Triple to Double
 

I currently have my bike set up with a Shimano 105 triple crank, 9-spd cassette. I'm considering purchasing an ultegra double crankset, last year's model that is a 9 speed. I have two quick questions here:
1) can I use crankarms (just the arms, not the rings) for a double crankset on a triple, if I decide to keep the setup as a triple. The bcd is 130mm. I've recently upgraded the 52 and 39 rings to ultegra, but am still rockin' the 105 crankarms.
2) if I decide to use the entire crankset, changing the setup from a triple to a double, what other components have to be changed, ie front derailleur, etc.

Thanks!

If you want to change to a double, you'd have to replace the front derailleur, the left-side brifter, and the crankset obviously. If you're just going to 9 speeds again, I would encourage you to think it over a little more - the performance gain you would be able to get from a properly adjusted 105 setup to Ultegra is minimal. And you'd have to spend a lot of money on the whole conversion; the new STI lever will cost you around $100 and the crankset around $150, not to mention a new FD for $30-40 or so. I'm not too sure what you were asking in your first question though, so I could be missing something.

I think nashbar is having a sale on the 105 stuff but it's still pricey... why double? The 105 crankset on nashbar is $90 rightnow, but the brifters are 150 plus another 30 or so for the f. der so it'll be costly. I don't think going ultegra is really worth it right now unless your getting a deal on it.

BTW, you coming up for the DUMBO race?

All you REALLY need to replace is the bottom bracket and crankset. The shifters and front derailer will work fine. When I did the switch, I replaced the rear derailer as well, from a 105 long cage to an ultegra short cage.

I thought the newer brifters would work for double and triple.

Why are you thinking about going to a double?

performance has a good deal on the ultegra double crankset. all I really want is the crankarms, but they don't have the triple crank arms available. so back to question 1) above, can I use just the crankarms?

no go for dumbo. I already have a ticket for boston. I need to plan ahead better.

Maybe try the 'live chat' on the perf/nashbar website---they should be able to check it for you.

Wait, why do you want new crankarms but not chainrings? Most have to replace the rings, not the arms.

Wait just a min here. What length cranks do you have? I am rocking Ultegra 6503 (9 speed triple 172.5mm) cranks on my Marin commuter but it is an all black bike and if your 105 crank arms are black...hmm maybe we could swap. :D

A proper swap to double would need a new BB as well as the crank as the spindle length is 108.5mm rather than 113mm. You DON'T need to get a new FD or brifters...if you want you could get the FD but you don't really HAVE to. The brifters are a non issue they work for both there is no 2nd PN in either the 105 9 speed or 10 speed for that matter.

see above, chainrings recently replaced....

She's tall. 172.5 probably wouldn't be far off.

the crankarms are 175. I like 'em long!! However, they're silver.
so, just to verify, I think my second question may have gotten lost here....can I use the crank arms on the double? leave everything else as is, and swap out only the crankarms?

I'll use the rings on another bike that's already set up as a double.

I'm 5'7 rockin 180mm cranks on one bike.. Just call me mini Mig. Kinda sucks on the hills, but on the flats...whooowhee!

You can, if you can find just the crank arms to buy...