Narrow vs normal vs wide: Which handlebar width should you buy?

Road bike handlebars are available in a few different widths, but which should you buy? To help you decide, we've tested a few different handlebar widths to test the difference, both in comfort and in speed.

Traditional bike fitting advice says that you should choose a bar that's the same width as your shoulders, but in many cases, people prefer bars that are wider or narrower than that. It all depends on your riding style, your unique physiology, and your priorities on the bike.

Read more: Do you really need a bike fit?

Speed and aerodynamics

A few years ago, most professional cyclists were riding 40 or 42cm bars. Now, pretty much everyone in the peloton has switched to narrower bars to reap the aerodynamic advantages. Narrower bars make your frontal area smaller, improving your aerodynamics.

Read more: Should you buy a flat bar or drop bar bike?

In fact, things were getting so extreme in the pro peloton that the UCI has put a limit on handlebar width, stipulating that riders must use bars that are at least 36cm wide.

To find out exactly how much difference it makes to aerodynamics and speed, Ollie Bridgewood tested 39cm, 41cm and 43cm bars in the wind tunnel.

Results

Ollie rode on each bar width at 45kph, which produced a CdA (coefficient of aerodynamic drag) for each of the bars. With that, we could model how each of the bar widths would affect a typical cyclist in a Gran Fondo like the Étape du Tour, and on a 10-mile time trial.

How much faster are narrow bars for a Gran Fondo?

We used the 2022 Étape du Tour as our 'typical' Gran Fondo. It was a 169.77km course with 4,923m of climbing. We assumed an average of 230W, which is typical of a keen amateur cyclist. Here's how long it would take to complete the course on each of the bar widths:

• 39cm: 6:17:34
• 41cm: 6:18:29
• 49cm: 6:19:27

That equates to about a minute slower with each additional 2cm of bar width. Over such a long course, that might seem like not very much. The reason the difference is so small is because the aerodynamic advantage will only come into play on descents and on the flat, when riding quickly. On a hilly course like the Etape du Tour, most of the day is spent climbing at low speeds, and the aerodynamic advantage will only come into play on the descents.

How much faster are narrow bars for a 10-mile time trial?

For this model, we assumed the rider would average 260W, which is pretty typical for a fit amateur rider. Here's how much time it would take with each of the three bar widths:

• 39cm: 24:17
• 41cm: 24:21
• 43cm: 24:27

That's only about five seconds between each of the bar widths. Again, that might not seem like a lot, but over a short effort of around 24 minutes, 10 seconds can make a big difference, especially in the results table of your local time trial. Often, gaps of far less than 10 seconds are the difference between winning and losing in a time trial.

Equally, in a race, a breakaway rider would be glad to get an extra 10 seconds on the rest of the field. Again, that could be the difference between getting caught on the line and claiming victory.

Comfort and handling

For many of us, though, the marginal speed advantage of narrower bars is irrelevant. Far more important is the comfort and control difference between each bar width.

When it comes to comfort, it is of course a personal matter, with the 'correct' width for each of us depending on the width of our shoulders.

Even so, Alex Paton set out to investigate what it's like using bars that are wider and narrower than that typical 'shoulder width' measurement. How does it affect comfort and control?

To find out, Alex rode three sets of bars back to back on a test loop. The three widths he tested were 36cm, 40cm and 44cm. Here's what he found.

For comfort, match your bar width to your shoulder width

The 40cm bar is what Alex normally rides, so it's no surprise that he found it more comfortable than the narrower and wider option, but he attributes that comfort to the fact that the 40cm bar allows him to line up his hands and shoulders.

For stability, control and sprint power, go wider

The wider 46cm bar gives more stability and control, as the extra centimetres give you more leverage over the steering, and a more solid, triangular base. If you want a bit more confidence on the bike, or if you are thinking of taking your bike off road, then going a little wider could help.

A wider bar gives more leverage when riding out of the saddle too. That's the reason that Andrew Feather, national hill climb champion, opts for wide bars, as does Mark Cavendish, who told us a few years ago that wide bars help him sprint out of the saddle and manoeuvre the bike.

What size handlebar do you use? Let us know in the comments.

Explore more buying advice over on the GCN website, linked here.