'F' for Flyer if I'm not mistaken - don't ask me to describe the relative differences - I don't know as it's just an (un?)educated guess taken from memory, and this list from an advert in a 1957 copy of Cycling magazine. An interesting insight into the relative cost of the saddles in the range as well (in good old fashioned UK L.S.D. in this case shillings and pence)
B15 Std. (32/6) B15 Narrow (32/6) B15 Flyer (32/6) B15 Swallow (35/-) B17 Std. (45/-) B17 Narrow (45/-) B17 Flyer (45/-) B17 Sprinter (45/-) B17 Competition Standard (46/-) B17 Swallow (67/6)
also in the same magazine is an advert for the generically similar but considerably cheaper Lycett saddle L.15 Swallow (25/-) introduced in 1956.
Bob Reid Stonehaven Scotland.
http://www.wheelscycles.co.uk
> From: Huthornton@aol.com
> Date: Sun, 29 Oct 2000 16:11:38 EST
> To: classicrendezvous@bikelist.org
> Subject: [Classicrendezvous] Brooks B17F Saddle
>
> Re the recent correspondence on Brooks saddles, does anyone know what a B17F
> is? I had never come across one until acquiring one on a 1950's Raleigh
> track bike. It is a bit wider than a B17N, but I have no other B17's to
> compare it with. What does the "F" stand for? There are no bag loops and no
> sign of any having been removed, but that is not to say that it might not
> have had them at some time.
>
> I need a good B11 -- has anyone got one for sale?
>
> Hugh Thornton