I wonder why new road bikes have such wide handlebars? Old ones used to have much narrower, anybody knows what's the reason behind it?

Size matters.

My Trek Madone came with 42 cm bars. When I wanted the FSA Plasma bars, Wiggle had a great deal on 40 cm so I got those and never noticed any difference.

42 is ok but I've seen like 46 that's very wide especially in traffic, no way you can ride between cars I'd never get out of my city lol

Measure the width of your shoulders, use bars of the same width.

Most bikes that come stock with 46 are probably gravel bikes with flared bars that are designed for stability off road

I'm much more comfortable on wide bars. I use 44 (at hoods) but 46 would work even better.

It's just shifting trends. They will probably start getting narrower soon on complete builds - a lot of professionals are already riding much narrower than a few years ago, and a few aftermarket models have a sweep that puts the hoods inboard from the nominal width at the bar ends.

+1. It seems that, after a long period of complaining from wide-shouldered folk, manufacturers finally started making wider bars, prompting more of the general public to experiment with them. There's also that hard-to-kill myth that narrow bars make it harder to breathe.

But it seems that people are now realizing that bars far wider than their shoulders aren't conveying huge benefits, so the pendulum is swinging back.

Road bars have not become wider in general, right? I see practically every bike with 40, 42, or 44, depending on size. 46s are still harder to find. So I don't see anything swinging back, since the only change was that 44 is a much more common size now. Now when it comes to mountain biking, wide bars are here to stay. I was on 680mm and always found those slightly narrow. So years ago, I moved to 710mm and am now on 740...huge difference in handling, and comfort on long rides. 760 would be my max (and have long arms...6'3 span) but 780 is common now. Stems have become much shorter. I think the big change is in mountain biking where you have to throw around the bike a lot.

That you didn't include any sizes under 40cm bolsters our point.

You may not see as many 46cm bars in the wild, but they aren't hard to get.

That's funny. I now vaguely recall 38 cm bars.

Bar width and stem length are approximate sizes for the frame size on stock bikes. When I bought my Cervelo (54), it came with a 90mm stem and a 42cm bar. I swapped it out for a 110mm stem and 38cm (c to c) bar. First things to go were the bar, stem, and saddle.

I used to have 38cm on my old bike then I had accident and it broke, I had very hard time finding this size, only one I could find was made in china. Now I got "new" bike and it's got 40cm, bit wider but ok for me, I would not go for anything wider than this though it's not good for me to ride with my arms spread out like a superman lol

When I was researching an '80s Italian bike, I saw in some Cinelli catalogues of that era that the drop bars were only available in 38, 40, and 42 cm.

I'm currently in the process of replacing my stock 44 cm drop bars with 40 cm aero drop bars. One thing I've noticed is that both bars (Cannondale originals and Bontranger replacements) and are clearly measured c/c from the hoods. Both are about 2 cm wider at the bar ends. I've seen a few people suggest that handlebars are usually measured at the drops, but that doesn't seem to be the case with these two modern bars.

i use 44cm bars, but i have really wide shoulders and should really be using 46cm bars. for me, the problem with 46's is that most 46cm bars usually really bad bends in the drops and a noticeably longer reach than 44cm bars. me personally, i'd rather go with a 20mm longer stem with the 44's over the shorter stem and longer 100mm reach with the 46's, plus you can get 44's with a nice compact drop if you want...

The whole drop handlebar size thing mystifies me. The measure your shoulders method is merely a start, as I know a lot of riders who use a size down from what the measurement would indicate, and they like and prefer them to the slightly larger ones that the measurement says they "should be using". I'm included in that. I use 42s when my measurement indicates 44 should be the size. I've used both long enough to know I prefer the narrower ones. I realize complete bike sellers need to put something on their bikes, but the sizing guide most seem to use seems a size off to me in general. I don't think a lot of people out there need 44s. Some shops will swap out bars on a new bike for free, some won't. But if buy a new bike and something just doesn't seem right with the bar width, buy a cheap one in a different size and try it out. You may prefer the other size (which is probably going to be smaller).

I thought I was a 42cm guy for years, since that's what my first road bike had on it, and it seemed to feel fine. So I followed suit when building up other bikes. Only later did I measure my shoulders, try bars around the 38-40cm range, and realize how much better it felt. Wish I'd thought of that before buying all those other bars!

I'm going to resurrect this old thread rather than starting a new one.

Will I ever get used to 44cm bars or do I just naturally not prefer them? I've always used 42cm until I made a measurement and found that I "should" be using 44cm. After an install and some riding, I just don't like the feel of how wide they are. Am I just not used to them yet and need to give it some time? Another kicker is the other bike still has 42cm bars and I've been riding it a lot more lately and I never planned on changing those..

you can probabaly get used to them, but bars are so cheap run what you like. I use 38cm on the road bike for aero purposes, 42cm dirt drops that flair to 50cm+ on the gravel bike, and 46cm bars of the cross bike. Make sure you account for the extra width in terms of reach. I like to measure at an angle from the tip of the saddle to the hoods to check effective reach between different setups

There's no "ideal" bar width, any more than there is an "ideal" shoe size. If you're comfortable with 42s, then use them, regardless of what some measurement says you "should" use. You can probably get used to anything, but why should you?

I bought a cheap bar to try some new specs, but I've always wanted the Easton Aero bar so I guess it's a good thing I didn't go that route first.

People care more about what they think will be comfortable than what will be fast.

If you're concerned about speed, then because 38s are significantly faster.