I'm learning lots about old bicycles lately ... my wife's new old Hercules has this size of wheel and it's apparently not the same as any other kind of 26" wheel. I'd rather like to replace the front wheel with an alloy rimmed wheel to improve the stopping power in the wet, but options seem limited. In fact, the only option I've found so far is the Rigida RM19 rim from SJS, and a hub, and build the wheel myself - which is one possibility but I wonder if there are others. The current hub needs a bit of TLC itself anyway, so I don't think I want to reuse it. Anyone? I'm guessing the 590 rim is not close enough to any other size that I can just put an MTB wheel in and expect the brake calipers to reach the rim, or am I wrong?