I've heard it said there's a desired relationship between a rider's shoulder width and the handlebars they're comfortable using on a road bike.

Haven't yet been able to find a succinct description of what that relationship should be.

I'm at a point where I think my '23 Tarmac SL-7's as-received handlebar is too narrow @ 34cm for my 40cm wide shoulders (as measured to the outsides of my upper arms at the shoulder joint). Exploring what's out there now, need some idea of what to look for in a proper width.

To narrow and you can’t breathe right.

Pros have been going to narrower bars over the last few years, to the point where, for the first time, the UCI has had to mandate a minimum width (no bars narrower than 35 cm outside to outside are allowed; they also established a limit to how far inward the brake levers can be canted, to keep riders from achieving even narrower positions). If they can remain competitive during 5-hour stages through the Alps, I would guess they're not having much trouble breathing.

Another formerly unquestioned standard is being supplanted: after many decades when almost all pro riders used crank arms that were 170 mm or longer, the two most recent Tour de France winners have been using shorter ones: Pogacar is on 165-mm cranks, and Vingegaard is riding, or at least testing, 150 mm.

Traditionally bar width supposed to be roughly same as shoulder width.

As above the pros are moving towards much narrower because it’s more aerodynamic/faster, but may be less comfortable.

I say go by what feels most comfy.

These guys are probably 135 wet

I think the 2 bony protrusions front of shoulder. Roughly.

Comfortable enough to last 5 and 6 hours a day, day after day, at pro speeds.

Also, the point I was responding to was specifically about restricted breathing, which obviously isn't happening.

I have noticed that the more unstable the ground the wider I like my bars. It's not very much and that surprises me. I ride mostly torn up asphalt, RAVEL, with a few nice stretches of smooth and flat. The difference between my wide and narrow bars is not more then 3cm. Gone are the days I could just hop on a bike and take off. Now days I need to adjust the bikes set up down to the millimeter for a comfortable ride.

If your an older rider its a matter of finding whats comfortable for you. Those young professionals can ride just about anything and leave us geezers enjoying their breeze as they sweep by...

Many track sprinters weigh upwards of 180 to 190 pounds, very little of it fat, and almost all of them have been using very narrow bars for the last few years. If those bars restricted their breathing significantly when sprinting at eyeballs-out effort levels, they wouldn't use them.

Here's a Bike Forums thread from 2018 where track racers swap tips on how to adapt to narrower handlebars, including interesting stuff that's news to me. For example, post 13:

"Not sure if this has been mentioned, but when you go to a narrower bar, this pushes your torso up...so you need a longer TT and/or stem to compensate. I ride a 58cm road bike 61cm track bike for this reason. The bars are narrower on the latter. Just adding more stem could affect handling. Sometimes more TT is what’s best."

Just for fun, for anyone who hasn't watched track sprinting, here's a national championships highlights video from last year. Note the narrow bars for both the women's and men's events.

You Tube

with typical bar widths it's kinda difficult to go too narrow. There usually isn't a real downside in terms of fit. That breathing thing was a bit of a myth back in the day but as shown above, said statement doesn't really hold water anymore.

Too wide is the danger zone. That'll wreck your wrists, elbows and shoulders. Gravel bars with the flared drops can allow for going a bit wider since the elbow turns a bit to the outside. But the difference isn't huge.

As a general rule I'd say don't pick bars that are wider (outside to outside) than the bony protrusions at the upper arm / shoulder junction. For me that's 44cm but for most people that's 40cm or less. Of course using bars which are as wide as shoulder width can feel more comfortable. Or using a narrower bar can feel more comfortable. It depends. My road bike has 44cm bars and that's my best fitting road bar bike. My touring bike has 42cm bars and it's not as nice.

I hope that new UCI rule doesn't apply to women, because a lot of females need bars in the 34cm region. Funnily enough bars that narrow are difficult to come by.

I don't really put much faith in any adage or advice about what width bar someone must have. I think it's just what you prefer. Though there are pro's and con's for any. And that also includes specific issues you might have with any bar width while riding.

The most common advice from BITD was the distance between the acromion process of your shoulders. And that is quite a bit less than the outside measurement of what you think are your shoulders.


https://en.wikipedia.org/wiki/Acromion

My 56cm Tarmac came with 42cm wide drops. I changed them to 38cm wide drops of the same model bar and the bike seemed to handle way more naturally through fast downhill twisty turns. I was able to better avoid road hazards seen at the last minute. And I was more comfortable on longer rides where older wider bars gave my arms a wider stance and seemed to brace me too much from the side to side forces that we have as we pedal along.

