Originally Posted by
Al1943
My favorite 9-speed cassette is a 13-26 that I put together from various parts including the middle cogs from an XTR. Very light with close ratios.
I did about the same thing to build a 13x27 9-speed cassette. I started with a 12x27, discarded the 12 and 13T cogs and added a 13T first position cog salvaged from a 13x25 cassette and added a single 16T cog and spacer.
The problem with doing that now is getting a 16T cog of any "speed". They just aren't available any more and took some real scrounging back when I did this about three years ago.