# Braze-on front derailleur with a clamp? Why?



## hobiedog (Jun 18, 2005)

I'm building up a Klein Q-Pro and was curious why frame makers use braze-on front derailleurs, but require a clamp on them. Why don't they just spec. in, or offer, only clamp-ons? Another way to pose the question, why don't they just braze-on the lug, or leave it off and use a real clamp-on front derailleur?

Perplexed,

JT


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## C-40 (Feb 4, 2004)

*braze ons cost more...*

It takes additional time and effort to weld, braze, or glue and rivet a "braze-on" mount to a frame. It's easier and cheaper to use a clamp-on type, but you have to be careful installing a clamp-on or you may mar the paint.

Clamp-on adapters are made so that folks who already have a braze-on FD can use them on any frame. That's one small advantage of a braze-on FD, an adapter clamp can be purchased to make it fit anything. Some adapters even have vertical travel, so they function like a true braze-on mount, but they are not as pretty.


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## bigbill (Feb 15, 2005)

To add to the previous post, they make it easier to set up a compact crankset IMO. Some braze-on hangers don't provide enough adjustment to move the FD down for the smaller big ring. Problem solvers makes a nice black one if want that look or are like me and are allergic to shimaNo. The shimano adaptors do work well.


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## TurboTurtle (Feb 4, 2004)

hobiedog said:


> I'm building up a Klein Q-Pro and was curious why frame makers use braze-on front derailleurs, but require a clamp on them. Why don't they just spec. in, or offer, only clamp-ons? Another way to pose the question, why don't they just braze-on the lug, or leave it off and use a real clamp-on front derailleur?
> 
> Perplexed,
> 
> JT


Shimano does not make all sizes of clamp-on FDs. With some seat tube sizes, the only choice is a clamp adapter and a braze-on derailleur. - TF


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## Mark McM (Jun 18, 2005)

TurboTurtle said:


> Shimano does not make all sizes of clamp-on FDs. With some seat tube sizes, the only choice is a clamp adapter and a braze-on derailleur. - TF


Clamp-on front derailleurs are commonly available in 35mm (1 3/8"). Do any manufacturers make seat tubes larger than this? If not, then surely it must be cheaper and easier to make a shim to fit a regular clamp-on derailleur special diameter seat tube than it is to make a special clamp-adapter for that diameter.


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## terzo rene (Mar 23, 2002)

Mark McM said:


> Clamp-on front derailleurs are commonly available in 35mm (1 3/8"). Do any manufacturers make seat tubes larger than this? If not, then surely it must be cheaper and easier to make a shim to fit a regular clamp-on derailleur special diameter seat tube than it is to make a special clamp-adapter for that diameter.


 35mm is about as big as you can go and still have the front derailleur function properly and for the usual clamps and braze ons to fit.

Special clamp is lighter than clamp and shim, and also prettier.


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## Mark McM (Jun 18, 2005)

*Clamp plus shims*



terzo rene said:


> 35mm is about as big as you can go and still have the front derailleur function properly and for the usual clamps and braze ons to fit.
> 
> Special clamp is lighter than clamp and shim, and also prettier.


Interestingly, the new SRAM X-Generation front derailleur is only made in a 35 mm clamp version, and is delivered with shims to fit 31.8 mm and 28.6 mm seat tubes.

SRAM Front Derailleur


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## sbindra (Oct 18, 2004)

*Braze On vs. Clamp On*

Is there any detriment to using an adapter to convert a braze on FD to a clamp on? I have a braze on Red FD that I was thinking of porting to a new bike. The adapter is $20. I can buy a new Force FD for $60. I was thinking of going with Force anyway because while just a few grams heavier, the Force FD is stiffer than Red (pro teams with Red typically use Force FD for the stiffness).

Does shifting suffer with the adapter?


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## Squidward (Dec 18, 2005)

In theory there is more flex with an adapter in place. In actual use, you won't notice it. These days I tend to buy braze-on FDs and use adapters as I can always use it without an adapter if I move it to a different frame but I cannot do that with a clamp on FD if I'm going to try to use it on a frame with a braze-on mount.


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## cyclust (Sep 8, 2004)

I had one instance where the front derailluer wouldn't go close enough to the seat tube to avoid chain rub while using a brazeon/adapter clamp. I switched to a dedicated clamp on style, and there was enough difference to cure my chain rub problem. So if you have a choice, go with the clamp on derailluer, just keep in mind that if you swap components at a later date, it may mean you have to get a different FD.


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## wankski (Jul 24, 2005)

nope, no problem at all with the adapter.


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## Guest (Sep 25, 2009)

Squidward said:


> In theory there is more flex with an adapter in place. In actual use, you won't notice it. These days I tend to buy braze-on FDs and use adapters as I can always use it without an adapter if I move it to a different frame but I cannot do that with a clamp on FD if I'm going to try to use it on a frame with a braze-on mount.


This is how I look at it as well so I buy braze-on and adapt them as needed.


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## Metaluna (Aug 26, 2005)

TurboTurtle said:


> Shimano does not make all sizes of clamp-on FDs. With some seat tube sizes, the only choice is a clamp adapter and a braze-on derailleur. - TF


I can understand Shimano and Campy not making clamp-on FDs in all sizes, but they won't even make the braze-on adapters in all sizes. Granted you can get a third party clamp for much less, but come on, can't they give steel frame owners (28.6mm) at least *that* much love?


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## Metaluna (Aug 26, 2005)

hobiedog said:


> I'm building up a Klein Q-Pro and was curious why frame makers use braze-on front derailleurs, but require a clamp on them. Why don't they just spec. in, or offer, only clamp-ons? Another way to pose the question, why don't they just braze-on the lug, or leave it off and use a real clamp-on front derailleur?
> 
> Perplexed,
> 
> JT


Why use a braze-on FD? So you can put one of these on your bike .


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## bestT (Jan 29, 2004)

Metaluna said:


> Why use a braze-on FD? So you can put one of these on your bike .


Thanks for posting this link! I was looking for this exact part!!!


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## Squidward (Dec 18, 2005)

cyclust said:


> I had one instance where the front derailluer wouldn't go close enough to the seat tube to avoid chain rub while using a brazeon/adapter clamp. I switched to a dedicated clamp on style, and there was enough difference to cure my chain rub problem.


Let me guess, the seat tube was 35mm in diameter?


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## AJL (Jul 9, 2009)

Good timing for me with this thread. I was trying to figure out what type of FD mount I had. It obviously wasn't a clamp. It looked like it was bolted on. I look up FDs and they are all braze on or clamp, WTH? So now I know it must be an adapter. Thx


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