A wider rim gives the tyre a squarer profile. It makes it a bit slower pedalling but gives better traction for less lean in corners. I've run 2.1's on the mavic 321d (now called 729) and really liked the result.aggro said:What would be the minimum tire size you would run, 2.3? How does a Dh rim this size ride overall? Any info on wide rims would be appreciated!