[SpokaneSteve]

Hello all:

I am puzzled as to why a derailer hanger integrated into the seatube isn't standard on higher-end bikes. For example on my 20 year old Trek 1500 aluminum there is a "braze-on" style front derailer hanger but on my new Supersix I have to use a clamp-on. Any ideas?

Thanks, Steve.

 

[mendo]

You have more adjustability with a clamp-on, so it's preferable in that way.

 

[Camilo]

Also simplifies the manufacturing of the frame and eliminates one part that has to be "just so", avoiding potential errors. If there's no advantage to it (which can be argued), and the tube is round and standard size, why complicate the manufacturing and therefore potential error?

I am currently using my first ever braze-on derailleur bracket, because my new carbon frame has odd shaped seat tube and a clamp wouldn't work. I'd have to say, I would prefer clamp on, but it's not a deal breaker either way.

 

[Richard]

Plus many older frames with a brazed/glued/riveted front derailleur "attachment" won't allow the derailleur to be positioned low enough to work well with a 50 tooth compact crank.

All three of my currently in use front derailleurs are "braze-on", by the way, and only one frame has a braze-on fixture. If I want to move one to a different frame with a different seat tube diameter, all I have to get is the appropriate adapter.

 

[Kerry Irons]

Key point

I am puzzled as to why a derailer hanger integrated into the seatube isn't standard on higher-end bikes.

Saves weight. And we all know how many buying decisions are made over 30 grams! Just like why we have seat post collars instead of an integrated clamp, or bolt-on BB cable guides instead of one built onto the frame.

 

[frpax]

Would compact cranks have anything to do with this?

 

[brblue]

One of my riding buddies actually broke a steel frame below the FD collar (not sure if the FD clamp has anything to do with it) . Plus, couldn't overtightening the clamp/crimping the tube be an issue with thin wall tubes? Anyway, though the braze-on is less convenient from a setup/compatibility point of view, imo it gives a cleaner look to the frame.. And as above posters stated, it allows for all sorts of strange (aero) seat tube shapes

Edit: After re-reading my post I'm not sure what my point was I'd also expect braze-on on higher grade frames. But im really curious if clamp-on can ruin the seat tube..

 

[smoo]

Doesn't bother me at all which method is used. The weight saved in the frame by doing away with the braze-on attachment is gained again in the clamp itself of course. Just make sure the clamp bolt is tightened to the correct torque and it's fine.

There is one thing that is bugging me at the moment about clamp-on though. I am moving from a frame that needs a 32mm clamp to one that is 35mm, and it looks like I can't actually swap the clamp on my record derailleur. I will need to sell the current one and buy a new one at a loss. With braze-on that wouldn't have been an issue.

 

[DaveT]

A frame with no braze on tabs makes it easier to select and/or change your derailleur, and makes it far easier if your choice of cranks is compact. Some frames with the der tabs won't allow enough derailleur adjustment and prohibit the use of a compact crank.

I personally don't care either way but if I'm looking at a new (to me) frame built with a derailleur tab, I have to make darn sure that it will have the range of adjustment I need whether I use a standard or compact crankset.

 

[Fai Mao]

And because what happens if Shimano decides to come out with a ShIDTS (SHimano Integrated Derailleur Tabbing System) that will only accept a Dura Ace front derailleur that will not shift with any shifter except a model 8100AXO-b Front derailleur and an 8100MXD STI shifter?

A clamp is a better idea

 

[wim]

I am puzzled as to why a derailer hanger integrated into the seatube isn't standard on higher-end bikes.

Part of the answer is the fact that "integrated into the seatube" would often take the form of "riveted or screwed to the seat tube." That means drilling two holes into the seat tube, which on high-end frames is generally thin-walled to save weight. Personally, I would prefer a clamp to two rivets or screw fittings popped into two holes.

 

[Richard]

There is one thing that is bugging me at the moment about clamp-on though. I am moving from a frame that needs a 32mm clamp to one that is 35mm, and it looks like I can't actually swap the clamp on my record derailleur. I will need to sell the current one and buy a new one at a loss. With braze-on that wouldn't have been an issue.

My point exactly.

If I ever want/need to move this lovely Record front derailleur from a 28.6 seat tube to a 31.8 or a 34.9, all I need is a new $12 clamp-on adapter.

 

[Richard]

Oh, and if it ever came to pass that it was going to a frame with an "integrated" hanger, I'm golden. Also. Too!

 

[EverydayRide]

Hello all:

I am puzzled as to why a derailer hanger integrated into the seatube isn't standard on higher-end bikes. For example on my 20 year old Trek 1500 aluminum there is a "braze-on" style front derailer hanger but on my new Supersix I have to use a clamp-on. Any ideas?

Thanks, Steve.

Very interesting read on this subject here. I, too have a Super Six [2008]. There are some points given in the article which clarify some instances where by not having a braze-on is beneficial, but the main point -through what I've seen- would be frame integrity. Read the article and decide for yourself.