Front derailleur question

[axel23]

I have an older frame (1985) with a braze-on front derailleur mount. It was designed for a 53 tooth outer chainring and can't be lowered far enough to accommodate a 50 tooth ring.

Solutions? File down the groove? Not sure that would give me the 6mm or so that I need. What about a front derailleur hangar extension? Anyone have any experience with those?

Thx!

[Look585]

6mm is significant, way more than you'd want to file.

IRD and Wickwerks make adapters that might help, but both lower the f.mech more like 10-15mm. I have an IRD in the bin from an abandoned project and will measure if I can find it...

[johnniecakes]

I drilled and tapped a hole above the existing hole in the derailleur body. It was a 6700 series and looked to have enough material. The cage was clamped in a drill press vice and a piece of wood fitted between the sides of the cage so they would not get damaged. A bolt was temporarily inserted into the original mounting hole to serve as an alignment guide prior to drilling. That was about 6 years ago, no problems yet.

[axel23]

I'd be hesitant drilling into a 9100 fd.
Curious to know if anyone has pictures of the adapter solution - allowing the cage to drop lower...

Originally Posted by johnniecakes

I drilled and tapped a hole above the existing hole in the derailleur body. It was a 6700 series and looked to have enough material. The cage was clamped in a drill press vice and a piece of wood fitted between the sides of the cage so they would not get damaged. A bolt was temporarily inserted into the original mounting hole to serve as an alignment guide prior to drilling. That was about 6 years ago, no problems yet.

[Ken Robb]

Grind/cut off braze on mount and use a clamp-on derailer?

[gbcoupe]

https://www.ebay.com/itm/12407373062...8aAmGqEALw_wcB