All very interesting and I suspect someone a lot smarter than me did a lot of maths to create all of this - lot's of variance but principally it's all lead to most manufacturers providing the same options circa 2013 - all seems a long way round to the same destination?!
However, I have noticed Mavic tried to cover both bases with 130 & 144 - I know this as I bought some spare Mavic chainrings on the assumption that they would fit my 631 cranks - but no - they are for the 630 cranks!! that's how simpletons like me get confused
Rick Powell 753 Track / Ribble Gran Fondo / Colnago Asso / 1975 Harry Quinn TT / 1990 Concorde Prelude / Vitus 992 / Keith Coppell Lo-Pro / 1986 KAS Vitus 979 / 1995 Mercian Strada Speciale / 2011 Raleigh GAC Militis 3 ex Graham Briggs / 1995 Ribble 7005 / 1986 Alan Super Record / 1985 MK1 Vitus 979 /
On the bench: Sirius 853 TT / Sun Solo Chrome / Ciocc Designer 84 / Giant TCR0 Pro Compact / Ribble 653 Tourer / Daccordi Lo-Pro / Look KG96 / Bottecchia Equipe / Look KG231 Credit Agricole / Contini Grand Prix / Aende Lo-Pro / TVT / Langdale 653 Pursuit /