Many bicycle companies copied the frame design of the R20, including in estern Europe countries. I have one already posted here in the bike forums. Are you making any reference to these "copy" bicycles?
Morrisson NZ deemed that the Raleigh Twenties made in New Zealand didn't need the extra triangulation found on the Twenties made in the UK. I guess because so much of the riders weight is back from the bottom bracket then the rear triangle is sufficient, the cross bar and head-tube almost floating out in front like the runners on a snow-mobile. We used to jump them pre-bmx (well pre-affordable bmx) and i've never seen one broken. Maybe the NZ steel is different as well. Would anyone know how to tell what type of steel is used? Also the geometry of the 20 frame is exactly the same as the grifter and chopper ( bar a few extra tubes)...the raleigh 20 is a truly ultimate stripped back and totally functional frame design.
RIDE ON MY RALEIGH BROTHERS!!!
My 20 has the extra tubes. The frame tubing decal is just still readable. Raleigh Industries 20-30. There is another line of text below which I cannot read. Could be something like Cornwall Gasworks. Or it could be Chrome Alloy.
Maybe if the Kiwis stepped up to the lofty 4130 tubing, the extra tubes were redundant.