In the ‘Old Coot’ column of the newest Dirt Rag Magazine, Bill Boles talks about how he found that the farther his arms are apart on the handlebars, the easier it is to ride because it opens up his chest more and allows him to breath better.

The Blue Collar part comes in with his idea for getting the most out of the handlebars he already has. Instead of dropping the cash to but a wider set, he just moved his grips and controls further out and cut off the excess grip material with a razor knife.

I would suggest, as he did, that you start with a half inch then go for a ride to see how you like it before going for more.