scale

I am upgrading an older road bike and going with either 105 or Tiagra. Most of the 9+ speed front derailleur stuff is braze on mount that i am finding. I think i even have one around here somewhere.

How do those adapters work? Are they ok? I am thinking of getting a clamp-on to braze on adapter and run that vs trying to find a 28.6 front derailleur. Partially because i think i already have a 105 braze on somewhere around here that i can use if the adapters are fine

bikemig 

either is fine

scale

Thanks. I was just curious if there were any issues with the clamp on style adapters before i purchased one.

bikemig 

I'm running one right now, no issues for a modern shimano claris FD that is running on a 28.6 steel bike.

Braze on FDs are a proven design as well and there are appropriately sized clamps for those.

Andy_K 

I'm using use braze on adapters on several bikes. I prefer them to shims, but functionally either is fine.



One advantage of a braze-on adapter with a slot rather than a hole for the screw as pictured above is that it lets you adjust the derailleur height without sliding the band up and down your paint.

I think Shimano braze-on front derailleurs come with a concave washer and so expect a convex surface on the adapter. This allows a bit of rotation without moving the clamp as well. Some adapters have a flat front surface and so you'd need a different washer (which is easy enough) and you'd need to rotate the adapter clamp to align the derailleur horizontally. That's no different from a derailleur with a built-in clamp though. Here's a pic of an adapter set up that way (which also required a shim).

denny1969

The Shimano FD-5700 is also available in a clamp on model that uses a rubber spacer to make it compatible with a 28.6 mm tubeset. I have the unit on my 1985 Schwinn Tempo.



Dennis

RandolphCarter

I have a 1986 Trek with a 105 (5800) groupset on it.

I used a clamp on adapter like the first pic in Andy K's post. It and the front derailleur have worked perfectly, no issues.
Since is used the 105 brifters, I also bought Shimano cable stops and mounted them where the old friction shift levers used to be. They've had zero issues also.

scale

perfect. I will pick one up. I did have a front mech here.....it took some digging but i found it Thanks all