Ultegra 6800 Braze-on Front Derailleur - How to actually set it up?

SNS1938 · Jun 12, 2014

I upgraded to 6800. I did not realize the front derailleur has changed so much. There are these little metal shims which you put on the frame and then adjust a grub screw against to move the derailleur.

Ive googled and watched a shimano video on youtube, but I'm still confused. Add to that, my bike doesnt really seem to have a suitable surface to put the shims on.

I have also looked at the dealer guide on installing it.

1) Can it be installed without the adjusting the grub screw and using the shims?
2) Anyone know of any more info I can look at to help me out with this?

Thanks

cxwrench · Jun 12, 2014

Why would you bother to install the shim if you weren't going to adjust the screw? That doesn't make any sense at all.
Have you turned the screw in to see where the shim needs to be? On some bikes it will hit the braze-on mount and you don't need the shim. Between the flat shim, the bent one, and maybe a hammer, you should be able to get it to work on just about any frame.
I know Shimano wouldn't have included the screw if it really wasn't needed, but I've seen a ton of bikes that got built w/o that screw every being touch. I'm sure the shifting is better w/ it properly adjusted, but the derailleur will generally work w/o it.

I turn the screw in to see where it will contact the frame, then back it out a few turns and put the shim in place w/ needle-nose pliers and then turn the screw in while I'm holding the shim in the right spot.

mannymerc · Jun 12, 2014

I had it both ways, without the plate and the screw adjusted to the lil plate, it worked better for me, but it did work without it.

SNS1938 · Jun 12, 2014

The frame has an angled cutout where the screw contacts. It's very angled. I'll photograph tonight.

I hadn't used the screw, but also didn't have the tool to tell me how to route the cable, so I'm not sure why I couldn't get it to work.

Pictures would help explain this better.

mannymerc · Jun 12, 2014

like I said, it will work without that set screw touching the frame, but if there any way possible for you to custom make something to make it work do it, I mean, thats what I would do.

SNS1938 · Jun 12, 2014

What does the screw actually do? From YouTube, it looks like it does the same job as the lower limit screw?

It is looking like my issue with why I couldn't get the derailleur to work well, is because I don't have the cable routing tool. I've ordered it from LBS, but they then said it'll be a couple of weeks.

Will my old DA7800 front derailleur work with a 6800 shifter? I'm not sure if they changed the pull ratio or not for 6800.

Thanks.

goodboyr · Jun 12, 2014

It provides support once properly adjusted to the reaction force generated by the FD action. In other words it stiffens the FD against movement so you get cleaner shifts from small to big ring.

SNS1938 · Jun 12, 2014

Thanks. I'll photograph tonight, but essentially the frame has a cut out in the tube where it goes in on an angle at that spot, making it difficult to use a shim. The frame is a coupe of years older than the derailleur.

Hopefully I can get it working sufficiently well tonight.

goodboyr · Jun 13, 2014

I had a similar issue doing a 7970 install on a look 595. Ended up building up a spot on the frame using jb weld topped by the aluminum plate.

SNS1938 · Jun 13, 2014

I have managed to get the plate in place, but I'm still having no luck. Finally though, I think I'm onto why. The ''converter bolt'' that came in the derailleur is broken! It's only plastic too. It was an OEM FD6800, so possibly the manufacturer that it was made for didnt need a converter bolt?

Not a great experience so far, as the cranks were missing the large axle nut/bolt too.

Without the converter (or the tool to tell me if I need the converter), I don't get sufficient travel to move the chain to the big ring.

SNS1938 · Jun 13, 2014

View attachment 296686

SNS1938 · Jun 13, 2014

okay, getting more understanding. The ''converter bolt'' that came with my derailleur was plastic. I am not sure if it is 'broken' or if the snapped plastic post on it was intentional as it was OEM and may not be required for the frame it was packaged for.

I have found that the actual shimano converter bolt is metal. So by not having the converter bolt, I don't seem to get the correct leverage ratio and pull on the front derailleur.

I originally thought the lack of support bolt use was the issue, but I think the broken converter is the issue.

View attachment 296687

wim · Jun 13, 2014

SNS1938 said:
I originally thought the lack of support bolt use was the issue, but I think the broken converter is the issue.

Agree. My response above was based on the fact that in certain cases, the converter will work for you in both the ON and OFF position, meaning that you really don't need it for the derailleur to function. But the pin does provide a place for the cable to rest on, so you do want a similar cable rest there if possible.

On page 14 of the .pdf file accessible at the link below, you'll see a chart about the FD-6800 converter ON and converter OFF cable routing. It might give you some ideas about a temporary fix. Under FD-6800, click on DM FD0002-04:

SHIMANO Dealer's Manual / User's Manual

Here is the exploded of the FD-6800 with the item numbers and parts numbers of the FD-6800. The converter is item 3, so it should be available as a spare part.

https://www.paul-lange.de/tradepro/shop/artikel/docs/Explosionszeichnungen/SHIMANO/FD-6800-3604A.pdf

wim · Jun 13, 2014

Try hooking up the cable with the broken converter in place. If that doesn't work, take the broken converter out and see if you can hook up the cable without it. It may just work fine. But this has nothing to do with the grub screw that pushes against the frame to stabilize a basically cantilevered braze-on derailleur.

SNS1938 · Jun 14, 2014

Thanks. I've found that the converter should be metal, and not the plastic one I have. I'll order one off an ebay seller, which is about $5 delivered.

I've got the plate in, but its not brilliant, and do have the the derailleur shifting. So it's working, but I feel it could work better with the converter in.

wim · Jun 14, 2014

SNS1938 said:
So it's working, but I feel it could work better with the converter in.

It might well do that. The converter allows you to precisely set cable pull in accordance with cable entry angle. Get the TL-FD68 gauge while you're at it to determine if the converter needs to be in he ON or OFF position.

Ultegra 6800 Braze-on Front Derailleur - How to actually set it up?

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