Just a small cog in a big cassette

A small job — Change cassettes from a Ultegra 11-23 to a 13-26.
Step 1: Remove old cassette. Oops. Parts spilled everywhere, but no worry, Shimino has a handy guide online for spacer and cogs. But wait, what are these small clips? American Classic, the hub maker also has an online guide explaining (sort of) the weird little clips. And explaining (sort of) the need for 0, 1 or 2 tiny spacers behind the largest cog. I think I get it...
Step 2: Thank the bike gods the new cassette went on easily and seems to work.
Step 3: Wait for the rain to stop before taking out the new bike.

New wheels, gears

My new - new to me at least - eBay Mavic wheels arrived today. The cassette, chain and the tools I ordered arrived yesterday. I have way to much to do, so of course I immediately installed the whole mess.
Cassette: Easy.
Chain: Easy on. Whoops, missed threading it through a hidden part of the derailleur. Taking it off, re threading it and reattaching it was a pain. But it's all better now. It's shiny, quiet and shifts like a dream.
Now my Mountain bike is my fine commuter bike, at least in theory. Giddy up!