Is there a general rule on how wide handlebars should be relative to frame size? I own a 53cm road bike (I'm 5'10 ") with what I believe are very narrow handlebars. I would like to install the widest handlebars on the market, but given the frame size, I'm concerned the bike would look odd and perhaps be dangerous to other riders given that I would take more room on the road. I believe the widest handlebars made are 46 cm.

Handlebar width is generally dictated by shoulder width, not frame size. If you have broad shoulders, then you should get wider bars.

I think width depends on comfort. I am your same height and many years I used a 40 cm handlebar, but last year I got a new bike that had a 42 cms handlebar and I was surprised about comfort and safety, then got a new 44 cms handlebar for other road bike and noticed the error I was in, for many years, this is my width. I am a 38 cms shoulder and the rule to follow doesn't worked in me. I really feel good with this 44
, although it doesn't represent any danger to other riders, they dont see your handlebar. Even new handlebars are flat in the upper area and really helps in staying safe. Regards

I think width depends on comfort. I am your same height and many years I used a 40 cm handlebar, but last year I got a new bike that had a 42 cms handlebar and I was surprised about comfort and safety, then got a new 44 cms handlebar for other road bike and noticed the error I was in, for many years, this is my width. I am a 38 cms shoulder and the rule to follow doesn't worked in me. I really feel good with this 44
, although it doesn't represent any danger to other riders, they dont see your handlebar. Even new handlebars are flat in the upper area and really helps in staying safe. Regards

I am 6 ft, 200 lbs; 44 shoulders; 44cm handlebars are a really good fit for me. 46s look huge to me but if you find that more comfortable, go for it. By the way, are you sure your fit issue is handlebars. 53cm frame for 5'10" person seems kinda small and a too small frame would make one feel pinched a bit. I would think 56cm or even a bit larger would be more your size.

+2 53cm frame size is small for someone 5-10.

Thanks to all for the replies.. Yes, the bike is on the small size of my range but feels small only on the handlebar area. Thanks again..

Have a friend measure your shoulder width per one of the many road bike fit guides available on the web. This should give a base line to at least work from. I am your height and was just measured at the LBS to have a 45cm shoulder width. A wide but relatively short skeleton.

I got aa free full Serotta fitting as the LBS owners wife is in the process of learning how to do fitting and I was a volunteer victim;-) Serotta requires a fitter to do 10 fittings minimum to qualify for certification.

what is your discomfort exactly? "feels small" could be a lot of things. if we knew what kind of discomfort you are experiencing it would help us to make a more informed recommendation.

i will say though, that size seems too small, in general. I am 2 inches shorter and ride a frame 3cm bigger

Be careful when buying new handlebars - some manufacturers list the measurement as center-to-center, and some as outside-to-outside, which makes about a 2cm difference, which is the same as a full size increment. I believe Sheldon Brown and some other sites list which manufacturers use which standards, or some manufacturers may actually be helpfully enough to tell you this on their website. In addition, the tandem we bought 18 months ago came with FSA bars on the front that claim to be 42cm (it is printed on the bars), but when measuring they were definitely 41cm center-to-center or 43cm outside-to-outside, so there is a lot of variability in how different manufacturers measure bar size. Anyway, the 41cm version were too narrow for a tandem, where most people use slightly wider bars for more steering control at low-speeds, so I switched them for a pair that really WERE 44cm center-to-center, and now I'm happy.