Presta to Schrader

My kh29 uses presta valves, which I find rather annoying, but also harder to buy tubes for 29+ than for the Schrader version. How practical is it to drill out a rim to use Schrader valved tubes?

Depending on what tools you have it may be easier to file the hole a little larger with a round file. In any case you will want to file or sand the rough edges if you do drill it.

Unicycle rims are wide enough that drilling won’t effect the strength of the rim. We used to drill rims on touring bikes for customers who wanted the flexibility of buying replacement tubes at hardware stores along a tour.

On bikes as rims got narrower the valve had to get smaller so the rims wouldn’t be weakened at the valve hole. I doubt we would have ever seen Presta valves on bikes if not for the skinny light rims made from soft aluminum.