Bike fitting guide: how to fit a road bike for the correct cycling position

Fitting a road bike can be a complex process, but it is essential for your biking experience.

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This bike fitting guide will walk you through all the steps involved in adjusting your bike for a custom fit. 

A bike fit evaluates a rider’s interactions with their bicycle with the basic objectives of lowering the risk of injury, maximizing efficiency, and providing the rider with comfortable and safe rides.

Individual riders may have slightly different objectives because more competitive riders may prioritize performance or efficiency, while recreational riders may be more focused on comfort.

Therefore, the bike fitting process should begin with some level of self assessment. 

What type of riding are you planning on doing? Are you looking to get into touring or racing? Are you new to biking?

Answering these kinds of questions will help in perfecting the fit. If you want to start racing, you’ll need a fit that will give you greater aerodynamic advantage.

However, if you’re interested in touring or are new to cycling, it’s best to have a more comfortable fit that will ease the strain of riding on your back, neck, and shoulders.

Here’s what you need for a bike-fitting exercise:

  • A bike that is the correct frame size for you
  • A stationary trainer on your bike
  • A multi-tool or an Allen wrench for adjusting the seat height, and to move your saddle front or back
  • A plumb bob to determine the correct saddle fore and aft positions. A plumb bob is a string with a weight tired to the end.
  • And finally, a friend to help with the fitting or an expert bike trainer to help you make the adjustments you need.

Optional: You may also need a video recording, since it’s not always best to rely solely on your feelings and not everyone has the same level of self-awareness of body posture and motion.

Bike fitting basics

Fitting a bike is a sequential process, which involves adjustments to these contact points; saddle, handlebars, pedals, and cleats. We discussed all the processes on how to fit a road bike. 

Below are some of the key components of a basic bike fit, we will discuss each component in more depth later.

  • Frame Size: the right frame size for a rider is determined by their height and inseam length, which are compared to the bicycle’s standover height. 
  • Saddle Height: This is the height of a bike seat, and it’s determined by the rider’s inseam. The wrong saddle height can cause knee pain. 
  • Saddle Fore/Aft: This is the position of the saddle relative to the pedals. The saddle should be at a position where the center of the knee is over the center of the pedal at the 3 o’clock position.
  • Handlebar Reach: this is how far you have to reach the handlebars from the saddle. Handlebar reach is adjusted from the bike stem. 
  • Handlebar Width: the handle bars should be as wide as the shoulders.
  • Cleat Position: it should be positioned such that the ball of the foot lies directly over the pedal axle. 

Finding the right bike frame size

The first step to getting a good-fit bike is to purchase one with a frame size that fits you.

This is a crucial step because if the size of your bike frame isn’t right for you, it will be impossible to get it to fit you, and no amount of adjustments will fix that.

So, first things first, how do you find the frame size that’s right for you?

You should know that road bikes come in different sizes, however, similar sizes from different brands don’t always have the same fit. This is because every bike brand has its unique set of bike designs and frame measurement. 

There are bike charts that aim to give you an idea of what bike frame is right for you (like the one below), but these are only rough estimations and often not 100% accurate because frame sizes differ for each brand. 

Height in cmHeight in feetFrame sizeBike size
147–152 cm 4ft 10in–5ft47–48 cmXXS
152–160 cm 5ft–5ft 3in49–50 cmXS
160–170 cm 5ft 3in–5ft 7in51–53 cmS
170–175 cm 5ft 7in–5ft 9in54–55 cmM
175–180 cm 5ft 9in–5ft 11in56–58 cmL
180–188 cm 5ft 11in–6ft 2in59–60 cmXL
188–196 cm 6ft 2in–6ft 5in60–61 cmXXL
196 cm+ 6ft 5in+62–63 cm XXXL
Road Bike Size Chart

Without relying on the frame chart alone, you can check if a bike frame fits you with this simple test. Find the clearance between your crotch and the top tube (highest bar on the bike frame). 

To get this measurement, stand over a bike and check that there is 1 to 2 inches (2.5 to 5 cm) of space between the top tube of the frame and your crotch.

When measuring standover height, be sure to wear your cycling shoes because they increase the total length of your legs. 

Ideally, you should have 1 to 2 inches of space between the horizontal top tube and your crotch on traditional bike frames. For bikes with sloping top tubes, look for at least 2 inches (or more) of clearance.

Check the standover height: if you’re shopping online for a bike, a simple calculation can help you determine the clearance between your crotch and the top tube.

This is done by subtracting a bike’s standover height from your inseam length. 

In this context, inseam length is the distance between the floor and your crotch, and the standover height of a bike is the distance between the ground and the top of the highest tube on the bike frame. 

Check the specified standover heights and then compare it to the length of your inseam. The difference between the standover height and your inseam gives you the clearance. 

For instance, if you measured your inseam to be 27 inches, a bike with a standover height of 26 inches will be a good fit. In this case, the clearance is 1 inch. 

Your inseam (27”) – The bike’s standover height (26”) = 1 inch clearance. 

How to measure your inseam

  • Get a tape measure, pencil, and a thick hardcover book. 
  • Wear your cycling shoes and stand against a wall.
  • Place the book between your legs, make sure it’s snugly nestled against your crotch 
  • Use the pencil to mark the spot where the top edge of the book meets the wall
  • Measure from the mark on the wall to the floor. This is your inseam length.

Adjusting the saddle height

With the frame size out of the way, next is to find the perfect saddle height for you.

Bike saddle height

Finding the proper saddle height is a core part of bike fitting, and it’s often the first adjustment in the bike-fitting process. 

