clichty

Is there any performance difference between Braze on and Clamp on? I have a 2002ish Klein Quantum with full 105 and I am trying to figure out what my FD is. I have no idea how to tell the difference.

Bike enthusiast

I don't feel any difference.... The clamp on pretty much just weighs more....

A clamp on FD is connected to a clamp which is clamped onto the seat tube...

To adjust the height, you can move the clamping position on the seat tube

A braze-on FD is connected to the frame directly via a small groove that is screwed into the seat tube NOT clamped and can only be adjusted in height by moving the FD along the small groove...

nuovorecord

Do you have a small tab brazed onto the seat tube that the derailleur bolts to? If so, that's a braze on derailleur.

Otherwise, the derailleur clamps onto the seat tube. You should be able to see a very visible clamp that goes entirely around the frame.

Namenda

Performance difference? No, not that I'm aware of. To tell the difference between the two, look at how it is mounted. If it is bolted on to a tab on the frame, its a braze-on. If it has a clamp that goes around the seattube, its a clamp-on.

Bike enthusiast

Here's some pics:

Clamp on:




Braze on:




Braze on FD are on higher end bikes since it's harder to make.....

timmyquest

Braze on FD's are on higher end bikes because they often don't have circular seat tubes...

clichty

Here is my FD.

littledjahn

Well, what do you think?

clichty

I'm going with Braze on

JayC

FWIW, after my BikesDirect fiasco with the slipping derailer, Ive decided all Im going to buy from now on is braze on's with the adapter band. That way if I switch bikes, worst case scenario is I have to buy another band clamp. As it stands now, I had to trash a perfectly good FD to buy a different sized FD for the BikesDirect frame, which promptly slipped down the frame and forced me to buy yet ANOTHER FD on Mike's advice (which didnt solve my problems either) so Ive now bought 3 front derailers when I could have just bought different clamps.

bitterken

Also, some higher-end bike frames come with a frame-specific clamp where you would connect a braze-on FD. You don't see many CF or Ti FD tabs hanging off the seat tube.

bcart1991

lol

It actually looks like you have a braze-on FD with an adapter clamp.

The frame is designed for clamp-on FDs.

I don't notice any difference either.

JMT114

no, there is a clamp going around the seat tube which holds the fd in place. It is a clamp on.

celticfrost

^ +1. Either way, it looks like you don't have a braze on tab on your frame. So if you were ever looking for a replacment FD, you'll need a clamp on.

merlinextraligh

A number of CF bikes come with FD mounting tabs:

e.g.

grahny

It's a braze-on FD, with an adapter clamp. My cross bike is set up this way. If you were to change your FD for any reason, you could get a clamp-on... or another braze-on and reuse that adapter clamp

No performance difference that I'm aware of... it's just the means to how the FD is attached to the frame, and they vary depending on the frame.

bitterken

Any excuse to show off your bike, eh? (I'm just jealous)

grolby

*sigh*

Braze-on front derailers considerably predate non-round seat tubes. It has always been a matter of saving a little bit of weight. I also means that you can design non-round seat tubes without losing the ability to mount a derailer, but that's not why high-end bikes have been equipped with them for so long.

There is a disadvantage to the using a braze-on front derailer, by the way, which is that the limited amount of vertical adjustment means that only a relatively small range of chainring sizes may be used... but that's not an issue most of the time with a high-end road frame.

timmyquest

I'm talking about now-days big guy...
Brazing most often refers to steel, thus the name, and thus the obvious "old" heritage...

clichty

Alright thanks guys, good to know I have an odd setup...guess it gives me an excuse to upgrade

Retro Grouch 

Actually, once you acquire the frame, you pretty much don't have a choice.

If you have a braze-on frame, the braze-on mount will be right where the clamping band has to go on the seat tube so a clamp-on derailleur won't work.

If you have a frame that was designed for a clamp-on derailleur, you won't have any place to bolt a braze-on derailleur onto.

Fortunately, there is an out. A couple of my bikes have front derailleurs in which a braze-on derailleur is actually bolted onto a separate clampong band. Consequently, as long as you have the right diameter clampong band, the derailleur will fit onto any bike.

grolby

Not to get too sidetracked on this, but it's a chicken/egg question. Do modern frames with non-round seat tubes have braze-ons in order to accommodate this change in design, or did the practice of using braze-on derailers (in order to reduce weight) on high-end frames give designers the opportunity to use non-round shapes without paying a functional penalty? There are still plenty of high-end bicycle frames out there - the majority of them, in fact - with round seat tubes. Quite a few of them are even carbon fiber. And a lot of them have braze-on tabs. The point being that it is silly to claim, even "now-days" [sic], that non-round seat tubes are the reason for the continuing use of braze-on front derailers. They're lighter. Oh, and they also allow greater freedom to the frame designer, I suppose.

Pasqually

I have a bottom of the range steel pinarello from 1991 with a braze on.

I have a 1 year old alu colnago with a clamp on.

Make no difference, high end or not.

oilman_15106

The only issue with a braze on set up is that on an older bike with braze on tabs going to a compact crankest can cause some issues with fd alignment and available height or length adjustment.

OP - if you are going to upgrade your frame in the near future go with the idea posted above. Go with a braze on style fd with an adapter clamp sized to your current frame. Then if your new frame has different seattube size all you need to buy is a new clamp of the proper size to use it.

DiabloScott

Your frame uses a braze on type derailleur with the adapter clamp. It's essentially the same as a clamp on derailleur except no one makes an actual clamp-on derailleur band with a diameter large enough for Klein's awesome seat tube.

As mentioned, derailleur braze ons can be a little restrictive in the size of chainrings they'll accomodate, and they don't allow for much rotational adjustment, other than that no performance disadvantage, and the adapter allows for as much adjustment as any other clamp on. Some manufacturers left the braze ons off because they could then report a lower weight for their frames - even though the weight was made up with the component.

You'll enjoy my History of Klein Road Bikes