Bicycle Mechanics - Braze-On vs. Clamp On

What are the benefits of a braze-on front derailler attachment compared with a clamp-on type hanger? I notice that many manufacturers are now using the clamp type attachments. Are they as good or just cheaper or is it easier to adjust for more types of group sets?

I always thought that a braze on was better, because you replaced the clamp with a little strip of metal, saving a few grams. Plus, it always struck me as a cleaner, more elegant solution. The down side is that if it isn't right for your cranks and derailleur, well, it's welded on. I had a friend who had a heck of a time getting his front derailleur right. The shop eventually wound up filing down the grooves to give him a little more adjustment room, and it still wasn't quite right.

I think clamp-ons are more popular with manufacturers for the one-size-fits-all reason... it makes it so they don't have to worry about getting the tab right. Consequently, that's what they pushing in the marketplace.

In the worst case, a braze-on hanger can cause heat damage to thin-walled tubing and the mechanical stress of gear changing can cause the tube to crack.

Braze on saves a few grams of weight.

Clamp on has greater versatility to for using various sizes of chainwheels.

Sheldon Brown says front der braze ons are "the devil's work."

Dave

From a shop standpoint, I like braze on der. I can stock one der. and three braze on style clamps in different sizes. Helps reduce inventory as their are, road and mountian, about 80 different front der. combos, with clamp sizes, top pull bottom pull, compact, models, etc.

my braze-on has a crack running down the middle from the top to the hole.... my derailleur is hanging on fine, but it could very well break off and need repair sometime in the future..

What's a braze-on front derailleur? I thought they went out with the Simplex suicide shifter on the 1960 Varsinentals! :)

Actually, all 5 of my bikes have clamp-on front derailleurs, and the only time this ever proved problematic was when the clamp of one of my favorite SunTour cyclones snapped.

Delerious(five), you could, if it fails, cut and file off you old tab and use a braze on style clamp or have a frame builder braze on a new tab.
John E, are you talking about the reverse sprung Simplex with the bakalite clamp or the real suicide, reach down there and shift the big lever, deal? A lot of new bikes come with "braze on" tabs for the der. I think it helps keep the built weight down.

I can see a advantage to bicycle manufactures, they don't have to worry about following a standard on seattube size or shape. If they want to ovalize the tube it is not a problem, or make it a non-standard size. Just put a braze-on and it's no problem.

I think that braze on would be lighter but only by maybe 4 or 5 grams at the very most. So the real benefit would be the inventory reduction, but you lose the benefit of being able to move the der up or down depending on your chainwheel, so it's a wash. Personally I like the clamp on look because it kind of makes the bike look like an older classic type of bike where they used clamps for der, brake cables etc. My front der is a Suntour Superbe with the clamp on style.

Please note; I said I prefer the look of the clamp style, I do not think one is better than the other.

Both types work equally well in most situations. The drawbacks and benefits have been well defined above. I have only had one problem with the braze on type setup in my years as a mechanic. It was on a Bianchi road frame that was a couple of years old. The mount cracked and half of it broke off rendering the braze on mount useless. Called Bianchi and 5 days later had a new frame and fork ready to build for the customer under warranty. Amazing customer service as always.

-Ryan

I run a braze on front der with an adapter so it clamps to the frame. The reason is because I may be switching frames eventually and not matter what I get I'll only have to replace that clamp on adapter. As a mechanic I also find it easier to adjust the braze on frnt der more precisely ( sometimes when you lossen a clamp on one and retighten it, it will shift slightly as it is retightened)

Braze-on saves a few grams of weight? A few grams? Shaving that morning saves more weight that a braze-on connector. The concept is inflexible and bogus.

Irregular seat tubes.

braze-on and clamp-on are really 6 of one and a half dozen of the other in most cases. Braze-on offers a cleaner look, and saves a few grams, clamp-on is usually more versatile.

But there are situations where Braze-on (we should start calling them attached mount given that they're screwed, glued or pop riveted on half the time these days) has clear advantages. One of these is on ultra steep seat tubes. This often would put a clamped on FD too far forward with respect to the chainrings, making for degraded shifting. With an attached mount the frame builder can push the mount back a bit, and correct the angle to ensure the FD works optimally.

Conversely, Clamp-on FDs allow greater freedom of height adjustment and are better for those who use uncommon chainring sizes, or want the freedom to switch from 53t to compact chainrings.

I some designs like Bike Friday is not a conventional seat tube ,
so the FD is mounted to a Braze on to orient it in the appropriate relation ship
to the chainring.

a custom piece that has a braze on tab on it is used to put a front shifter & 2 ringcrank on a Brompton,
on those the seat tube passes behind the BB entirely.
the tab sits at an angle. to compensate.

just cannot get MTB FD in a braze on fitting type

Antique thread.

Antique thread.

I'm impressed at how old this thread is. I mean, it doens't even have a posting from Sheldon Brown it's so old.

So? :notamused:

my kestrel doesnt have a true round tube on it thus making the braze on the only answer. Apparently kestrel didnt expect too many people to run a 53 up front. I can use it but the hieght adjustment is completely maxed out.
195841

8 years is pretty impressive!

I like clamp front derailers just a teeny tiny bit more than brazeons. No particular reason that I can think of.

It would be tough to tear my Pinarello with braze-on FD out of my hands, however.

Braze-on saves a few grams of weight? A few grams? Shaving that morning saves more weight that a braze-on connector. The concept is inflexible and bogus.

If, in a race, all other things are exactly equal, then by simple math alone, the bike with the braze-ons will win out, over the one with clamps. And, that is an inflexible mathematical actuality, not a bogus opinion - in my opinion, of course.

That said, it was not the weight saving factor that lead to the popularity of braze-ons. Simply put, braze-ons save manufacturing and assembly costs, at the manufacturer's level. They do little to improve ride quality, or do they?

Look at today's streamlined bikes. Every effort is being made to reduce wind drag. It this also an inflexible and bogus concern? Not in my book. It is just one more little step in refining the nature of the bicycle. Again, my opinion.

So, if we add up all of the little weight saving ideas, that have come along over the years, you get today's bicycle. A fourteen or fifteen pound, plastic and metal wonder that kicks ass, when compared to anything from the 20+ pound clamp on era days.

Again, my opinion.

Braze-on/glue-on front derailleur mounts became popular when frames started appearing with non-standard seat tube dimensions. There is really no compelling reason to use them in any other situation.

A front derailleur mount that is permanently attached to the frame restricts you in the choice of chainrings (size & number) in a way a clamp on front derailleur does not.

Wondering what possessed CicWy, as his first post, to throw out a random comment on a thread dead for 8 years?

I think unless you are talking about steel frames, the braze on FD is a thing of the past, almost. I love the looks of a braze on FD though, clean, no metal clamp ruining the paint under it, etc.