Merckx. Corsa Brazeon too high for a 34-50 cranket

[Web1111a]

My Merckx Corsa Extra has a Centuar Square Taper 34-50 .

The front derailleur is a Record silver front derailleur . It struggles with getting on the big ring. The frame is I believe circa 1990 Molteni reissue.

Are there other front derailleurs that may get lower? I have a Chorus CT and a Mirage braze on. I also have a silver 10 speed Centaur and a Silver Athena 11 on a 32 mm clamp. Also I have a 9 speed silver Chorus braze on.

I see FSA and wick works have an extender. Is there any that anyone has experience with that works with 34-50 fsa gives impression for 48 or smaller

Thanks

[jamesdak]

I'd contact Chris at Wickwerks directly and ask. He tests the crap out of his stuff so I'd expect he'd know without a doubt if his product would work for you.

If you can share some pics of how things are set up now maybe folks will have other suggestions for you. I know in some cases it works to elongate the slot in the FD Braze-On.

I'm assuming you have a big gap between the FD and the chainring...

[benb]

If the bike predates the compact era are you sure you can't set it up with rings appropriate for it and then just get your lower gears at the back since much lower gears are available on the back of bikes now?

[Mark McM]

If your bike uses a braze-on front derailleur, I'm not sure why you are mentioning clamp-on derailleurs. Unless the seat tube is round, then you might be able to install a clamp-on derailleur below the braze-on tab. But in that case, the derailleur tab might get in the way and the derailleur might end up not being able to be mounted high enough.

In any case, CT derailleurs do extend a bit lower than standard derailleurs, being designed to work with compact chainrings, so you might want to give that shot.

The FSA and WickWerks adapters can lower the derailleur, but they also offset the derailleur rearward a few millimeters (due the thickness of the adapter), so that might interfere with alignment a bit. IRD also makes a sub-compact front derailleur adapter which doesn't offset the derailleur backward (the adapter is mounted in front of the tab, rather than behind). But unlike the FSA and WickWerks adapters, the IRD has a minimum amount of drop built into the adapter (about 6mm or so). So if you need to drop the derailleur by 1-5mm, but a 6mm drop would be too low, then the IRD adapter won't work for you.

[zzy]

SRAM 10 front mechs have two holes for different heights on brazeon tabs. I find they always work with compact cranks and older steel frames.

[thwart]

Then there’s always the rat tail file approach…

[dana_e]

it would be to high for the little ring, big ring should be in range. IMO.

[buddybikes]

https://www.tradeinn.com/bikeinn/en/...B&gclsrc=aw.ds

[Web1111a]

I mentioned the clamp on ones because I am under the impression that some of them can be removed from clamp and used as a braze on

Originally Posted by Mark McM

If your bike uses a braze-on front derailleur, I'm not sure why you are mentioning clamp-on derailleurs. Unless the seat tube is round, then you might be able to install a clamp-on derailleur below the braze-on tab. But in that case, the derailleur tab might get in the way and the derailleur might end up not being able to be mounted high enough.

In any case, CT derailleurs do extend a bit lower than standard derailleurs, being designed to work with compact chainrings, so you might want to give that shot.

The FSA and WickWerks adapters can lower the derailleur, but they also offset the derailleur rearward a few millimeters (due the thickness of the adapter), so that might interfere with alignment a bit. IRD also makes a sub-compact front derailleur adapter which doesn't offset the derailleur backward (the adapter is mounted in front of the tab, rather than behind). But unlike the FSA and WickWerks adapters, the IRD has a minimum amount of drop built into the adapter (about 6mm or so). So if you need to drop the derailleur by 1-5mm, but a 6mm drop would be too low, then the IRD adapter won't work for you.

[Nomadmax]

Before you do anything else, mount a compact FD as low as it'll go and try it. Sometimes cage height isn't as important as you think. Just make sure the H limit screw is adjusted properly.

[johnniecakes]

I had a similar problem on a Concorde frame about 2 years ago. It was solved by drilling and taping a new threaded hole in the derailleur itself. There was about 18mm of space above the existing mounting hole so a new hole was placed centered in that area and it lowered the front derailleur about 9mm. Before you try and drill in a curved surface take the edge of a file and put a small flat on the mounting tab of the derailleur so there is a flat area to center punch.

[chrisroph]

file or dremel, EZ

[Wolfman]

I have the Wickwerks extender at home... mounted, but never ridden... I'd let it go for a super deal since it might be exactly what you need... PM me if interested.