# 3x front derailleur as a 2x



## ParadigmDawg (Aug 2, 2012)

So, I had 3x chainring on my road bike and wanted to be like the cool kids and switch to 2x.

My bike mechanic said I could use my 3x front derailleur but a 2x would likely shift better.

Being "cheap" I decided to try the 3x first. I ran to Performance Bike- since I had a lot of their points saved up. They had Ultegra FC-6750 Compact Crankset on sale for $239 and I had $150 worth of points. 20 minutes after getting back home I had the cranks on and the 3x front derailleur adjusted and hit the road. It shifted just as smoothly as ever so I am just going to keep it this way.

You guys probably already knew it would work fine but I thought I would post this just in case.


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## AndrwSwitch (May 28, 2009)

Actually, I agree with your mechanic. While it does work, switching to a double would be a little more conservative choice and IMO having a double FD is a good chunk of the reason to switch to a double crank. I had a triple FD on my 'cross bike briefly between switching it to a double crank and getting the double FD. A little more finicky to tune, not quite as forgiving of weird chainline. And the cage still has a stepped shape that I thought might be more conducive to dropped chains when I remount less gracefully than I should.


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## heybrady (Jul 3, 2011)

AndrwSwitch said:


> Actually, I agree with your mechanic. While it does work, switching to a double would be a little more conservative choice and IMO having a double FD is a good chunk of the reason to switch to a double crank. I had a triple FD on my 'cross bike briefly between switching it to a double crank and getting the double FD. A little more finicky to tune, not quite as forgiving of weird chainline. And the cage still has a stepped shape that I thought might be more conducive to dropped chains when I remount less gracefully than I should.


Is it the actual FD that is better for a double, or is it the shifter? I would think the FD would be the same, just have a greater range of swing (just coined that term) to cover 3 rings. Is the cage actually a different width?


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## tednugent (Apr 26, 2010)

heybrady said:


> Is it the actual FD that is better for a double, or is it the shifter? I would think the FD would be the same, just have a greater range of swing (just coined that term) to cover 3 rings. Is the cage actually a different width?


Shimano does have a triple specific and double/compact specific front derailleur.


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## PoorCyclist (Oct 14, 2010)

I am doing this on my MTB double crank, 3x shifter 3x FD with the high limit dailed back. I initially got chain suck a few times using an old chain on new crank, but now I see no need to change it. 

The concern, if any, would actually in the shifter because it is indexed.. in theory a triple shifter should be shifting a tiny bit less than a double between 2 chainrings. in practice it works.


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## ParadigmDawg (Aug 2, 2012)

PoorCyclist said:


> I am doing this on my MTB double crank, 3x shifter 3x FD with the high limit dailed back. I initially got chain suck a few times using an old chain on new crank, but now I see no need to change it.
> 
> The concern, if any, would actually in the shifter because it is indexed.. in theory a triple shifter should be shifting a tiny bit less than a double between 2 chainrings. in practice it works.


 My mechanic did say it wasn't indexed now but I am not 100% what that means in relation to this.

My initial feedback was after a pretty casual ride with the wife. On a solo ride, last night, at quite a higher pace and a lot more shifting involved, I would have to say that the shifting isn't as good as it was. Maybe I will try a 2x.


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## AndrwSwitch (May 28, 2009)

heybrady said:


> Is it the actual FD that is better for a double, or is it the shifter? I would think the FD would be the same, just have a greater range of swing (just coined that term) to cover 3 rings. Is the cage actually a different width?


Take a look at your front derailleur.

Take a look at a double front derailleur.

The cages are very different. The triple cage has an extra step and a whole lot more inside plate. This is the pertinent difference. Actually, I still have a triple shifter on the bike I switched to double. I use the two lower-tension positions and the limit screw on the derailleur prevents me from shifting into the highest.

The derailleurs have pretty much the same swing, normally referred to as "pull ratio" or they wouldn't be interchangeable.


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## ParadigmDawg (Aug 2, 2012)

I actually changed to a double front derail yesterday and it does shift better.


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