dnomel

I have a few questions about this shimano 105 front derailer that I found and thought would work with a braze on tab.

https://www.flickr.com/photos/6978561...n/photostream/

First, is the cable supposed to go around and over that little tab sticking out to the left of the cable clamp bolt, and then bend sharply and exit horizontaly out to the right?

Also, in a couple of the pictures you can see that I stuck a small washer between the derailer and the braze on tab mount. This was because without it, the back of the derailer hit the head of the lower screw attaching the braze on tab to the frame, and cocked the derailer out at too much of an angle.
I also used a brake bridge washer between the head of the screw that attaches the derailer to the braze on mount, because without it, when I tightened that screw it threw off the alignment of the derailer.
This is the first braze on mount I've had, and the derailer did have a clamp attached with the same screw, no washers, so I'm not sure what's normal, or if I was missing some parts or something. This is on a cannondale.
It seems to work ok as pictured.
Thanks for any ideas.

Zef

Yes, route the cable over the tab. Also, look for a small groove on the arm of the derailleur to seat the cable against. In the first picture it looks like the groove is present but the cable is not seated against it. Not all derailleurs have the groove I am talking about but it seems from the pic that yours has one. The tab is to increase the mechanical efficiency of the derailleur.

Normally there is a concave washer between the derailleur anchor bolt and the right side of the braze-on tab. It looks like you made a suitable substitute out of the brake bridge washer/spacer.

As long as the derailleur is attached to the frame and maintains correct alignment then you did well. If you are concerned about having the correct parts then you could check your LBS if they have the correct washers in a drawer or can order them for you. But if it were me and the bike shifted correctly once set up and the derailleur maintained position then I would call it good and just ride the thing.

Good job on getting it to work.

-j

HillRider

+1 It is important to route the cable over and outside of that tab and then through the groove above the clamping bolt if the indexing is to work properly.

dnomel

Thanks. There does appear to be a little groove there, it just seemed like it would have put a kink in the cable and I'm used to readjusting that length. Next time I fiddle with it I may try putting the cable over that tab and see if I notice a difference. One other thing, the braze on tab didn't seem magnetic, just wondering if it's likely titanium and if that's common.

HillRider

It's most likely aluminum.