Double to Triple conversion
 

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.

I went from a standard double to a triple and now want to go to a compact double. I don't have much knowledge with Shimano but it was easy with Campy. With Campy, I didn't need to change the shifters because Campy uses the same shifters for both doubles and triples for 10 speed at least. All I needed to do is change the crank and front dr.

The advantage of a compact for me isn't because it weighs less or shifts better but because the gearing is more useful for me.

If you are considering a triple for "mountain races", you need to climb more.

Change the cassette.

You could buy a double mountain bike crankset.

In my view the biggest problem with doing this is that you will change the stance width of your bike for just a few hard rides. For me a 10mm change in width each side is the difference between serious pain and absolute comfort. I may be a little unusual in that respect but have you ever tried it? I use long speedplay spindles to get comfortable and wouldnt change anything up front if you paid me

Please don't add a triple, they are worthless with today's gearing options. I just upgraded to a double with my new bike and have the exact same gear bottom end and a way way higher top end even with a 39/53 standard crank.

This sounds like the best option if you don't need the large gears, you could get something like a 26/39.
I bought a 9 speed triple mountain bike crankset for $50 bucks that's held up as good as any other crankset I've used, so you could probably go really cheap if you wanted to.


They allow you to have a tighter cassette, or much lower gearing. You can go all the way down to a 24T on a triple.

How many balls does it take to shift on to the "big ring"? I only wish that when riding my ten speed through a field full of wet goose **** I had thought about what ****ing ring I was in...