Is there such a thing as an extended length brake pad holder. Basically I'm looking for something that would turn short-reach brakes into long-reach brakes.

I bought a set of brakes (Sram Apex) for my single-speed commuter, only to find that the reach is too short and the brake pads rub against the tire sidewall (about 1mm of pad-tire rubbing in the front and approximately 3-4mm in the rear; doh!). I was thinking that if there were brake pad holders that dropped down a little farther, it would basically turn these short reach calipers into long reach calipers. I did a bit of searching, but couldn't find anything that would work. Any ideas?

I could probably fabricate something myself, but ideally I'd be able to buy something. If my brakes fail at 20mph on Michigan Avenue in Chicago, I'd like to be able to blame someone other than myself.