a damaged headset, it's probably time to walk away. Likewise, old Raleighs use a Raleigh specific threading. If you're looking at any old three speed that says "made in Nottingham" anywhere on it (Raleigh made bikes under many brand names) and appears to have headset issues, walk away. Older Japanese bikes used the old "Japanese Industrial Standard", headsets for which can still be found with some effort. A competent shop (or shade tree mechanic) can convert the JIS to the English standard-- but it will cost you some out-of-pocket cash, and requires specialized tools. Even more confusing, some bikes (USA made Raleighs in particular) used a mixed headset, with standard Cups and a JIS headset race. You're likely confused by now, and may understand some of the problems that can be associated with replacing parts.

While we're on the subject of threading, Motobecanes, some Peugeots, and a few other bikes used Swiss threading in the bottom bracket. Replacability is a huge issue. Your only replacement choice are the Phil Wood rings, which are, in a word, costly. Worth it for the high end, but not a beater. Talk down the price on Motobecanes in particular. (Oddly, some Swiss brands-- Mondia in particular-- used French threading. Go figure.).

Frame materials are another point, often used by sellers to pump up a bike. Unfortunately, tubing manufacturers made many different types of tubing, and seller will often confuse them, usually to their advantage. Look, first off, hi-ten means nothing. So does 2040 or 1020 tubing; although they can be on good bikes, they're refered to as "gas pipe" in the bike world. Reynolds 531 was a mainstay for a loooong time, so frames built of 531 tend to be pretty good. But there are a number of grades in 531, though, just to confuse you. Columbus made a mix of tubes, especially in the eighties. Columbus SL or SLX is prized. Ishiwata made some good stuff, as did Tange and Vitus. If in doubt, ask. I could write a dissertation on steel frame tubing, but it is too much for the purposes of this post. In general, Chro-moly beats hi-ten, and Reynolds/Columbus/Ishiwata/tange/Vitus puts the bike in at least the middle of the pack. Do not let a seller pump up the price of bike by extolling the virtues of Hiten or other more lackluster frame tubing, though.

Wheels are another matter. Like headsets, they often need replacement. Check that the spokes are tight and the wheels realtively true (they shouldn't wobble from side to side). Look for missing spokes. There are two types of true on a wheel-- radial (it is circular) and lateral (side to side), and many sellers only concern themselves with the latter. If you're riding a bike, and you feel a thump-thump in the wheel, and the tire is not flat, the wheel is likely out of radial true (the tire may not be properly seated, as well). If it wobbles, it's out of lateral true (or the hub bearings need to be tightened). If either one is far enough out, you may have to replace the wheel-- or at least have it trued by a competent mechanic. Again, down goes the price in that case.

Like frame tubing, there are so many makes and grades of rim and hub that I won't go into them here. In general alloy is better than steel. If a bike has steel rims (if you're in doubt, a magnet can tell you), it is not going to brake well in wet conditions. Maybe not at all. They're also heavy and can slow you down, and are usually the mark of a lower end bike. If someone is trying to charge you more than $150 for a bike with steel rims, my advice is to walk off. Even 150$ is a stretch.

This list is not meant to be complete. It is meant to help you assess a bike prior to purchase. Most CL sellers are honest, and may not know the bike's faults. In buying a bike here, you're on your own (unless you have a trusted friend who happens to know a great deal about bikes). In fact, if you have such a friend, take him or her along on a buying expedition. Bribe them with lunch or something.

If you think something is missing from this post, or something is insufficently clear, you can contact me via the email above. I won't, in all likelihood, reply, but I may edit or change the post. I'm particularly interested in simple methods to spot potential problems. There are certainly some problems with old bikes I could not cover here; I've tried to make sure the tools I recommended are easily available to the casual bike buyer. I believe they are metric allen keys, a piece of string, a ruler, and a magnet. An adjustable wrench would be good as well; some bikes don't use allen bolts for the stem and the seat post bolt.

If you'd like to repost this or save it, go ahead. Print it out, take it with you to a buy if you want to. If you want to put on another Craigslist, please, go ahead, but email me that you're doing it. I might not reply. I am interested in the viral nature of things, however, and for those of you likewise interested, this post started on the Richmond Virginia Craigslist.

Good luck,