Albert P, who comes on some of my rides (and can ride rings around me, although he's too polite to actually do it when we're out together), had a triple front chainring on his Cannondale. He never used any but the middle ring, and thought a double would give him the advantage of better use of the full range, so he bought some parts and we made a date to change it out.
I thought it would take three hours; it took six. And, while the bike left in more-or-less rideable condition, it was a disappointing experience.
First, the bottom-bracket removal tool I have was the wrong size for the modern Shimano Hollowtech bottom brackets, and the left crank uses a proprietary star tool for attachment. Well, it will require a trip to a bike shop that doesn't open for two hours, so we'll install the rear derailleur first. Huh? There's no "B" screw; that's funny... OK, then we'll do the brakes. Oh, damn; you can't get the rear wheel on with the derailleur in place because of the stupid adjustment. OK; remove the derailleur; put the wheels on; put on and adjust the brakes.
There's a spot on the rear wheel that has a bind. While Albert goes to the shop, I true the rear wheel to fix it (Albert likes his brakes TIGHT).
When Albert got back from the shop, we popped in the bottom bracket and the cranks, lowered the front derailleur, installed the chain... wait; the chain droops. It turns out there are metal fingers that have to be aligned where the "B" screw would usually go; that fixed the droop. Adjust the front derailleur; that works... wait; no it doesn't. Something on the front derailleur popped, and now its range of motion is so limited that it won't cover both rings. Albert had the idea of using the other derailleur (it was only a year old); which works (I was too busy feeling disappointed and useless to think of it).
Adjust front derailleur. There's a terrible noise on the large cog; what on earth is that? Albert notices that the cog is hitting the jockey wheel; that means there MUST BE a "B" screw adjustment. Albert notices a screw sticking out into the atmosphere that doesn't seem to have any other purpose; it turns out to be the correct one. Nice!
Finally it's working. The rain has let up enough for a test ride; when Albert gets back, the left shifter won't drop the chain to the small gear. It turns out there's an interference in the levers; if you tap the lever, the interference clears... but it's not elegant. I think it's an issue in the shifter. It may pass with time; in the meantime, I'll look for information about an adjustment to the shift levers.
The bike is rideable... but I'm not happy about it.
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