there is some excellent info disseminated in this thread, linked with the one i started a few months ago here:
https://forums.thepaceline.net/showt...ht=big+waiting
Though, the lengths of the threads and the paragraphs in those threads only proves the issue - more and more people are interested in non "standard" (53/39 or 50/34) gearing these days, and these home brew solutions are cumbersome at best. scouring the internet and UK suppliers for suitable parts may be OK for us bike nerds, but too cumbersome for most people to want to bother with.
i'm reasonably certain that shimano and/or sram will see the light and offer some expanded gear ratio offerings (at the chainrings, not just the cassette) soon.
please, and thank you!