You and your bike should fit well together whether you are a serious cyclist or just out for some recreation. Minimizing discomfort, increasing efficiency and preventing pain and injury are all benefits of a proper fitting bike.
A few things to consider when fitting a bike:
Frame size/height of the top tube
On a properly sized bike you should be able to stand over the top tube with your feet flat on the ground (Fig. 1) and still have enough room to comfortably lift the bike a short distance off the ground (Fig. 2).
Fig. 1 and Fig. 2
For mountain bikes or other off-road bikes you generally want more space between you and the top tube (2-3 inches or more) to minimize the chance of injury when stepping off the pedal on uneven ground.
Proper seat height is important for comfort and efficiency and to help avoid unnecessary stress on your joints.
- If your seat height is correct your knee should be slightly bent when your foot is at the bottom of the pedal stroke (Fig. 3).
- If you rock in the saddle while pedaling or find yourself reaching for the pedal at any point, your seat is too high.
- A seat that is too low can cause joint discomfort and rob you of power as you pedal.
- Adjustment - One way to set seat height is called the “Heel method” (Fig.4):
Fig. 3 (knee bend) and Fig. 4
- Sit on the bike as if riding. To do this you will need to find a place you can safely steady yourself and preferably have someone help you hold the bike upright.
- Place your heels directly over the axles of your pedals and spin backwards slowly.
- At the bottom of the pedal stroke you leg should be fully extended with your heel barely touching the pedal. If this is not the case you will need to step off of the bike and adjust the seat height accordingly.
- Repeat this process until you find the correct height.
Note: No two riders are the same; if you find that this is not a comfortable riding position you can try adjusting your seat height. It is important to do this in small increments (approximately ¼ inch at a time). Make sure to spend some time riding after each adjustment to test the new position, a simple spin around the block may not be enough to decide if you have found the correct seat height.
A bicycle seat can be adjusted for angle and forward or backward. A level and properly positioned seat places the majority of your weight directly on the sit-bones.
- Angle - In general your seat should be level with the ground. Tilting the seat too far forward will cause you to slide forward while riding placing additional stress on your hands, wrists, arms and shoulders. Tilting the seat too far backward can cause pressure on the soft tissue on the forward part of your pelvis and also make the bicycle difficult to control.
- Adjustment - Start with a level saddle and make very small angle adjustments as needed.
- Position - Distance between the seat and handlebars can be adjusted by sliding your seat backward or forward.
- Adjustment - For a general idea of where to position your seat, place the back of your elbow against the nose of the seat and reach your fingers out to touch the stem (Fig. 6). If your fingers touch near the center of the stem this is a good starting point.
- Again, seat adjustment depends on the rider and the type of riding you intend to do. After initial setup make small adjustments to find the position that is most comfortable for you.
Comfort should be the deciding factor for handlebar height. Try to strike a balance that distributes your weight comfortably between your arms and the bike seat. Handlebars that are set too low can cause increased strain on your neck, back, shoulders, arms and hands. If the handlebars are set too high the majority of your weight will be shifted to your seat which may also cause discomfort. When adjusting handlebar height do not exceed the safety height marked on your stem.
Photos and information provided in collaboration with the MSU Bike Shop.
Visit them at: http://bikes.msu.edu/
Helmets are Essential:
Before riding make sure everyone is wearing a safe and properly fitted helmet. Helmets only work if they are in good condition and you wear them correctly.
- Safe helmets will have a seal of approval from safety organizations such as ANSI, Snell or CPSC.
- A properly sized and fitted helmet should sit securely on your head and not rock or sway as you move around. To make sure you are wearing a correctly sized helmet, try the Eyes-Ears-Mouth check:
- The helmet should fit one to two finger widths above the eyes. When you look upward the front rim should be barely visible to your eye. A helmet worn too far back will not protect your forehead.
- Make sure the straps of the helmet form a “V” under your ears when buckled.
- The chin strap should be snug against the chin so that when you open your mouth very wide you feel the helmet pull down a little bit.
- Helmets come with interchangeable pads to help you adjust the fit both front to back and side to side. Try the different thickness pads until you find a snug fit that is comfortable without being too loose.
- Helmets are not indestructible; they are designed for a single incident. If you are in an accident or your helmet sustains an impact or is damaged in any way (e.g. scrapes, dents, or cracks) you should throw it away and get a new one. It is important to note that damage is not always visible.
Proper bicycle maintenance:
It is very important to keep your bicycle in good working order. You should have your bike thoroughly checked by a professional at the beginning of your riding season to ensure that it is in good mechanical condition. A more general check should also be performed at the beginning of each ride:
- Are your tires in good condition and properly inflated?
- Are your handlebars, wheels and seat straight and secure?
- Are your brakes working properly?
- Are there any signs that the bike may be damaged or in need of repair?
Riding bicycles is a great way to stay active. Being prepared with the properly sized and maintained equipment will help make the experience safer and more enjoyable.
If you have any further questions about bicycle and helmet fit or safety, check with your local bike shop, club or organization, they can be great sources of information for safe cycling.