[TheForge] Source for flat track sliding door wheels?

[Douglas C Wilson]

I am building hardware for sliding doors for the shop. The track is 1/4 
x 2 bar on edge. I would prefer to not have to build the wheels/casters 
that run on the flat bar track. Lots of places sell the hardware as a 
unit but will not sell wheels. I have looked at casters for angle iron 
V-track and at wire rope sheaves but neither have the narrow and deep 
profile groove of a flat track wheel that keeps it from jumping the track.

Anyone know of a source for these specialty wheels?

Thanks,
Doug