Chainring teeth divided by cog teeth, times wheel diameter in inches. The number is the size of the penny-farthing wheel that would match, which is why the unit survives at this shop.
Monsoon Cycles, Colorado Springs · Updated August 16, 2026
= 77.6 gear inches
Track riders still talk in gear inches because it is the most honest single number for how hard a fixed gear feels. Mid-70s is a classic street fixed gear; 90 and up is a velodrome sprint gear; a loaded tourer's low gear can dip under 20.