Bicycling is a tremendous physical activity that allows you to get low-impact exercise and experience the calming effect of interacting with nature. Bicycling is ideal for everyone from professional, high-intensity athletes, to individuals who need a light workout for rehabilitation. The perfect bike fit is vital to ensure that all riders can enjoy riding their bicycle efficiently and in comfort. Here are some factors to consider when asking, what size bike should I get?
What Size Bike Should I Get?
The first question you need to consider when determining bicycle fit is what kind of riding do you intend to do? Are you an aggressive rider or a casual rider? Do you intend to ride off-road or on-road? Do you have any issues that prevent you from swinging your leg over the bicycle? The perfect bicycle exists for every rider, but taking a few moments to consider your cycling objectives is critical to getting the perfect bike.
No matter what your riding style, there are several key concepts consistent for all bike fits. Sometimes you need to go through the whole process of fitting a bicycle to determine the perfect frame size.
Many individuals mistakenly purchase bicycles with frames that are too small. The first test when selecting a bicycle is to stand flat-footed over the bicycle and place one hand on the seat and one hand on the handlebars. Gently lift the bicycle so that the top tube remains parallel to the ground. The ideal bicycle has somewhere between a half inch and two inches of clearance between your groin and the top tube. If you do not clear the top tube when standing flat-footed, the bicycle is too big. If you have two or more inches of clearance, the bicycle is too small.
Once you have selected the correct frame, you can consider the seat height. The correct seat height results in an almost full extension of your leg when the pedal is at the bottom of the pedal stroke. If you find yourself reaching for the pedals at the bottom of the pedal stroke, your seat is too high. If there is a large bend in your knee, the seat is too low. Minor adjustments to seat height can have a major impact on riding comfort. Always mark your seat post position before adjustments and don't adjust your seat more than a quarter inch up or down at a time.
Place your bicycle on a trainer and ensure that the front and rear wheels are level. Mount the bike and spin the pedals a few times to settle into a comfortable position. When you are in a comfortable position, halt your pedal stroke when your cranks are parallel to the ground. Take a plumb line and measure the relative position of your knee to the pedal axle. Your kneecap should be directly over the pedal axle with the crank parallel to the ground. Move the seat backward or forward to ensure proper alignment. If you cannot achieve the proper alignment, start over with a larger or smaller bicycle frame.
You cannot adjust reach until you have the right fit on standover height, seat height, and body position. To measure reach, leave the bicycle on the trainer and get into a comfortable riding position. When looking down at the handlebars, the stem should block out your view of the front axle. If the stem visually aligns behind the axle, you need a longer stem. If the stem extends beyond the axle, you need a shorter stem. You can also choose a positive or negative incline to the stem based on your personal preference. A negative incline is a more aggressive riding position, a positive is a position of comfort.
Fit Variations Based on Bicycles
There are subtle variations in fit required for different types of bicycles. Some bicycles are designed to have you more upright for better handling, some bicycles require a stretched out fit for better aerodynamics. The positioning of your knee over your pedal axle is consistent for all upright bicycles. More aerodynamic positions are less comfortable, but your body will adapt to the position. If you begin to develop chronic pain or numbness while riding, consider making adjustments to your fit.
Some common bicycle types are:
Road bicycles with drop bars give you the greatest variety of riding positions. The curved handlebars allow for an aerodynamic position, and a more upright position when riding with the hands on the hoods. "Wood chipper" style handlebars allow for a wide grip similar to a mountain bike. Road bikes are a good selection for paved trails and are ideal for casual or endurance riding. The wide variety of riding positions allows riders to switch positions frequently and avoid discomfort.
Mountain bicycles have wide handlebars for greater maneuverability at lower speeds. The riding position is more upright. Many cyclists who ride mountain bikes install bar ends on their handlebars to give them a greater variety of riding positions. Achieving an aerodynamic position on a mountain bike requires dropping the torso.
Cruisers have a more fully upright body position than mountain bikes. These bicycles are ideal for comfortable riding at low speeds. Many cruisers come with a step-through frame design for individuals who have problems swinging their leg over the bicycle. Cruisers are not used for endurance riding and are best suited for low speed riding for less than an hour. Cruisers are ideal bicycles for light rehab.
