Originally Posted by
colnago62
The spacing of the rear triangle for a track frame is much more narrow than a modern frame. I want to see it is the same spacing as 5 speed, I think.
Most track frames these days use 120mm OLD spacing; the same as vintage "10 speeds" with a 5-cog freewheel. Older (pre-1970s, mostly) track frames might have 110mm OLD spacing. But if this is a steel frame, it's not difficult to re-space it to accommodate wider rear hubs.