(Click for full photo)
1921 - 1930 Sunbeam Royal Sunbeam 1923 Royal Sunbeam
Frame no. 141812.
(according to Pinkerton et al - "Sunbeam Cycles, the story from the catalogues, 1887-1957" - no.140107 was sold on 25.5.1923 and 142400 0n 23.3.23 so it probably dates from that year)
Proportion in bicycles is a subtle matter, generated by lengths and angles: to my eye, this is the epitome of the roadster bicycle, with its 26" frame and 28" wheels - it is certainly handsomer than another bike I have, with 28" wheels but only a 24" frame. I think the length of the head-tube is critical.
The bike is fitted with the "standard" Sunbeam 3-speed hub introduced in 1913 to supersede the Newill "stepped" hub pictured elsewhere on this site. It is effectively a clone of the BSA 3 speed, which was itself a version of the Sturmey-Archer X type made under licence.
This hub has two notable virtues compared to the usual Sturmey-Archer article: first, it is always in some gear, so no risk of groin-crippling pedal slip; second, the wire is slack in low gear rather than top, so that if it fails, it is easier to get home. Why Raleigh (who effectively owned S-A) did not use it on their bikes is a great mystery.
It also has "Roman rims", first made in 1897 and fitted to Sunbeams at least as early as 1902 . These were made of a patent alloy of aluminium invented by Dr Reinhard Isidore Roman, and called "Romanium"
The relevant patents can be viewed at
ep.espacenet.com/numberSearch?locale=en_ep
by keying in GB189907786 (which relates to the making of the rims)
GB189806730 (relating to the use of alloys in bicycles generally)
and GB189806729 (the actual composition of Romanium)
