I need to replace the 26-inch wheelset on my '92 Ellison tandem (all aluminum frame). The rear spacing is 135mm and the front spacing is 110mm. I currently run Shimano Deore LX caliper brakes, but would like to upgrade to a solid set of disc brakes. The frame is setup to support disc brakes and has integrated disc brake mounts. I've done some searching and can't find wheelsets with the narrow spacing I need, disc compatible or otherwise. Do you have any suggestions on where I can purchase a new set of wheels with the narrow spacing needed for my build?