Triathlon bicycles require the most complex fit. The riding position must be fully aerodynamic. Aero bars allow the rider to stretch out on the handlebars almost as if they are laying down. With a triathlon fit, it is good to set the handlebars a little high on the initial fitting. As the rider gains flexibility, the handlebars can be dropped to achieve greater aerodynamics. Do not drop the handlebars so low that the rider position inhibits breathing. At the highest level of competition, riders make frequent minor adjustments to fit depending on their fitness level and the demands of the course.
The Difference Between a Man's Bike and a Woman's Bike
A man and a woman of the same height require different bicycles to achieve a proper fit. Women tend to have more of their height in their legs with shorter torsos than men. The result is that the reach for women will be shorter than on a bicycle for a man of the same height. Most bicycle manufacturers now have women's specific design model bicycles in their product line. A step-through frame is no longer an indication of a bicycle frame designed for a woman.
The shorter reach required for a woman's bicycle can lead to an overlap between the pedals and the front wheel when turning. Bicycle manufacturers have addressed this issue in a variety of ways. Some bicycle manufacturers elect to provide their women's bicycles with a smaller front wheel that improves the clearance between the pedal and the wheel. Some manufacturers have used bicycles with smaller than standard wheels on both the front and back, for example, a six hundred and fifty-centimeter wheel rather than the standard seven hundred centimeters.
For a woman to assure she has the perfect bike fit she must keep two things in mind during test rides and the fitting process.
The problem with the fit for all women's bikes comes with the reach. Once the seat height and body position adjustments are perfect, check the reach. If you have to stretch to get to the handlebars, you should insist on a shorter stem. A reach that is too long can result in discomfort and can inhibit breathing. Long reach can also lead to safety issues as it can be difficult to reach the brakes. A shortened stem is an effective solution, but a bicycle is more stable if it has at least an inch of stem length. If a bicycle requires a stem shorter than an inch for reach, consider a smaller frame.
Smaller frame designs, and women's specific designs can lead to toe overlap when turning. Toe overlap happens when you turn the front wheel and it impacts with the toe of your extended foot. Toe overlap can happen on men's bicycles too for men with large feet, or men who place their pedal cleats all the way back on their riding shoes. Minimal overlap is acceptable for riding, but experiment making wide turns when taking your bicycle on a test ride so you are aware of any potential issues before purchasing.
Signs of a Poor Fit
If you begin to develop chronic aches and pains that go beyond the general exhaustion felt after a long ride, you should consider some fit adjustments. You should be able to fit your bicycle so that you can achieve a comfortable and pain-free riding position. Indications that there might be an issue include:
If you develop knee pain, it is probably because your seat is too low. A low seat creates an inefficient riding position that puts undue stress on your knee joint. Raise your seat about a quarter of an inch at a time and take experimental rides until you find the perfect seat height. If knee pain persists, try to concentrate on riding in lower gears with a higher speed cadence to reduce knee stress.
Ankle pain comes as a result of a seat that is too high. Your Achilles becomes stressed by having to reach for the pedal. To correct ankle pain, drop your seat a quarter inch at a time and do test rides until you find the perfect seat height.
Finger numbness is the result of a reach that is too long. A long reach requires you to put more stress on your fingers. You can put on a shorter stem to reduce finger numbness. A more upright riding position from a stem with a positive incline can also reduce numbness.
Back pain can be a culprit of reach, or it can be a body position issue. If you have back pain, make handlebar adjustments so you are in a more upright position. If problems persist, consider changing your saddle. Typically a saddle should be level, but a minor decline might help achieve a more comfortable position.
Achieving the Perfect Bicycle Fit
Bicycles have a huge capacity for adjustment to ensure that everyone can achieve the perfect fit. Most bicycle manufacturers offer frame sizes in tiny increments to accommodate the needs of every body type. Variations exist in terms of tire size, stem length, crank length, and seat post height. When selecting a height, start by finding a frame that allows you clearance when standing flat footed over the bicycle. If you cannot clear the top tube of a bicycle while standing flat-footed, the bicycle frame is too big.
Selecting the perfect bicycle requires putting the bicycle through the fitting process. You must assure that the standover height, seat height, and reach can all be adjusted to accommodate you. Different types of bicycles, and bicycles from different manufacturers use frame geometry that can vary greatly. Don't be discouraged if you don't find the perfect fit. Keep trying different sizes, styles, and manufacturers until you discover the perfect bicycle for you.