The handlebar on a road bike is possibly one of the most commonly overlooked aspects of bike fit – both in terms of selection and adjustment. For the most part, the bars are accepted as is and taken for granted by the rider, without further thought. However, they are worth more attention as the choice of handlebar can be a very important factor affecting hand position and comfort on the bicycle. As a bike fitter, I have found that a change in handlebar can be one of the most significant adjustments made during a bike fit session, much to the surprise of the cyclist.
If a cyclist does go down the path of changing their own handlebar, it is usually simply to be “more aero” without giving consideration to other factors – of which there are many.
But first, what role does a handlebar play on a bike?
The Purpose and Function of a Handlebar
The handlebar provides the principal means for a cyclist to control the bike. It also provides a means for the bike to control the position of the cyclist. Hence there is a 2-way interaction and feedback loop at work.
To control the bike
The 3 primary controls are:
- Steering
- Braking
- Gear selection
Only the bar is needed for steering, but the controls (shifters/ brakes) are also located on the handlebars, although once upon a time the shifters were on the downtube on a road bike.
Depending on your hand position, you may only have ready control of the steering and need to move your hands to get to the brake levers or change gears. And depending on finger length and lever reach adjustment, you may only be able to access the brakes from the “hoods” only and not in the “drops” as well. Ideally, you can access both gears and brakes from both the hoods and drops.
To control the body
The handlebars should never be considered the primary place for bearing weight on a road bike, but you will put some weight into the bars, and the position of your hands as well as elbow and hip flexion will change your trunk position. Hand position, trunk position, and weighting all feed back into your body and how it both feels and functions on the bike. Having the handlebars and therefore your hands, outside a suitable “fit window” will add too much compression or extension to your spine and postural control muscles, causing fatigue and tension. This in turn detracts from your steering control, and numb fingers or hands are not ideal operators of brake and shift levers. As a result, bike control becomes compromised.
To understand both the issues and opportunities with handlebar selection, we’ll first look at the hand positions a cyclist can use on a road handlebar, and then the design features of the handlebar itself.
Hand Positions
There are 3 primary hand positions on a road bike handlebar:
- Tops
- Hoods
- Drops
The tops is a more relaxed upright position but without immediate access to brakes or gears.
The hoods is (or should be) the default position for the majority of recreational cyclists most of the time. Here you have all 3 controls available.
Riding short on the hoods is to have your hands closer toward you, backed off from the hoods.
The drops is a performance-orientated position with benefits for power production, aerodynamics, steering control when descending and cornering, and braking power. This should be an available position (as in, you can ride there comfortably), but it also takes more practice, core strength, and mobility. There are variations in the drop position, depending on the shape of the bar.
Handlebar Design Terminology
Before getting into problems and solutions, it is helpful to have an understanding of the terminology used to describe handlebars. This will give you insight into the surprising number of variables that make up a handlebar and will help explain why they can feel so different.
The main design factors are:
- Width
- Reach
- Drop
- Drop shape
- Top profile
- Flare and Sweep
Width: how wide the bars are. This usually doubles as the size of the bar. Being a bicycle product, there is no standard way to describe this measurement, and as a result, one brand’s 42cm bar is another brand’s 40cm bar. Hence the size printed on a bar may not equate to how you may measure it.
There are 3 main methods used to describe handlebar width:
- Center to center across the top. This is the most common method for US bars and the method I use when describing bars.
- Outside to outside across the top. This is more common with Euro brands like Deda.
- Center to center at the bottom end of the drops. Yes, someone (FSA) had to do it differently. Note: some bars are the same width on the top and across the bottom, and others are not, due to flare or out sweep. FSA bars are wider at the bottom (where they measure) than at the top. Enve conveniently and impressively communicates the width options both C – C on top and at the bottom of the drops.
Bar width is expressed in either mm or more commonly, cm.
Bars cover a 10cm width range, from 36cm to 46cm. Not all brands and models cater to all sizes. The 3 most common sizes are 40, 42, and 44cm. One of these 3 sizes will be suitable for most, but certainly not all riders. If you are a human outlier, you may prefer a narrower or wider bar to the standard offerings. Many cycling humans of smaller stature and shoulder width prefer a 38cm bar.
Reach: the distance along the bar running away from the rider to the controls. See the diagram for a better visual explanation of this! Usually expressed in mm. Reach is a 
measurement used in several ways for bikes and bike fitting. Note this is not the same as frame reach, nor is it HX, which is a handlebar reach measurement from the bottom bracket. Modern bars commonly have a reach of 70 – 80mm. Bars in the past had a reach of 90 – 100mm, as may some specialty performance bars.
Drop: is the vertical distance from the top–center of the bars to the bottom of the bars. A deeper drop can accommodate a larger hand. A deep drop for a small hand can make the drops feel a long way down and away. A bar with a short drop might not offer enough space for a large hand. A handlebar drop should scale to suit the size of the cyclist’s hands.
Drop Shape: the curvature of the drops, viewed from the side. There is no easy way to describe this, but different bars can feel very different due to this variable. If the hands feel uncomfortable squished when riding deep in the drops in order to reach the brake levers, the shape is probably wrong. There is also variation in how far back the lower portion extends to the rider. I have seen bars recently with not enough length to support a hand anywhere other than deep in the curve.
Top Profile: the cross-section shape of the top of the bars. There are 3 common top profiles.
- Round: the most common profile section, and the cheapest to manufacture.
- Ergo: an ovalized cross section intended to increase hand comfort by being a better shape to hold onto when riding on the tops.
- Aero: a flattened cross-section to optimize airflow over the bar. Also more comfortable to rest the forearms if riding in the now UCI-disapproved “road aero” position, with your hands out in space off the front.
