brommiephillip 

Yes that deraiuller mount really sucks. Its too far forward. All of you guys are able to mount your FDs farther back and behind the seat tube, with a good angle.
Ill attach some of the pics Ive found of yours and mounts people have used correctly.

If there is anyway I can get some measurements from you guys on the FD mount, I can make a custom one from titanium and provide it back to the community once its milled.

My litepro is coming in one month from aliexpress, but until then I could work on designs for a Brompton specific one.. if you guys can help me draw it up.

brommiephillip 

Any one have any comments on these 4 FD types?
- Ultegra 6700
- Ultegra 6800
- Tiagra 4700
- Dura Ace 9000

I thought the last two were the best but anyone using the first two?

2_i 

The primary problem is with that crummy adapter. On my side, most of my derailleurs are triple. However, I have a double 105 (model No. not avaialable at this point) and it mounts fine onto that crummy adapter. Within triples, I fail to mount Ultegra 6703, but Tiagra R443 fits fine, if this were of any help. When I use my own adapter instead, Ultegra 6703 mounts fine, but does not work well with my chainring set, which is an entirely separate issue.

brommiephillip 

Hey guys, need your help. I got the favored FD mount from Litepro and it arrived from China/aliexpress today.
Also was able to get deraiuller #3 above... the dura ace 9000, which I saw mounted on the LandsEnd bike in the pics above.
Received the sram washer for angle also.

Brought everything to my mechanic and he tried it and showed these pics below.

He said it hits the crank arm and still not able to work. Also the diameter was too big for brompton and needs shims.
And other problems with angle and down shifting.

Is there a trick thats being overlooked?
Do I need to bring it somewhere that will do custom work for me or design a FD mount from scratch?

Please post any pics of your FD mount if you have the litepro, just so we can see
Thanks



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2_i 

You need to push the crank out to the drive side. When using a square taper bracket and crank, this is trivial. You just put a spacer which could be one from a cassette. (Trials, at some level can be done even without a spacer - you just screw out the cartridge/cup a bit out.) I have no experience with the outside bearings, but Chris King sells some fit kits, that could include identical spacers. The shim for the adapter is trivial too - just a strip from a tube. If you want to be fancy, you cut one from an alu sheet. There is some bolt there that seems to interfere with the adapter - do not know what that is.

Quite honestly, if just those above are problems for which the skills of the mechanic and yourself are not sufficient, I do not see how this project can converge in a reasonable time.

brommiephillip 

Thanks for replying Pawel, shimming and BB spacers are pretty the basic.

The project can converge as you said, and thanks for the feedback. We have a fit kit from CK already on there but the mechanic said he had run out of room kicking it out to the drive side

We’ll try again

2_i 

When you use the original square taper BB, or similar, you can retain the original left crank, that uses space very economically and can be brought by quite some distance to the frame with impunity.

brommiephillip 

For my project we use an ultegra r8000 crank and stages left arm with power meter. The Chris king BB was spec’d for this setup

2_i 

Still, I am a bit baffled by the situation. On my triple setup I can measure about 25mm gap between the inner side of the right crank and the top part of the derailleur and also a Q factor of about 160mm. If I were to correct these values for the ring spacing when going down from triple to double crankset, by about 8mm, this would yield a 17mm gap and 152mm Q factor. Now the Q factor of the particular Ultegra crankset you are using is 146mm, from on-line specs. Dividing 152-146=6mm by 2, this could explain a drop in the gap of 3mm, but not the gap between the driveside crank and top part of the derailleur turning to negative values! Spacers, on their own, can help changing extension to left or right by a few mm but not centimeters. Something is grossly off here, in which the spacers will not help. Is the power meter taking so much space on the left hand side that it will be never possible to have enough space on the right for the derailleur? If this were the case, the project would need to be abandoned, at least in the current form.