Originally Posted by rpenmanparker

You can use that rim for 23 mm tires on up to at least 28 mm, probably 32 mm, but don't take my word for it on the 32s. As compared to a 19 mm rim (the old standard), all tires on your rims will measure larger than their nominal size. The 23 mm tires will be more like 25 mm tires on a 19 mm rim. So you have to be sure that you have enough clearance on your frame for the slightly larger size. That increase in size also translates to the ability to inflate the tires to a lower pressure without risk of pinch flatting your tubes. That will give you more comfort than with a true 23 mm tire inflated to a higher pressure. All around a good thing.