This example shows a tyre width of 3.5 mm for Gauge 0 Fine.
For Scale7 remove more metal from the back of the wheel to give a tyre thickness of 3.2 mm instead of 3.5 mm.
5′ 6½″ diam., 18 rectangular spokes, apparent tread 3″, tyre width 5½″.
Hub 15″ face dia., 1″ out from the tyre, pin in line at 12″.
Note the very slight forward projection of the tyre from the inner rim - the tyre was held to the wheel centre by bolts.
Casting: 38.8 tread dia., 35.2 i/d., hub 0.6 mm out from the tyre, pin at 7.0 mm radius.
Casting prices and stock . Australian loco sets, price list
Scan of castings in a set for a NSWGR 4-4-0 Z12.
27 Mar 2013