How to Measure and Buy the Correct Bike

Buying a Road Bike

1. Buy a road bike if you plan to ride primarily on pavement. There are a lot of different types of road bikes available for different styles and functions. They are all, however, made for generally even, hard terrain like city roads or smooth trails. They are the most common bikes out there, and can be broken up into a few subcategories:

   1. Racing/Road bikes: Aerodynamic, fast, and light, these bikes are the most common road warriors. They have thin tires and lighter frames, and usually aren't made to carry extra weight. Components are built for speed on a variety of geography, from big hills to long flats.
   2. Cross bikes: These have wider tires and a sturdier frame, and are built for a variety of terrains, from city roads to bike paths and light trails. They are usually built to handle some weight, so they work well for commutes to work or the store and on short-range trips.
   3. Touring bikes: Made for long, self-contained trips, these bikes are sturdy, no-frills bikes that can take a beating and hold a lot of weight. Because of this, they also function well as commuter or city bikes.
   4. Triathalon/Time-Trial Bikes: Build for speed, these expensive beasts are light as a feather and have special handlebars that let you lean down for minimum wind resistance.

2. Know how to measure a bike's frame size. The main factor in buying the right bike is the frame size. The frame is the metal body of the bike, and it is measured in three key places. While most bike frames utilize only one measurement for sizing, knowing how to locate all three is key to getting the right size bike.

   1. Seat Tube: This is the vertical bar between your seat and the pedals. It is measured to the center of the crankshaft, which is the circular disk that your pedals attach to.
   2. Top Tube: This is the horizontal bar between your seat and the handlebars. It affects your "reach" towards the handlebars.
   3. Head Tube: This is the small vertical area on the front of your bike, measured between from where it begins to fork around your front wheel and the handlebar stem. It also affects your "reach" to the handlebars.

3. Measure your inseam. Stand with your feet six inches apart, and measure up to your pubic bone from the inside of your foot (where your leg meets your hip in your crotch). Take this measurement in centimeters, since all road bikes are measured that way.

4. Multiply .67 by your inseam measurement to estimate seat tube length. Multiply .67 by your inseam to find you suggested seat tube. If your inseam is 85 centimeters, for example, your seat tube should be 56.95, or 57, centimeters long.

   1. The seat tube is usually, though not always, measured from the top of the tube to the center point of the crankshaft.^[1]

5. Make sure you can stand comfortably with the top tube between your legs. You're going to hit the inevitable red light, and you need to be able to stand up with your feet on the ground while you wait. Straddle the bike and make sure that you can stand with both feet firmly on the floor. If you can't, you'll need to go down a frame size.

6. Try out a variety of bikes to determine your "reach." There are a lot of different formulas out there to figure out the right reach, but the truth of the matter is that everyone is different, and you need to find out what is comfortable for you. When trying out bikes, note the length of the top tube and head tub, as well as the length of the stem -- the smaller piece connecting the handlebars to the frame -- and write down the measurements you like in case you want to buy your bike online. A comfortable reach should:

   1. Let you rest your hands comfortably on the handlebars. Your fingers should be free to wiggle around.
   2. Keep you elbows slightly bent, not locked or pressed up.
   3. Allow you to reach all parts of the handlebars, especially gears and brakes, easily.

7. Know that comfort must always take precedence over measurement. The lengths of each tube may mean little compared to your final fit, since the angles the frame is joined at affects the distance between the seat, pedals, and handlebars just as much as the size. Studies have shown, for example, that a longer top tube can result in the same fit as a smaller one depending on the length of the head tube. These measurements are starting points as you go shopping, not perfect metrics for the right fit.

   1. Always ask to test out 3-4 brands of bikes, and try out a size above and below the one you measured for. Your personal geometry is unique, so you need a bike that fits you.

8. Buy a road bike with handlebars even to the seat height if you are just beginning. It is easy, especially with curved "drop" handlebars, to get your hands lower on the bike. While serious riders often prefect lower handlebars, those who struggle with flexibility or are new to biking almost always prefer a bike with handlebars even to the seat height.

   1. Flat handlebars are rare on road bikes, unless they are designed for cruising or casual riding. It is difficult to go long distances with flat bars.
   2. Drop bars are the classic, double C-shaped handlebars with two front-facing brakes and a variety of places to put your hands for comfort.

9. Purchase a "rack" if you plan on traveling or commuting with your bike. Bike racks allow you to pack things above your back wheel, but not all bikes are compatible with racks. In general, road bikes are not made to handle the weight of a rack, though cross and touring bikes are. Bikes that have two holes at the top of the "v" leading from the seat to the back wheel and two more hole in the very back of the frame will allow you to mount a rack.

   1. Panniers are bags designed specifically to clip onto a bike rack, and are essential if you are transporting a lot of goods or want to travel long distances.