FG 7.9 to FG 38.1

Component 

Thread type 

Outer diameter (mm)

threads (TPI)

Use / Special feature

front axle

FG   7.9  (5/16")

7.94

26

front wheel hubs

Rear axle

FG   9.5  (3/8")

9.53

26

rear wheel hubs (standard)

Rear axle

FG 10.5 

10.5

26

special hubs / gear hubs

Bearing cone 

FG 14.3

14.29

20

bell bearing shaft (9/16")

Fork Shaft 

FG 25.4  (1")

25.4

24

Classic 1 inch Forks

Fork tube

FG 28.6  (1 1/8")

28.6

24

MTB/Trekking Forks (thread)

Fork tube

FG 38.1  (1 1/2")

38.1

24

Extremely rare 1.5" Forks (thread)