How to work out your axle length


Axle Dimensions

Huntsman Products axle dimensions

Dimension Name Description
TT Tip to Tip Total length of axle from end to end
FF Face to Face  Distance from one wheel face to the other (track width)
CW Chasis Width  Distance between outside of chasis rails
CF Chasis to Face  Distance from ourside of chasis rail to wheel face
TC Tyre Clearance  Distance between outside of chasis rail to inside wall of tyre
AS Axle Section  Steel section of axle (45 square, 50 rounds, etc)
TW Tread Width  Tread width of tyre
BS Back Space  Distance from inside tyre wall to wheel face


Axle Selection
Before selecting an axle, you will need to decide on the following:

  • Trailer ATM / GTM
  • Single or Tandem axle
  • Choice of brake type
  • Type size and stud pattern

Based on this information, Huntsman Products will recommend a minimum axle section, hub / disc / drum size, bearing size and axle length for your trailer.

FF = CW + (2 x TC) + (2 x BS)

TC is minimum 45 mm
BS is measured or calculated from tyre size

For a CW of 1200mm, Tyre size 205/75R15 (no offset),

FF = 1200 + (2 x 45) + (205) = 1495mm