Keep in mind that a bike seat that’s too low or too high will cause you pain and discomfort, which will eventually lead to injuries.  

To find the perfect bike saddle height;

  • Get on your bike with your riding shoes on and sit on the saddle.
  • Put the pedals in the 6 0’clock position, so your pedals are vertical to the ground. 
  • Now watch the leg on the lower pedal and check for a slight bend in the knee. 

If your knee is too bent, it means that your saddle is too low, and if your knee is locked in, then it means that your saddle is too high.

Riding in this position will put a strain on your pelvis and back, causing pain and saddle soreness. And if your saddle is too low, you will lose power and experience knee pain. 

Note: it’s important to wear your riding shoes while fitting your bike. And you may need a friend to help with holding your bike and watching your knees. 

Choosing your preferred saddle type: bike saddles vary in shape, materials and amount of padding. When choosing a saddle, check that it’s wide enough to support your pelvis, and it’s comfortable.

Saddles can be gender-specific, meaning that they’re designed to suit the anatomy of men and women. But there are also great unisex saddles that bikers love. The idea is to find what’s best for you, with the right amount of cushion to prevent soreness.

Adjust saddle fore/aft positions

Next, you want to adjust the saddle fore/aft, which is how forward (fore) or backward (aft) the seat is in relation to the pedals.

The goal is to apply maximum force to the pedals with every stroke. 

To do this; 

  • Get on the bike and sit on the saddle, again with your riding shoes on. 
  • Put your pedals in position 3 0’clock and 9 0’clock, so your pedal cranks are horizontal to the ground. 
  • From this position, drop a plumb bob from the front of your knee cap down through the pedal
  • Look down to the plumb line.

If the line is dropping down by your toes or in front of the pedal axle, it means your seat is too forward.

If the line is dropping down behind the pedal or somewhere far back, it means your seat is too backward. 

The ideal position is when the plumb line bisects the pedal axle. And once you’ve got it set correctly, don’t make any more adjustments to it because that’s where it needs to be for the best biking experience.

Adjusting your reach

The next step is to adjust your reach, or how far forward you have to reach from the saddle to the handle bars.

Reach to the handlebars

A longer reach indicates that you are slightly more upright and relaxed, while a shorter reach puts you in a more aggressive position. 

The best combination for comfort, aerodynamics, and power is achieved when your body is positioned so that it is at a 45-degree angle to the horizontal and the angle between your arms and your back should be about 90 degrees.

Your reach is determined by the length and angle of the bike stem. The stem is what allows you to adjust the position of the handle bars so that you have the proper reach. 

You can adjust the reach by moving the bike stem a few centimeters up or down (2 to 4 cm), depending on how much space you have.

If your reach is too long, you should get a shorter stem. And if your reach is too short, then you need a longer stem.

Here’s a simple exercise to determine if you have the perfect reach for the correct bicycle riding position.

  • Sit on the saddle with your feet on the pedals, place your hands on top of the brake hoods.
  • From this position, locate the front hub in respect to the handle bar.
  • Your reach is perfect if the handle bar should conceal the front hub. This should place your back at a 45-degree angle.
  • You need a slightly shorter reach if the handlebar is in front of the hub. And if the handlebar is behind the hub, then you need a slightly longer stem.

You might need the assistance of a bike shop staff to find the right stem for you.

Here are a few more considerations when fitting a road bike

Handlebar width: as a general rule, your handlebars should be approximately as broad as your shoulders, measured from your armpits.

Some cyclists may prefer a narrower handlebar to gain an aerodynamic advantage, while others may prefer a little broader handlebar to open up the diaphragm and make breathing a bit easier.

Crank length: crank length adds to your riding power and efficiency, and you will need to adjust it depending on the length of your legs and your riding style.

The most common crank arm lengths are 165. 170, 172.5 and 175 mm, but it is possible to find cranks that are up to 180 mm.

The optimal crank length for you will depend on your height. Tall riders need longer crank length (170 mm and above), while shorter riders need shorter cranks. 

Here some points, if your legs are proportional to your height

HeightCrank length
5ft 5in and below 160 mm
5ft 6in – 5ft 8in  165 mm
5ft 9in – 5ft 10in170 – 172.5 mm
5ft 11in – 6ft175 mm
6ft 1in and above   177 mm (or more)

Saddle angle: Some cyclists prefer to give their saddle a slight upwards or downwards tilt. However, a perfectly level saddle is best for most riders.

We recommend that you start with your saddle level, get to know how it feels because you try changing the angle. 

Cleat position: adjusting your cleat properly is as important as fitting your bicycle, a properly-fit cleat will give you the most power to the pedal.

To adjust your cleat, find the ball of your foot, the center of the cleat should be directly under the center of the ball of your foot.  

Wrapping Up

This is no reason to be uncomfortable on your bike, and you won’t be with the right fit. 

A properly fitted bike is essential for all types of cycling. It’s vital to choose the correct frame size when buying a bicycle so that the bicycle can fit the rider, not the other way around.

You’ll enjoy riding a bike that is comfortable for you, and perfect for your height and riding style.

Poor fit on a bike can result in inefficient riding, aches and pains in your muscles, and general discomfort that will make it difficult for you to ride for as long or as far as you would like.

And finally, every bike rider combination is unique, so keep in mind that this is only a guide to help you get off to a good start.

With that in mind, use this as a starting point and then make any necessary adjustments from there.

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BikeCrunch offers the best riding tips and guides to help you get the most out of your cycling adventures. We offer in-depth bike and accessory reviews, unbiased buying guides, how-to guides, and much more. Mountain biking, road biking, commuting, touring, and recreational cycling are some of the topics we cover.