It's ok if the rim has no eyelets, like a steel rim. Aluminum rims that have eyelets pressed in for standard 14 gauge nipples shouldn't be drilled out, as there is not enough aluminum material to support the load without spokes pulling through; thats what the eyelets are for. old tubular rims used to come with a pack of washers you added as you built the wheel. hubs are ok to drill out, if there is enough meat around the flange area. Its usually more cost effective to just buy a prebuilt wheel, but then you are stuck with the coaster hub.