Originally Posted by
Jawn P
The road hub is the same thing as the track, just with an extra 10mm spacer on the nondrive side.
I'n not an expert on these things. But Speed Goat lists different "center to flange" measurements between the track and 130 hub. Maybe they are wrong.
I am proficient in measuring, and my stock bike with a Surly 130 hub and Surly cog is about 47mm at the cog and 47mm at the chainring. Certainly not close to 42.64.