wheelbase

wheel +‎ base

wheelbase (plural wheelbases)

1. The horizontal distance between the front and rear axles of a road or rail vehicle.
   • 1937, Robert Byron, “Kala Nao”, in The Road to Oxiana‎:

     Beneath the snow, and after we had left it behind, the road was as greasy as vaseline, as steep as a scenic railway, and often not a yard wider than the lorry’s wheelbase.

   • 1959 February, G. Freeman Allen, “Southampton—Gateway to the Ocean”, in Trains Illustrated, page 91:

     The Southern acquired them because the little Class "B4" 0-4-0 tanks were finding heavy modern rolling stock more and more of a handful, and at war's end the railway had nothing of suitable power but short wheelbase on its books to take their place on the more tortuous of the dock lines.

   • 2023 March 8, David Clough, “The long road that led to Beeching”, in RAIL, number 978, page 42:

     He thought the types of wagons planned (short-wheelbase types) needed reassessment.

Also used as an adjective in combination: long-wheelbase (LWB) and short-wheelbase (SWB).

• track : the distance between the opposite wheels on a same axletree.