Originally Posted by
jwhearn
Most of the info I could find in forums was about going from Triple to Double. Not sure why you would want to do that, but anyway I want to know if I can replace my double compact crank (DA 7900) with a triple (probably Ultegra). I have DA 7800 shifters and I don't care about getting to the big ring so I'm thinking I could use my current shifters (just limit the FD to reach the middle at it's farthest). Would this work without changing anything but the crankset? This would be a temporary thing - to get through some upcoming mountain races, then I would put my double back on.
Thanks.
because it saves weight and improves shifting performance.
what you're talking about might work - i'm not really sure. but...if you have a compact crank already, your small ring is probably 34t. small ring on a triple is usually 30t. 30t is obviously lower, but most people could probably get up most hills with a 34t chainring if they used the right cassette. what cassette are you using now? couldn't you just get a cassette with some larger cogs? that would be much easier, assuming your RD can accomodate it...and maybe even if it can't. getting a new cassette and RD is probably still cheaper and easier to install than a new crank.
EDIT: just for reference, from sheldon brown's gear-inch calculator, 30x25 (on a triple with 11-25 cassette) would give you 31.5 gear inches vs. 31.9 inches for 34x28 on a compact with 11-28 cassette. clearly a triple with big cassette would be even lower, but if you're talking about one or the other, the cassette is easier to change.