3′ 9″ diam., disc. 4½″ apparent tread.
Hub 12½″ face dia., 1″ out from the front and 1¼″ from the back of the tyre.

Source: B1 tender measured direct at Loughborough in 1995.
Works drgs. 114719, 114888 (1:8 and full size) for tender wheels for J39.

Casting: 142.9 mm tread dia., 111.3 i/d. Hub 3.2 mm out from the tyre.
The back of the casting is flat, but recessed from the tyre.

7¼″ gauge price list . Stock