Bicycle Mechanics - Is an clamp on road derailleur inferior or superior to a braze on version + adapter?

Is an clamp on road derailleur inferior or superior to a braze on version in conjunction with braze-on clamp adapter (in a road bike who does not have a braze on holder in the first place)?
Feedback appreciated

Properly set up, there should be no functional difference. During set-up, however, the adapter will give you one more variable that could possibly go wrong, although in my experience you'd have to screw up pretty bad to get it wrong.

Otherwise, the clamp-on derailleur might be slightly lighter than a braze-on-derailleur + adapter, but nobody in the world could actually notice the difference.

I don't think you'd ever notice the difference. Personally, I wish the component manufacturers would just make every FD braze-on and include a clamp.

What is about the argument to be able to twist the derailleur setup (with a little shim) on the two piece (derailleur plus adapter) setup to adapt the curvature of the front derailleur better to smaller chainrings (46 or 48) in cyclocross. On the contrary, I don't like to have this two piece setup in cyclocross!
The other thing I came acrross is the ability to attach those new design chain catchers which I think are superior to older style chain catchers - those also require a two piece setup unless you want to accept two clamps next to eachother?
http://www.acecosportgroup.com/shop/k-edge-chain-catchers/road-braze-on-triple-chain-catcher.html

Once the frame design goes wild as Many Carbon frames are no longer round tube, You got no choice,
and don't even think about a chainring size change more than a tooth or 2.

What is about the argument to be able to twist the derailleur setup (with a little shim) on the two piece (derailleur plus adapter) setup to adapt the curvature of the front derailleur better to smaller chainrings (46 or 48) in cyclocross. On the contrary, I don't like to have this two piece setup in cyclocross!
The other thing I came acrross is the ability to attach those new design chain catchers which I think are superior to older style chain catchers - those also require a two piece setup unless you want to accept two clamps next to eachother?
http://www.acecosportgroup.com/shop/k-edge-chain-catchers/road-braze-on-triple-chain-catcher.html

I have one like this on my CX bike. It just uses a hose clamp to attach it to the seat tube under the FD. It set up very easily and I don't even notice it.

http://www.probikekit.com/_img_200x256/K1108.jpg

I have one like this on my CX bike. It just uses a hose clamp to attach it to the seat tube under the FD. It set up very easily and I don't even notice it.

http://www.probikekit.com/_img_200x256/K1108.jpg

I have used this type before. However, it doesn't work on many carbon frames which loose roundness in their lower seattube part. That is very the beauty and usefuslness of the new chaincatcher (mentioned in my post above) comes in (and were the brace-on adapter screw is needed).

The advantage of braze-on/glue-on/rivet-on derailleur mounts is that they can be fitted to non-round tubes. The disadvantage is that they may restrict the range of chainring sizes you can use.

Clamp-on front derailleurs are more versatile in that they can be positioned where you need them, but they only work on round tubes.

If you have a round seat tube there's no compelling reason to use a braze-on/glue-on/rivet-on derailleur mount.

My preference is for a braze-on type front derailleur plus the proper adapter clamp for three reasons:

1. Braze-on front derailleurs are less expensive than built-in clamp types and the adapter is a one time purchase.

2. When you strip the bike down for an overhaul you can leave the adapter in place and the fd reinstalls aligned just like it was before you removed it.

3. Not all models of clamp-on front derailleurs come in all clamp diameters but they all come in a braze-on model.

As noted, these only work on round seat tube bikes, which all of mine happen to be.

The biggest problem with braze-on derailleurs is that front derailleur performance is at the mercy of the bracket. I've seen flimsy brackets on very, very high end carbon bikes that allowed so much flex that a clean shift was all but impossible. Clamp on allows the derailleur to function more accurately. :thumb:

Sometimes they're the same.

Somewhere around here I've got an Ultegra equipped bike which came from the factory with the front derailleur bolted onto a separate seat tube bracket. I've owned and ridden that bike for over 10 years and have never felt the need to change it.

I prefer the braze-on FD + clamp combo more because over time with FD adjustments, it damages the seat-tube less. Every time I have to slide a one-piece FD up and down or rotate it to fine-tune, it leaves a little clamp mark on the paint. This was especially apparent on one bike where I had fitted different front-chainrings for road-race versus TT use; after a couple of swaps, there was annoying marks above and below the clamp. With a 2-piece design, I place the clamp in the middle of the range I would move the FD. Then I just unbolt the FD and slide it up and down the clamp as needed without disturbing the frame. This is more distressing on a CF frame.