Just curious. I see bars listed with widths such as 39cm, 41cm, etc. On my bikes (not counting my wife's randonneur style) I get different widths depending on where I measure it. For example, on my UO8 (the only bike in the house with original bar) it measures 36cm above the brake levers, 37cm at the most forward part of the bend in front, 39cm and the bar ends. The bar on the tandem is similar but wider, and on the Raleigh it is proportioned a bit differently. I think I like the narrower bars though the wider bar would seem better for control on the tandem. Mostly it doesn't matter much.

The most obvious measurement point would seem to be the bar ends. Is that was is normally meant by a bar width spec?

I have always measured it at where the brakes are. But when I was looking for wider bars the owner of my local bike shop measured them at the bar ends. He said that was customary.

I believe it is, Jim. That's how I measure them. It's just important to note any significant differences in the width throughout the bend, such as with a randonneur bar. I measure center-to-center at the bar end openings.

Road bars are customarily measured at the end of the bar. But not all manufacturers measure c-c. Most notably TTT and Deda (and probably others) measure outside to outside, so their bars measure 23.8mm (the diameter of the bar) narrower than, say, a Nitto of the same nominal width.

SP
Bend, OR

"The bike industry loves standards. That's why there are so many competing ones."

Measurements mean a general size. Bars are so different.
If you have one that you like, find the size you like and stick with it.

I've seen drop bars "sized" in a couple of different ways.
I've seen people buy their "size" in drop bars and then ride the hoods 100% of the time.
Then there are ergos, randos, and all manner of dogs and cats.

I only ride one kind of bar, and I know my size, so I've no need to measure.
However, years of trial and mostly error on a potpourri of sizes and a plethora of bends got me to that resolution.

That being said, I have one bike to smack into submission, to replace a 100mm black Nitto / B115-420 with a Cinelli of equal size and color.

I measure with a metric tape.