Rivendell on IRD 8/9spd cassettes

From Riv

"We’re now carrying IRD cassettes, 8-speeders and 9-speeders, made, we hear, by

Shimano’s subcontractor and to the same quality standards."

"Anyway, the great thing is we got to pick the ratios, and although it’s hard to go way wrong with a cassette, there is a theoretically-smarter-than-usual way to go about it, and that’s what we've done. The cog gaps increase as they cogs get bigger, so the effective change in gear or effort makes sense. PLUS, we got 12t top cogs, which are more useful than 11’s, and 34t low cogs, which split the difference nicely between a 32 and 36."