Flare and Outsweep: design and engineering variations on a theme that result in the drops being angled out such that the bar is wider at the bottom than the top. Many 
gravel drop handlebars feature noticeable flaring, and some take this to the extreme. Flare results in a wider hand width when in the drops, which is promoted as offering more steering control and stability. What a flared bar actually does is unlock the elbows and shoulders and improves mobility in these joints for more responsive steering and shock absorption on rough terrain. More akin to a mountain bike handlebar. A non-flared bar tends to lock the shoulders and scapula into place – which is more stable on smoother pavement.
Backsweep: is any amount of bend back toward the user, along the top of the bars. This is uncommon to find, but some progressively designed bars feature a backsweep, which is reportedly more comfortable for the hands and wrists when riding on the tops. The most notable example of this is the Coefficient bar.
Problems and Opportunities
The wrong handlebar for the cyclist can be the underlying cause of a range of discomforts, including tension in the upper shoulders and neck, as well as elbow pain, wrist aches, and hand numbness.
In addition, the handlebar is a variable that can be used to change the position of the cyclist if other variables are either fixed or maxed out.
Width is the most common handlebar variable to explore, and the one with the most impact.
A trend in the pro peloton is to run a narrow bar for a more aero presentation, as well as less protrusion into limited peloton space. Rule #1 Don’t imitate the pros!
A starting point standard rule for how to choose a road bike handlebar width is to match the width of the cyclist’s shoulders between acromion joints. As with any standard rule, this will hold true for some and not others. From the front, most cyclists prefer their arms (when hands are on the hoods) to be in line with their shoulders. Too wide strains the posterior shoulder muscles. Too narrow inhibits breathing. A key driver of handlebar width should be ease of ventilation. Handlebars too narrow or wide will increase tension in the rib cage muscles, and therefore diminish ease of breathing and breath capacity.
Symptoms of a handlebar too wide:
- Wrists turned in to try and narrow the gap between the arms.
- Hand pressure biased to the ulnar pad (heel of hand behind the little finger, due to the wrist being turned inward.
- Tension between the shoulder blades and/or up into the back of the neck.
- When riding a bike feels like wrestling a bear or carrying a box too big.
Symptoms of a handlebar too narrow:
- An elbows-out riding position to try and open the shoulders and increase breathing capacity.
- A sensation of falling off the outside of the handlebars and having to grip more tightly to hold on.
- Reduced/compromised breathing volume under higher workload.
- Shoulders hunching up and in (elevating and protracting).
Signs of an optimal handlebar width:
- Ability to easily complete full inhales and exhales.
- Wrists are in line with hands when on the hoods.
- Elbows can relax and flex down, rather than out.
- Shoulders can relax and there is no undue tension in the shoulder blades or neck.
Most cyclists can happily ride a couple of different bar widths, but often one is likely to feel more favorable than the other. This is why it’s helpful when bike fitters use tools to allow cyclists to test out different handlebar widths in order to find the rider’s preference.
Reach. Choosing a road handlebar with a different reach is an option to address the overall reach to the handlebars. For example, a smaller rider on a small frame with an already short stem is still not comfortable stretching out to the hoods. If the bar reach is 80mm, changing to a bar with a 70mm reach is much the same as going down another stem size, and can be the change that makes a difference.
The same can apply to a rider who likes to stand to climb. If there is a lack of clearance between the knees and the bars, a longer stem can give more leg clearance to the top of the bars, and a shorter reach bar can bring the hoods back toward the rider so they are not too stretched out when seated.
Drop Depth and Profile. Want to ride in the drops but the shape is not agreeing with your hands? Different shapes for different hands! You might need to wrap your hands around a few handlebars to find a shape you like. Some bars are not long enough at the end of the drops, some are too pinched in the bend, some are too cramped, and some are too roomy. Sometimes it is not the profile as such, but the rotation of the bars in the stem. I like to set the rotation of the bars for hand comfort in the drops before setting the position of the hoods, for hand comfort in that position, but sometimes a whole different shape is needed.
Top Profile. Some cyclists spend a lot of time with their hands on the tops rather than the hoods. An ergo profiled top is often the most comfortable. If you want to lay out on the bike with your forearms on the tops, a flattened aero-style handlebar is going to be more suitable and comfortable for this than a round or ergo profile. An aero profile bar is generally not that comfortable for a hand position on the tops. These are designed for speed, not sitting up and cruising around. If you are a tops rider and are having wrist or elbow issues, you may want to invest in a Coefficient handlebar which will put both joints in a more relaxed natural position.
Flare. If you have large thighs, and your arms are in the way of your legs when riding in the drops, you might prefer a bar with a bit of flare, such that the drops are wider than the tops. This will place your hands further apart when in the drops, providing more clearance for your thighs.
The Wrap
As you can see, there are a lot of variables regarding how to choose a road bike handlebar, and while some of these may be subtle, others can have a profound impact on the cyclist’s comfort, and control of the 
bicycle. Positioning of both the bar and the hoods, as well as lever reach adjustment are all additional and important factors to optimize the fit and function of the bike. More on those later!
John is an elite level bike fitter who works with non-elite cyclists – although a few have won races! Many don’t race at all, but ride for fun, fitness, or to compete against themselves. John has worked with 18-80 year olds (and younger and older), novices, age groupers, masters racers and all levels of weekend warrior. These include road riders, mountain bikers, triathletes, tandem riders, tourers, commuters, bike packers and gravel riders and racers. All share a love of cycling and just wanted to ride more comfortably, and in many cases faster. John is the owner of Fit Kit Systems, and provides bike fitting services through BikeFitr (bikefitr.com)