carleton

A few years ago, the road standard was 44cm wide...even for smaller riders. This helped with climbing as well as what I call "roadie sprinting" where they wave the bike from side to side. Actually, it encourages that type of sprinting.

If you did that kind of sprinting on the track, you'd make a mess as everything happens in tight quarters. So, with that being the case, narrow bars 38cm or less make it easy to ride in close proximity to other racers without fear of having your handlebars bumped. The first contact is usually the shoulder or elbow.

There are also some (minor) aero benefits. I don't think anyone has ever put on narrow bars and shaved off crazy amounts off of their times. But, less body in the wind is less. So, there are benefits.

Standing starts can feel awkward on super narrow bars (33cm and the like). But, you get used to it after a few sessions.

40cm used to be the track standard back in like 2010 and earlier. Now it's 37cm (or less) for big guys and lower for ladies, smaller riders, and juniors.

Everybody thinks it's weird and assume they won't like it...then they try it and don't go back. I can't recall the last time I've seen 44cm bars on the track. Even roadies and Madison riders will use narrow junior road bars on the track.