I've been learning a bunch of the info in this thread gradually and from all around over the last 6 months or summat.
I started out with My Identiti Dr Jekyll, I was retrialing the 24" wheels I've never been totally sure about and 12-25 gears were pointless really on those wheels.
DMR kit and sliding dropouts made this easy, now on 26" wheels again I might even like it when I get to the hills again feels good on road and mucking about, running summat like a 16 40 (or38?)
I 'upgraded' the gears on my 8x1 Revolution Courier Race to the 12-25 and Tiagra mech, then one day chain jumped off and slipped on leaves!
It as flat as a supermodel here so I used one gear only on my commute to get the right one, after some testing and calculating...
Bought an On-one doofer (its al right for the money i suppose, and Max at londonfixieshop sold me a spacer kit and 16t Shimano DX cog
I'm sure the old crap chain ring was ramped
and quite worn, new Thorn item was ace compared
Bit more testing and a proper SRAM PC1 chain, and my wishes came true...
Bit tight but rides fine!
so far so good, exactly right gear for my short commute 16 46
Was gonna do my Raleigh next but discovered this old gem has sliders like old racer frames, so making this into a SS/Fixie is next plan. what ya reckon?