Handlebar width is a personal choice, and it can also be tied to visual style of the motorcycle. Wider bars tend to be associated with 'cruisers', whereas drag bars, T-Bars and rabbit ear handlebars give a more aggressive riding posture, and lend themselves well to a hard ridden, fast motorcycle. Note that wider bars can easily be cut narrower with a hacksaw or grinder with a cut-off wheel. However, you have to make sure that you have enough straight tubing in the hand grip area for your throttle and levers. Also, if the bars are dimpled for Harley style hand controls, you cannot cut them shorter as the handlebar grips
and hand controls will mount at the dimpled section and be too far outbound.