The golden ratio is ~1.6



140/ 84 = 1.6
84/ 56 = 1.5

160/ 100 = 1.6
100/ 60 = 1.6
^This applies for the shank + blade, and also for the grind (A very full hollow, or frameback)

Essentially, a 5/8 razor with 3 and 2/8 blade length. Which seem pretty common.

So if you were to continue using the golden mean, where about would the pivot be placed?