Each type of bicycle is designed to adapt in a very particular way to a rider. Seat, pedal, and handlebar positions are important for a more comfortable ride. If you want to buy a bicycle, we will provide you with all the information you need to get the most suitable one for you. If you already have a bicycle but it is not suitable for your dimensions, we will show you the adjustments that you must make. Check out the next steps to get started.
Part 1 of 3: You need to have a good understanding of the use of measurements
Step 1. Learn the guidelines
Now that you have the measurements of the seat tube, you must understand how these correspond to the general sizes of the bicycle. Different companies usually vary these measures a bit, but here are the basics:
- Size XS: from 33 to 35 cm (13 to 14 inches), usually for those between 1.52 m (5 feet) and 1.62 m (5 feet 4 inches)
- Sizes: 35 to 40 cm (14 to 16 inches), usually for those between 1.62 m (5 feet 4 inches) and 1.7 m (5 feet 7 inches)
- Size M: 40 to 45 cm (16 to 18 inches), usually for those between 1.7 m (5 feet 7 inches) and 1.77 m (5 feet 10 inches)
- Size L: 45 to 50 cm (18 to 20 inches), typically for those between 1.77 m (5 feet 10 inches) and 1.83 m (6 feet 1 inch)
- Size XL: from 50 to 55 cm (20-22 inches), usually for those taller than 1.83 m (6 feet 1 inch)
Step 2. Know your ideal position
Sometimes the numbers aren't the most important thing (actually, they never are). What is important is always the feeling that the bike gives you. Your body should be as follows:
- Arms. The shoulders should be relaxed and the elbows slightly bent.
- Chair. Your heel should just touch the top of the lowest pedal with your straight leg. Make sure the crank is right at the bottom of its travel.
- Knees. With each pedal at the bottom of its travel, make sure your knees are slightly bent.
- Gear lever and brake lever. Don't just leave them as they are. Experiment by moving them further or tilting them.
Step 3. Learn how bikes vary
Sizing systems vary not only between companies, but also between bikes. If you are looking for your next jewel on the Internet, keep in mind the following basic concepts:
- Generally, sizes for road, cyclocross, and hybrid bikes are 3-4 inches (7-10 cm) larger for the same rider height, as in the table above. If you are looking for one of these, make the necessary adjustments.
- Hardtail bikes and full suspension bikes are the same size. The main differences are the cost and the type of roads on which they can be driven. Full suspension bikes have better shock absorbers and can withstand more aggressive riding. However, hardtails are more versatile, light and commercial.
Part 2 of 3: Measure your height and that of your bike
Step 1. Measure your inseam
To find the best bike size for you (the seat tube length you need), start by measuring your inseam. To make it:
- Stand up straight and place your back against a wall. Place a book between your legs as if it were a bicycle seat.
- Use a tape measure to calculate the distance between your crotch and the floor.
- Multiply that number (in inches) by 0.67. Subtract 4. That's how long the seat tube should be.
If you have a frame in C-C, multiply it by 0.65
Step 2. Measure the seat tube of your bike, if necessary
If you already have a bike, you need to know if it is the right size for you. Here's how to measure your frame:
- Find the top of the seat tube (the point where the seat clamp meets the post).
- Measure from that point to the center of the shaft that joins the crank arms.
- That number is the length of the seat tube. Check if it matches your ideal size. Take a look at the basic measurement system below if you are thinking of buying a bike.
Step 3. Perform the height-to-base test
This is a fairly generic test to check if the bike is at the correct height for you. The number you got by measuring the distance between your crotch and the ground should be about 2 inches (5.1 cm) more than the height of your bike at the top tube (the one that goes from the seat to the handlebars).
To run this test, place your leg on the top tube of the bike and ride on it. For a mountain bike, ideally there should be about 2 inches (5.1 cm) between your crotch and the top tube. Make sure to wear cycling shoes
Step 4. Find your ape index
Once you know the proper height for your bike, you have to figure out where the handlebars should be for your particular torso length. You need to find your "ape index" to determine if you have a long or short range.
- Measure the reach of your arm (from one fingertip to the other) and subtract your height from it. A positive ape index (when your arm's reach is greater than your height) means that you should consider the next largest size. A negative ape index (your height is greater than your arm length) means that you should consider the smaller of the two sizes.
- This is a great indicator, especially if you are in the middle of sizes. Height and inseam should be your two main considerations in finding the right size.
- If for some reason you still have doubts, look for a smaller bike. It is easier to get a small bike than a large one.
Step 5. To get a specific size, find the ideal length of the top tube
This is done by measuring the length of your torso and the length of your arm. Here are the specifications:
- Stand up straight and place your back against a wall.
- Measure from the knuckles to the clavicle.
- Measure from your crotch (same place as before) to the hollow at the base of your neck.
- Add the results and divide by 2.
- Take that number and add 4. This is the ideal length for your top tube.
To clarify, let's say your arm length is 24 and your torso length is 26. So 50/2 = 25. Then 25 + 4 = 29. Your top tube length should be 29
Part 3 of 3: Adjust the bike
Step 1. Adjust the seat height
Adjust the length of the seat tube with your measurements. You will need a tape measure and a wrench. Here's how to do it:
- Place the end of the tape measure where the pedal handle connects to the bike.
- Stretch the tape measure to the calculated seat height using your crotch.
- Use the wrench to loosen the screw holding the seat post.
- Pivot the seat post up or down to the proper position.
- Use the wrench to tighten the screw.
- Adjust the seat so that the lowest point of the chair is level with the top end of the tape measure.
Step 2. Adjust the handlebars
Loosen the screw at the base of the handlebars. Use the wrench to turn left. To adjust the handlebars:
- Lean as far forward and down as you can on the handlebars (without making yourself uncomfortable). It is best to assume the position naturally.
- Raise or lower the handlebars to the position that is most comfortable for you.
- Tighten the handlebars. Use the wrench to tighten the bolt around the stem of the handlebar.
Step 3. Adjust the seat tilt
Your chair must be completely level. Very few people prefer to have the seat tilted up or down, but most drive best with the seat level. You must keep two things in mind:
- Tilt the chair up or down so your pelvis is level when you sit down.
- Tilt the chair so you don't slide forward or backward while sitting.
Step 4. Test the fit
You wouldn't buy a car without first taking a ride to test it out, right? You shouldn't rotate your hips, stretch your arms, lean to one side, or feel even a little uncomfortable. Here's how to test your bike:
- Sit on the bike with your shoes on. Your hips should be straight and facing forward.
- Position the pedals so that one of the pedals is at the lowest point of its rotation. The pedal will be as close to the floor as possible.
- Place one foot on the bass pedal. Your knee should bend slightly. Your heel should rest on the pedal.
- Lean toward the handlebars, keeping your elbows slightly bent.
- If you are not 100% comfortable, readjust the bike as needed.