I'm not sure why some have trouble breathing. Perhaps they only know how to breath by moving their chest. I've never had any issue breathing with my arms in any position. Even if I am to put both hands right next to the stem.

Those red spots on Iride01's picture are the classic points. BITD we held the bare bars, no plugs, with the the ends fitted to those protuberances. It's a very exact and reproducible fit. And the resulting bar worked really well in mass start races. Physically, chronic injury-wise and for power output, about as good as it gets. Plenty wide enough for any road handling. Narrow enough to fit into gaps between riders the rest of you will fit in.

Over the years two things changed for me, both altering that "standard". 1) - my shoulders got narrower. Nothing else changed so why would I narrow up the bars? (Multiple broken collarbones not set with pins will do that.) And I have less strength and confidence in my advancing age than I had when I was in my 20s and 30s. Slightly wider bars = more security on iffy surfaces, And wedging myself between riders going 25+ mph is something I haven't done in many decades.

Touching the bar ends to the boney protrusions in the shoulder works, with two exceptions:

Some brands of bars are measured center to center, others are outside to outside. So a 42 of the first type is going to be more like a 44 of the second.


Some bars flare at the drops, so the width at the end plugs might be 42, but only 40 at the hoods. If I was using such bars, I would go up a size so the hoods are at my desired width. Enves are like that.

Road Bar width - I was always on the narrower side of bar width - given my wide shoulder span... for 4+ decades
Quite narrow for track & Crit, and a bit wider for road...
comparing bars from the 20th century to the 21 isn;t very productive... Shapes/drops were very different, brake positioning was different, using DT shifters determiined your position on the bars.
Being forward and having to quickly transition to faster rpms on track, made position very important...
vision while in a road peloton also brought requirements.
No longer racing these past dozen years, has had me change a lot on my position/posture.
Still more aero than most, but also focused on relaxed. I find that forearms parallel to bartops is as aero as being in the drops on these modern bars - and much easier to extend if I need to look over someone's shoulder... I'm also never in the drops these days, except to have a change of hand/arm/shoulder pressure.
Really wide bars (44 +) don;t work for me. I align my hands well within my shoulder span. Wide bars cause A-framing which means locking elbows and shocks into the shoulders and neck.
not good...
I like my position with elbows bent, elbows in-line with my shoulders and wrists/hands, and slightly inward of the shoulders...
so currently 40cm outside on performance road bike - daily ride has 42 c to c.
I tried the inward tilted shifters - that's one trick this old dog wasn't liking...
Flared Angled bars - anything like the ones shipped on gravel bikes - serious No-Go !
Ride On
Yuri

Thanks all!

I'm going with a 42cm, same width as what came in the box last September. Different style though, looking to alter cockpit a little by raising bars w/o adding spacers, so I have one of Specialized's Hover Expert 15mm rise alloy bars incoming next week.

42cm is comfortable enough for me out riding the roads. I don't race, rarely ride the drops. Arthritis in left thumb makes any prolonged hand position uncomfortable so I'm glad the FDR's brifter's on the left, that doesn't get much activity.

The "wider bar opens up your breathing" myth was a sort of late '80s fad, along with longer cranks and lower cadences A lot of medium-sized riders were going to 42 cm, and the big guys were using 44s. Triathlon killed that one. I found that going from 40 to 44 gave me better leverage when climbing out of the saddle. I replaced the 44 on my Madone with a 42 and I'm not looking back. If anybody has a nice 42 cm Cinelli Campione del Mondo (mod 66 or 63), with the older 26.4 mm clamping sleeve, let me know.

it is nice to experiment. i have drop bar roadies from 33 - 42cm at the hoods
all handlebars are aluminum.
seeking a narrow frontal comfortably on 60+cm frames

I started on 38cm bars in early 80's, old habits die hard
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and long-ish stems.


33cm above, 35cm below

I read recently a suggestion that narrower bars may relieve hand discomfort. Or conversely, too wide bars may contribute to hand discomfort. I feel compelled to pick up some narrow bars at the co op and give them a go on my rando bike.

Maybe it's the last tweak before a perfect fit lol.