Crankarms/set swapping - buying - sizing - anything

[gururug]

I have 10speed 105 and want to try 165mm crank arms.

a) can I just purchase and swap the arms themselves?

b) will any arms (ie ultegra/generic/etc) fit the fsa gossamer crankset I currently have.

c) could a reasonably proficient handyman replace these components without issue (don't need to remove spindle thingy?)

d) do you have to get the whole crankset or can you just get the arms?

e) can anyone recomment cheapish but quality brand and (online?) supplier to purchase these arms.

NOTE: my inseam is 71cm. The cranklength calc says I should have 153.75 carankarms and other sites say "below 5'10 use 170mm cranks on for general (road) racing and
training," if i currenlly have 170 and it feels slightly too long.

It's a new bike I guess shops / manufacturers won't cover a change (have to pay / fit yourself?)



Thanks for the advise in advance'.

[mikesbytes]

a) can I just purchase and swap the arms themselves?
Yes

b) will any arms (ie ultegra/generic/etc) fit the fsa gossamer crankset I currently have.
No, they will need to use the same type of bottom bracket

c) could a reasonably proficient handyman replace these components without issue (don't need to remove spindle thingy?)
Yes, you just need the correct tool, then its dead easy.

d) do you have to get the whole crankset or can you just get the arms?
Don't know

e) can anyone recomment cheapish but quality brand and (online?) supplier to purchase these arms.
Um...

NOTE: my inseam is 71cm. The cranklength calc says I should have 153.75 carankarms and other sites say "below 5'10 use 170mm cranks on for general (road) racing and
training," if i currenlly have 170 and it feels slightly too long.

I'm 5'11 3/4 and I use 170mm cranks. Others my height use 172.5 or 175.

The guide line is 1/4 the distance between the middle of the bottom bracket to the top of the seat following the frame/seat post. Then it boils down to personal preference. Its a guide line not a rule.

[LuckyPierre]

Don't forget, 'swapping crank arms' usually means the whole crank set (most stores only carry complete sets and wouldn't want to be left with the chain rings), and I'm not sure just how compatible a Gossamer bottom bracket would be with other brands. See, there is a reason for my preference for consistency through the groupset!
Just how tall are you? A 71cm inseam seems pretty short - you have to measure your inseam as if you were sitting on your saddle, not from the crotch of your pants. I'm 178 cm and use 172.5 cranks, but I don't know my inseam (in bike terms).
As Mike says, fitting is pretty easy, but you do need a few special tools - crank remover at least, then bottom bracket tools (there's two that you need for 10-speed) if you have to go that far.