After deciding that you want to buy a cheap bike, and deciding what kind of cheap bike you want, the next step is to find a bike that fits you. If your bike is too large or too small it won’t be comfortable or fun to ride.
Figuring out the right size bike is kind of like figuring out what size shoe to wear, only all the shoemakers and shoe sellers each have their own system of measurement. Most department stores try to simplify things by listing only the bike’s wheel size. That roughly translates into the bigger you are, the bigger a wheel you need. Not the most accurate method.
You will see frame sizes, if listed at all, use a variety of secret codes:
Relative size – small, medium, large
I’ve seen some small frames from one company that were larger than mediums from another.
Centimeters – Number of centimeters from top to bottom
Supposedly this is measured from the middle of the cranks to either the top bar or top of where the seat post goes into the frame. Either way these numbers seem to have a wide tolerance and/or variation.
Inches – Number of inches from top to bottom
This can be way confusing. On a recent trip to a department store I saw a 20 inch frame with 24 inch wheels. There was a couple there who had been told they should buy their daughter a 20 inch bike. They had no idea which scale they were looking at. The clerk from the gun counter wasn’t much help.
Standover Height – Number of inches from the top bar to the ground
This is a useful measurement if the bike has a level top bar. Many mountain bikes and commuter bikes now have sloped top bars so this measurement is meaningless. The point is that you need to be able to stand over the bike without damaging any external organs.
Top Bar Length – The distance from the seat post to the head tube.
Not often seen when describing cheap bikes. It is an indicator of how far you are going to have to reach or lean forward to hold the handle bars.
You’ll notice that all the measurements above deal with the frame and the wheels. This is because those are the things that aren’t changeable. Nearly everything else on a bike is adjustable. Seats can be moved up and down and back and forth. Handlebars can be raised, lowered, tilted or handlebar stems can be replaced for further adjustment. Even pedal cranks can be replaced with longer or shorter versions. This is how a wide variety of people can be shoehorned into a much smaller variety of bikes.
So how do you know what’s right for you? Go to stores and sit on a bunch of bikes. Researching numbers will do you know good until you learn how those numbers relate to your body.
So now you’ve brought home a bike and you need to make all those adjustments I mentioned above. Where do you start? It doesn’t matter because your first set of adjustments will be wrong so why worry about it? Make a rough guess, go for a short ride, change things. Do this over and over again till everything feels right. Do a search on the web on how to fit a bike. You will get a wide variety of tutorials that are all mostly correct. Remember that your comfort and happiness are more important than being correct.
This is where a bike shop can come in handy. Some will help you adjust your bike for a small fee. If you want to avoid the trial-and-error this can be well worth it. However, don’t pay for a fitting that costs more than your bike. Some computerized, motion-captured fittings can run into hundreds of dollars. Worth it if you’re training for the Olympics but not much use for the $79 dollar mountain bike from Wal-Mart.