My bike fitter recommended I get 44cm on my bikes. Aside from aerodynamics which I'm not too concerned about, Is there any reason not to go for 46cm for more comfort?

On my loaded touting bike, with 4 panniers I went wider.. leverage for that mass..
Nitto 48.. On Bike tours I spend most time on the tops not brake hoods YMMV

but the classic width test, road bike coaching, matches your shoulder's width,
so it's up to you. do as you see fit.







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How much have you been riding?

How tall/"Big" are you?

I think mountain bikers like wide bars, but I'm not at all sure they're called for on road bikes.

Drop bars and flat MTB bars position your arm and shoulder joint differently. For elbows down (drop bar position), your really don't want to go much wider than your shoulder width because you are pushing the shoulder joint closer to its limits. The classic bar width formula gives you a bar that is good for your shoulders and wide enough to not interfere with breathing, though going narrower is rarely a problem.

If I had 44cm shoulders, I would not get 46cm drop bars to avoid shoulder damage/discomfort.

You aren't going to benefit from the tiny difference in leverage.

This is a notable problem. Also OP pay attention to flare/sweep angle. "Width" is usually defined by the position where the brifters are.

For example I have a 46CM Thomson bar (no flare/sweep)...that is as wide on the hooks as my flared Salsa Cowbell. Both are comfy, then again I have broad shoulders.

Center to center is the normal way to measure bars, so if your fitter recommended 42s, he was talking about 42 center to center. A minority of bar companies measure outside to outside, and if they do you would seek a 45cm size to equal 42cm center to center.

So you're on bars 2cm narrower than recommended.

Thank You. That's the kind of informed response I needed to hear.

Wider isn't more comfortable. You want your arms to be parallel to the bike centerline, hence bars of shoulder width. You need very little leverage to operate a road bike or road motorcycle. My bars on our tandem are the same width as the bars on my road bike.

I ride 38cm on the road and 44cm for cross, 42cm for gravel. I was fitted for 42cm bars the last time I was fit, but discussed the tradeoffs with the fitter.

I'd rather the bars be narrower than wider. But I've only ridden road. Don't know what might be different if it was on a cross bike on fairly rough conditions.

If I were to size based on shoulder width of 17.25 then I'd be on 44 cm bars. But I prefer my 38 cm bars on my Raleigh though I've been riding 42 cm bars on my Paramount the most lately. Not a big difference but I can't see wanting wider. I don't like my hand being that far out when one handed on the brake/shifter and trying to get a drink.

If you haven't already, be sure you discuss why with the fitter. They might know something about you that we don't.