Bonhams has announced the addition of two new highlights to its motorcycle auction on April 25 at The International Classic MotorCycle Show, Stafford, UK.
They will sell alongside the first motorcycle ever made - an original circa 1895 Hildebrand & Wolfmüller.
The ex-Francis Williams, Basil Keys Norton-JAP 996cc Mk1 'Saltdean Special' Sprinter (estimated at £90,000-100,000) and the 1938 Brough Superior 982cc SS100 (estimated at £110,000-130,000) are both are expected to attract much enthusiastic bidding on the day.
The ex-Francis Williams, Basil Keys Norton-JAP is a historic sprinting motorcycle with outstanding stature and competition pedigree.
This example is the first of three Norton-JAP sprinters conceived and built by Francis J Williams and it was the machine to beat in its day. In 1959 it was sold to Basil Keys, himself a dedicated sprinting enthusiast, who went on to win many events on it with the name Basil Keys becoming synonymous with the Brighton Speed Trials.
In 1959 he broke the course record at Brighton, covering the standing-start kilometre in 21.59 seconds at an average speed of 103.61mph.
Meanwhile, the Brough Superior SS100, the legendary superbike of motorcycling's between-the-wars 'Golden Age', Brough Superior - 'The Rolls-Royce of Motorcycles' - was synonymous with high performance, engineering excellence and quality of finish.
That such a formidable reputation was forged by a motorcycle constructed almost entirely from bought-in components says much for the publicity skills of George Brough.
But if ever a machine was more than the sum of its parts, it was the Brough Superior. This example has only had four owners and is offered for sale by a Brough Superior Club copy works record card, a Tester's Road Report and an old-style buff logbook issued in April 1955.
More than 500 lots of motorcycles and related memorabilia at the sale will range from an 1894 Hildebrand & Wolfmuller to a 1950 ex-Ernie Thomas Velocette KTT Mk VIII, and a 1950 Vincent 998cc Series-C Rapide to a 1974 Laverda 750SFC Production Racing Motorcycle.
"This is without a doubt one of the best line-ups of collectors' motorcycles ever offered for sale at The International Classic Motorcycle Show," said Ben Walker, Head of Bonhams' Motorcycle Department.
"There is something for everyone, the sale encompassing all genres and areas of collecting. Given the number of important and historic machines on offer I expect the printed catalogue to become a collectors' item in its own right!"