Yeah, seriously. It's like WW has a forum full of non-weight weenies all of a sudden. WTF are you all doing here if you aren't interested in tuning and getting the most out of your components as the very basis of the forum? The CycleChat and Pro talk and all the other stuff is just icing on the cake.
I don't know how I missed this thread the first time around, but I was thinking about "modifying rims" myself... and so here it is.
I'm surprised at the negative responses right off the bat... none by anyone who had actually tried it. And I'm an engineer, and I'll tell you that IMO it isn't a stupid idea at all. Of course it isn't *practical*... ie you are never going to make these wheels *light* for the amount of work it will take, but it will be an interesting experiment.
Spoke beds are thick to take spoke loads, but are only highly stressed right around the spoke. There is a lot of extra material in this location in between spokes that can be safely removed... that is why many wheel manufacturers in fact do this. If you can't machine easily, then drilling will work... but this must then be covered with some sort of light tape or composite if you want it to make sense.
Sidewalls are usually quite thin, but there is a limit to how thin they can be extruded and still resist buckling when the rim is formed into a hoop. AC420 rims have sidewalls that are machined after the rims are extruded and formed. So you could also experiment with drilling holes on the sidewalls.
The "web" that joins the brake tracks together is quite thin already, but 36h rims seem to get along fine by perforating that quite a bit more than a 16h rim... plus the rim tape will cover that part.
What prompted me to think of this is that I want to get a 16h Kinlin XC280 rim, and none of the distributors want to carry them. Can't get a blank and drill my own holes either, so I'd have to get a 32h rim and have extra holes to cover... or do something completely different.
If I have to cover holes anyway, then why not drill a bunch of holes to optimize the structure, and cover it all with a thin layer of carbon? Sure, a lot of work... but potentially a stronger, lighter, and prettier rim all at once...