Bicycle Mechanics - Front Derailleur clamp confusion

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View Full Version : Front Derailleur clamp confusion


bianchi10
09-18-12, 03:41 PM
I guess I am a little confused after looking at my FD clamp. I'm looking at my FD and I see where the bolt tightens the clamp, but after looking at the "ratio" or kcnc or other brands I dont see where the front derailleur actually mounts to the clamp????

http://i164.photobucket.com/albums/u30/blknslvrgsxr/20120918_142602.jpg

http://i164.photobucket.com/albums/u30/blknslvrgsxr/61287.jpg

Do I need one like this?
http://i164.photobucket.com/albums/u30/blknslvrgsxr/zirbel_xenith_front_derailleur_600.jpg


veggie
09-18-12, 03:50 PM
What exactly is your question? Do you have a braze-on derailleur of a clamp on? If it is a clamp on, you cannot separate it from the clamp.

bianchi10
09-18-12, 04:06 PM
From what I know (which is little about mechanics. I just started doing things on my own) what I have in the picture is a clamp on. I was under the impression that braze on is the one that is "bolted" to the frame. The clamp I have for my bike is heavy and I'm trying to reduce the weight on it.


FBinNY
09-18-12, 04:19 PM
Some FD's are integrated with the clamp, like the one in the first picture.

Others are intended for braze-on, and use a separate clamp like the ones pictured below. The Braze-on adapters can be one-screw types like the black one where the derailleur mtg bolt also closes the clap, or 2 screw types, like the red one, where the clamp is mounted and a separate screw is used for the derailleur.

So you need either no-clamp, or a 1-screw or 2-screw clamp (your choice).

bianchi10
09-18-12, 04:39 PM
the first picture is mine. so....I cant swap out that clamp?

cny-bikeman
09-18-12, 05:20 PM
It appears to me that your derailleur is integrated with the clamp, so you would have to get a lighter clamp-on derailleur. As for reducing weight, with the lightest derailleur available you would save probably 50 grams or so. If your goal is to brag about how light your bike is or how much weight you took off then go for it.

But if your goal in any way is to improve speed or performance then forget it and just ride. You could spend dozens of hours and hundreds of dollars to shave 4 lbs/1800grams (a huge amount) off a 20+lb bike, which at speed would gain you less than a 1% advantage, and at best about 2% on a pure climb.

The catch here is that you have to subtract from that benefit the amount of speed you lost from the hours spent researching, ordering and installing the weight weeny parts instead of riding. Also, if just one of those lightweight parts fails on a ride you will quickly lose all the minutes you saved.

bianchi10
09-18-12, 05:32 PM
Its for bragging rights. I wont sacrifice quality of ride for weight but if I can a good amount of weight over time and keep performance at its best, that is my goal.

CACycling
09-18-12, 05:35 PM
Just buy a lighter clamp-on FD. I doubt a bolt-on with seperate clamp is going to be lighter.

FBinNY
09-18-12, 05:51 PM
the first picture is mine. so....I cant swap out that clamp?

No, your have a clamp-on FD, and the clamp is built in.

bianchi10
09-18-12, 06:11 PM
ok good to know. glad I found out before I proceeded to buy. thanks for the help guys!