Make the bike fit your body. Do not force your body to fit the bike.
Measure the length of your inseam to the floor with bare feet placed aprox 15 cm apart. Then multiply the number with 0.61. This Bike Fit result is a recommended size of a road bike frame to you, measured from the centre of the crank shaft through the seattube and up to the center of joint with the top tube pibe (on bikes where the top tube is horizontal !).
If your current or your desired road bike frame has a slope top tube, you should find the center of the joint on front tube and the top tube and measure a horizontal line to the middle of the seat tube pipe. From this point and down to the centre of the crank shaft shows you the size of the bike frame.
If the top tube is horizontal you can do a double check. The distance from the top of the seat-tube up to the saddle should be approx 10-13 cm when the saddle is set at the correct height. When the pedal arms are horizontal and you have clicked into the pedals wearing cycling shoes your knees should be at the top tube when you squeeze them together and the pedal shaft should be in a vertical line below your knees.
Fit the Saddle height on the bike:
You can find different methods to calculate this crucial bike fit distance. We recommend this method.
Begin the bike fit by standing on a hard surface without shoes on and your feet aprox 15 cm apart. Use tape to help you and measure from the floor to your inseam and push with the same force as a saddle does. Multiply this figure by 0.883. The result is your saddle height, measured from the centre of the crank shaft along the seat tube and to the top of the saddle.
Add 2 or 3 mm to this road bike fit calculation if you have long legs compared to your height. If you suffer from knee pain caused by damage to the back side of the kneecap adjust the saddle a bit higher. But it should never be so high that your hips bobbing over the saddle when you pedalling around. If this formula results in a big change from your current settings you must move your saddle 2-3 mm per week until you reach the new position to avoid any injuries.
The saddle height is based on a crank arm length of 170 mm. A little further down in this article are recommended crank arm length based on the length of your inseam. Adjust your saddle height in relation to whether you are using longer or shorter crank armd than the 170 mm which is based on this calculation.
Fit the Handle bar on the bike:
The width of the handle bar must match your shoulder width to open your chest so you improve your breathing. A bit too wide is better than a little too narrow. Make sure that the bending of the handlebar is large enough for your hands. Modified "anatomic" bending may feel better for small surfaces.
Fit the Brake levers on the bike:
Place them to bring you the best compromise between the hand position on top of the brake lever, braking and when your hands are placed in the bending. Most riders will cope best by taking a ruler as an extension of the flat bottom of the handle bar and place the end of the brake levers down to the ruler. The brake levers do not need to be placed symmetrically, as it is your comfort that counts. Personally, I have always put my brake levers a little higher because I think I had better access to the top of the brake levers when I had to accelerate on smaller hills.
Fit the Height of Ahead set on the bike:
Measuring of both the bike and yourself must take place.
Start by placing the stick a little high, approx. 2-3 cm below the top of the seat measured in a horizontal line. This should give you comfortable access to any position on the bike. As time goes by, think about lowering the stick up to 2 cm in order to achieve an improved aerodynamics. This should be done gradually approx. ½ cm at a time. If your lower back or neck starts to hurt, then go up again.
The purchase of a new bike with Ahead Set you should not cut the fork to start with. With "spacers" at ½ -1 cm thick, you can carefully move the stick a bit up and down until you have found the perfect setting and then cut the fork at the desired length.
Fit the Length of top tube and Ahead set on the bike:
As a rule of thumb you should expect that your Ahead set should be between 100-130 mm. An Ahead set beyond this length should only be considered if you are particularly high or low. A very long Ahead set impair your ability to control the bike especially in turns and a short Ahead set can be outright dangerous at high speeds, since the length provides stability at higher speeds!
Most riders sit comfortably when hands are placed on top of the brake levers and elbows are slightly bent. In this position you must be able to see the front hub of your front wheel behind the handle bar. Otherwise, the road bike frame is too short!
The combination of these two dimensions determine the reach. Depending on your anatomy and flexibility your reach can be long for better aerodynamics, or it may be shorter for more comfort, especially for your neck and lower back.
Fit the Length of Crank Arms on the bike:
Based on the length of your inseam:
- Less than 69 cm, use 165 mm crank arms
- Between 70-82 cm, 170 mm crank arms
- Between 83-86 cm and 172.5 mm crank arms
- Longer than 86 cm, 175 mm crank arms
The length of a crank arm is measured from the center of the crank fixing bolt to the center of the pedal fixing hole. The length is usually stamped on the back of the crank arm. If you use the crank arms longer than recommended you will be able to push higher gears, but will lose the speed of your pedalling. In some cases the large gears can course injuries to your knees. With shorter crank arms you will improve your short sprint skills but still loose a little to your top speed.
Fit the Slope of Saddle on the bike:
Saddle should be adjusted so it is horizontal and you can check it by putting a yardstick on the top of the saddle and compare it with something horizontal as a table or a window sill. A small downward slope may be more comfortable but be careful. More than a degree or two can cause you to push a little forward and force more pressure on your arms hands and front and will degrade the ability to manage the cycle.
Fit the Front and Rear Position of the Saddle on the bike:
Sit comfortably in the middle of the saddle click in the pedals and put the one crank arm horizontally. Keep a stiff long stick on the front of your kneecap. For most of us the stick should touch the end of the crank arm. This is known as the neutral position. You can also measure mark the knee position on the top tube with tape. Get off the bike and a stiff long stick should be near vertically placed from the tape to the end of the crank arm.
By correcting the saddle loosen the saddle nut so you can gently slide the saddle to the correct position. Some Time Trial Riders like that line 1-2 cm behind the end of the crank arm to increase the ability to go in higher gears. In contrast criterium and road race riders should have a position a little further ahead in order to achieve faster pedalling.
Remember if your saddle is fixed at the wrong spot you must start making corrections from the middle of the saddle measured in a straight line from the saddle tube and adjust as recommended.
Fit the Feet placing on the bike pedals:
Some of us walk as doves others like Charlie Chaplin. Your gait disclosed when you leave a pool of your wet footprint or when you take a walk in a muddy forest. You protect your knees when cycling when you put your cleats as close to the natural angle of your feet as possible. This is easy with the many good pedal systems available today as you can turn your feet freely from side to side several degrees before release occurs.
Then all you have to do is to set the clamps at the correct front and rear position. Simply place them so your widest part of each foot is centred over the pedal axle. If you experience discomfort, such as the numbness or burning (especially on long sessions) then move clamps back a bit, sometimes as much as a whole cm.