Just wondering what flat bar length you guys are riding with on your hybrids. I recently bought a used trek 7.3 fx and its 23in feels a little short but maybe i just need to get used to it.

Are you referring to the width of the bar? If so, then I think the best width of the bar is the width of the shoulders. Hands directly in front.

Yes, the width. Its pretty much right on with my shoulders so i guess im good. Thanks for the reply

I personally prefer wider than the shoulder guide. If it feels OK now though I wouldn't change it.
My centre to centre (sockets) is 400mm. My bars are 680mm

Bar width depends on what type of bar: risers are the widest, followed by flat, and drop bars are the narrowest. Only drop bars are directly shoulder width + 2 cms. The rest are much wider, especially if you run a modern setup with shorter stem and riser bars.

For example, my shoulder width is about 32cms (less than 13") but my riser is 23.5" and flat bar is 23".

Modern setups are already using 700mm to 800mm wide bars. If your shoulders are really 23" wide, you should really look at a wider setup

The "best" width is the one you prefer -- simple as that. If you want something wider than 23" (around 580 mm or so), go for it. My preferred width (flat bar) is 620 mm (both mtb and flat-bar road bike). Some prefer wider, some narrower. Experiment (bars are relatively cheap)!

Good advice. foes feel a little narrow but ill try them out for a while

Yes, I agree. I do believe however that we get used to a particular length. My current most used bike is a specialized crosstrail, it's bars a little wider than my cannondale. When I first got it, it felt awkward, but now I'm used to it and it feels fine. If my cannondale had wider bars than my specialized I suspect that too would have felt awkward. I think Mr. Einstein said something about things being relative.