There are many differences among cyclists. Preferences for one brand or another, colors, accessories, clothing and many more. But one of the most important differences, and in the case of beginners the least contemplated one, is that different body measurements and proportions require a different bicycle setup to fit the specific body of each rider.
This point is crucial for comfort and confidence. Confident cycling requires a perfect fit. Cycling evolves aiming to improve the performance of the rider. With that goal in mind, bicycle factories have been improving bicycle frames and components.

Today the market offers a wide variety of models and designs, so the biker can choose the right bike for his or her particular anatomy. And if you already have a bike, you should check its dimensions and, if necessary, correct seat height and/or stem or change any of its components. In short: do not adjust your body to the bike but instead, adapt the bike to your body.

 

The right size

All adult bikes are measured by their frame size. This is typically the length of the seat tube: the near-vertical tube that the saddle and seat post slides into. Manufacturers will measure these slightly differently. However, the rule of thumb is to measure from the centre of the bolt which fastens the crank arms, all the way up the frame to the top of the seat tube. Some brands (especially American) stop short of the top, only measuring to the point where the top tube meets the seat tube. And each frame height has a proportional length size.

Bike Frame Size

The best opportunity to get the right size bike is to buy it already knowing this. But if we already have the bike and we don’t have the fortune to be of the right size, it is convenient to do the necessary setup modifications to improve everything we can to have the best pedal position possible.

For example, if the bike is too short, we can put a longer stem. Or on the contrary, if we find the bicycle too long, we can get a shorter stem.
If we seek a more upright position, we will try to get a stem with a more positive angle and perhaps a shorter one.
But if we want to achieve a more aerodynamic position, we can resort to a longer and perhaps even zero angle stem.

The handlebar also allows some variations: a straight handlebar gives us a lower and more aerodynamic position, while a “dove” double-height handlebar gives us a more upright and relaxed position.

And finally, we can modify the “front-rear” saddle position, depending on wether we want to get closer or move away from the handlebar.

Another thing you can check is the following: in standing position, with the bicycle between the legs, there should be about 3-4 inches of space between the horizontal tube and the groin. This will ensure that our intimate parts do not suffer in case of a sudden dismount, which are not uncommon in mountain biking.

For those who have not been fortunate enough to experience different bike setups and sizes, do not follow blindly the advise of the vendor or an acquaintance. Instead, borrow different bikes from fellow bikers to test several frames. Do some forced maneuvers, such as pedaling in very closed circles, or down a ladder, or bend abruptly in a curve.

Hint: in the case of mountain bikes, the smaller the frame, within the maximum and minimum of your possible sizes, the more maneuverable the bike becomes.

The saddle

There is a simple formula to put the saddle in the right height. In relaxed pedaling position, the knee should be slightly bent when the pedal reaches the lower part of the circle; this with the foot properly supported (the widest part of the foot must be on the axis of the pedal). If while pedaling you feel the hips sway, this indicates that the seat is too high.

It’s worth mentioning that when you are doing some long descent you should drop the seat height slightly to facilitate the movement of your center of gravity) and return it to the correct position when the descent is completed.

Another aspect to take into account about the saddle is the angle position. The correct angle is when the saddle is parallel to the floor.
If the saddle is pointing downwards, you will inevitably roll forward if you don’t make an extra effort to keep balance.
If instead you point it up, the problem may be worse since studies have shown that this seriously affects the male reproductive organs.

The saddle size is directly related to the position taken by the body on the bike. You must not be afraid of narrow saddles, because a  proper riding position requires that your weight is distributed between the saddle, pedals and handlebars. Thus, when bringing the body slightly forward the bottom part the does not need complete support. If in that position you had a wide saddle, your thighs would touch the sides of the seat with consequent discomfort.
On the contrary, on a bike ride where the position is more upright more support will be needed from the saddle.

The handlebar

The handlebars should be about 1 to 2 inches below the seat on a mountain bike. Too much weight on the saddle unnecessarily recharges the buttocks (on a saddle not suitable for this position) and column.

Many modern mountain bikes require the rider to stretch far forward (very long and narrow angle stems). This distributes the weight evenly on both rear and front wheels to improve the aerodynamic position, and it also helps to climb more easily when standing on the pedals.

If this is not the activity that you aim, to adopt a more upright position simply change to a shorter or higher angle stem, always remembering to distribute the weight between front and back, and keeping a relaxed position.

The width of the handle is usually too long and it may be necessary to shorten each end. Experts say that the width should not be less than the width of the shoulders. If it is too narrow, you will be pedaling with a closed thorax, oppressing the alveoli and preventing aero pulmonar capacity.

Following with the bio-mechanical advice, it is essential that the elbows are always flexed and relaxed, allowing the arms to work as a buffer. All impacts and vibrations from the floor are absorbed, thus avoiding to resent the back.

Body and machine

A correct cycling position directly influences comfort and drastically reduces the potential aches and pains the following days. It also helps expanding the chest thus improving breathing.

Remember that the mountain bike was built with the intention of giving the rider the ability to face the toughest and steepest roads. And even though everyone can set it up to their own taste, it’s always healthier to follow some standards.

The correct position is determined by the uniform distribution of the body weight between the handlebars and the saddle, and the comfortable and relaxed posture of the arms.

The versatility of the mountain bike will allow you to enjoy many adventures. Although you will have to train, have a proper nutrition and a perfect fit on your bike to achieve the best results and enjoy your ride.

Have fun!