Collin2424

I know this seems like a dumb question and I can understand how a derailleur designed for a double can't work on a triple, but what about the other way around? I bought a Centaur Triple front derailleur and I've changed my mind for cranksets. I want to use a compact double, so can this derailleur work for me? Will I see any disadvantages?

Thanks a million for saving me from my own second-guessing!

-Collin-

fietsbob

Triple and compact double FD have a deeper back plate, to work with 10 +

tooth/radius differences.. in that they are similar.

Campag specific , brand new stuff, your guess good as mine,
the 80's wide step doubles work as well on triples.

ran a wide step in the 80s,52/36, used the common road double FD back then.. younger lighter and stronger.

Buy it and report.

FBinNY 

Think about this for a moment. You have a triple crank and FD, but rarely use the granny.

Now that you've answered the basic question for yourself, there may be complications like chain line, outer chainring maximum size, and a few other details which might affect performance. But in most cases yes a triple FD can handle double chainrings.

HillRider

That's helpful, isn't it? A cryptic answer unrelated to the question the OP asked. Of course it will work with barend shifters. Anything will.

To the OP: what shifters are you using? If they are 2006 or earlier or 2009 or newer Ergos, you should be fine as the front shifting is more a ratchet than true indexing and you can trim the fd at will. If your brifters are 2007-2008 Centaur with the "Escape" and "QS" mechanism, they should still work the trim options are more limited.

DaveSSS 

Well, it will work, but not the greatest, due to the chainline difference and chainring size difference. I did this once, just as an experiment. IIRC, it required a lot of clicks due to the wider cage. You should notice it most when shifting from the little ring to the big ring. A triple's big ring is positioned at least 5mm further to the right than a double and the FD is made to handle the extra travel to the right.

A new compact FD that only require 3 clicks would be a far better choice.

Collin2424

Thank you for the information. The shifters are 2010 Veloce and the FD is a Centaur 10-speed. So, it sounds like I should be okay.

Honestly, the QS or non-QS, along with "Escape" really confuses me. I am sure there is a place where I can read about the differences, but it's tough to grasp at first. Anyway, thanks!

-Collin-

DaveSSS 

QS is only a reduction in the dead travel from the left finger lever. All current shifters have it, even though it's no longer worth advertising. The escape shifters have a limited-function thumb button that can only shift one cog smaller at a time and limitations on the FD shifting. Centaur and lower level from '07-'08 had this mechanism and now a similar mechanism (powershift) is being used on 2011 Athena and below.

Collin2424

So since my shifters are most-definitely "Powershift," I'm looking at only one shift at a time from the thumb button? I wonder why that's called an "Escape" function. Really just seems like limited function compared to the other Campy shifters I have (Record 10 speed)

-Collin-

Drew Eckhardt 

I wouldn't bet on it. When I swapped my 50-40-30 triple for a 50-34 compact double I couldn't get my Racing-T front derailleur setup so that it could shift to the large chain ring and not drop the chain on the crank arm. The compact double front derailleur with a different (I think it was a bit narrower) cage works fine.

DaveSSS 

Do a google search on escapement mechanism. You'll get a rough idea of what it is. The principle is much different than either the ultrashift or it's predecessor.

cs1

Campy CT front derailleurs, non Record/Chorus, are pretty cheap on ebay. I can't imagine why you wouldn't to buy one. Good luck on whatever you choose.

DaveSSS 

The CT specific model is not as desirable as the current CT/std models that work with either compact or standard cranks.

cs1

Maybe so but you can still get them from Ribble in the UK for cheaper than stateside. As far as I'm concerned it's easier and cheaper to use the correct part if available and it is. Good luck

DaveSSS 

The new CT/std FD is the correct part. The CT specific model was dropped several years ago. It does not work as well as the latest model.

Yes, you can buy all Campy parts cheaper from the UK.

cs1

Even the old QS version is available for $25 - $35 on ebay. Sell the old triple to help defray the cost if money is a problem.