After searching endlessly on Ebay for a new candidate to retire my front derailleur, I wondered to myself why some front derailleurs had some clamps while others didn’t. I personally thought it was just missing a piece or can easily swap parts around but they’re actually different. On one of the posts on Ebay, somebody had the word “braze” on their item title. Unfamiliar with the term, I decided to use my “googling” skills and see what i get. First on the list as the search results is this thread from bikeforums.net titled Braze-on VS. Clamp-on. Alas, everything makes perfect sense now.

The first reply in the thread after somebody asks the question is:

Braze-on style front derailleurs are made to mount to a metal tab built into the frame. In the case of a classic steel frame, this tab is brazed onto the frame, hence the origin of “braze-on.”

Clamp-on have a metal clamp that wraps around the tube of a frame that doesn’t have a built-in mounting tab for the front derailleur.

Braze-on derailleurs can be mounted to frames that don’t have a mounting tab, using an adapter. The practical advantage of the braze-on style is that it allows the frame manufacturer to make a non-cylindrical seat tube if they want, or use a non-standard diameter at that point on the frame. Some would say it is more aesthetically-pleasing too. The drawback is that it limits the derailleur-positioning options more than a clamp-on derailleur, potentially a problem for those wanting unusually-sized chainrings.

Pretty much self explanatory. Since my bike is older, it uses a clamp-on front derailluer rather than a braze-on. Here are some pictures for references that show the difference between.

One that is brazed on rather than clamped.

One that is clamped on rather than brazed.

Here are more terms with definitions from Sheldon Brown’s website that will help explain further about the alternative way of mounting a front derailleur.

• braze-on – A small fitting permanently attached to a frame. On traditional steel frames these attachments are held on by brazing, but the term “braze-on” is also used for fittings that are welded, glued, riveted or molded onto frames of other materials. Typical braze-ons include cable stops and guides, water bottle cage mounts, shift lever bosses, cantilever brake bosses and cable stops, pump pegs, etc.
• brazing – Brazing is the joining of metal parts by melting a different metal (of lower melting point) which bonds the parts together. Typically, brazing involves joining steel parts with molten brass. Soldering is a similar operation, using lower temperatures and different filler metals (with a lower melting point). In brazing and soldering, the filler metal penetrates inaccessible areas of the joint by capillary action.

In a nutshell, I need to find a front derailleur with a clamp. =P

Until next time…