brommiephillip 

Hey guys,

Ive been modifying my Brompton here in New York City and enjoying some new additions
- Chris King 24mm ThreadFit BB
- Ultegra R8000 (50/34) cranks and 170mm arms
- Stages Left side Power meter for the Ultegra setup
- Speedplay pedal with custom MKS style quick release

Id like to add a Front Derailleur to my setup, so I can use both chain rings, and climb up hills easier with the 34T ring.
My bike is the 6 speed, so i will have 3 deraiullers in the end!

I bought a FD mount and it has the braze-on style mounting but the post is very vertical. Not sure if you guys recommend this cheapy one, or something better.
Others have a more angled post to attach to.

Ill include pics below

I purchased a Force eTap AXS FD and had issues with clearance. The body of the unit is so beefy that the crank arms will hit it, with just 1mm of issue there. I thought maybe to sand it down or etc, but the bike shop advised against it. Then the chain rests on the FD cage and its not long enough or angled, that cage. Another big speed bump.

Is there anyway to do it? Or just get an Ultegra cable style FD which looks longer and thinner, and use a friction shifter, no etap.

Thanks for any advice on the FD setup, friction shifter or the mount.

Phillip
p.s. the Brompton employee who just did the big Lands End tour, installed a FD on same setup as me. And looks like they did a welded on braze-on mount and angled, and used an old school Dura-ace FD, maybe because its thinner and less bulky for the same issues I found (Crank arms catching and folding issues).

brommiephillip 

Www.switchboxcontrol.com/frontderailleur

Please check for pictures here

Jipe

When you say an SRAM Force FD, you mean a Force eTap AXS FD?

brommiephillip 

Yes , its in the pictures if you check the link

Schwinnsta

Search this forum for user member 2_i . He has posted on this topic. He has a triple on his B. He could give a seminar on this topic.

brommiephillip 

Thanks, ill write him. Ill take the seminar

brommiephillip 

Im looking for thinner FDs now like the ultegra one and an old school dura-ace like the brompton employee used on his big ride

Schwinnsta

You can also search for his posts.

brommiephillip 

I tried commenting on some of the threads but unsure about the sram washers that keep getting referenced .. to adjust the angle of the FD

Winfried

Litepro, and Shimano Tiagra 4700 derailleurs are known to work.

brommiephillip 

Thanks winfriend .. the litepro you linked to … is that for the hangar/mount or their deraiuller? I couldnt find it

Winfried

That kit includes the derailleur and the clamp.

In addition, you'll need a double chainring,e g. 50/34T, and a shifter, eg. Sunrace's M90

brommiephillip 

Thanks winfried. Yes I could use your advice and help.

I currently have a shimano ultegra 8000 on their 50-34T and a stages watt meter on the left side arm. I put a Chris king threadfit 24mm bottom
bracket and the setup is very smooth and buttery. Very nice right now.

tried adding the etap setup and it did not work. Too bulky and the crank arms hit the deraiuller body. Also the chain is rubbing against the cage. Both problems.

I see people use very thin deraiullers for this so I appreciate the advice.

here are my pictures so far of my setup

https://www.switchboxcontrol.com/frontderailleur

Fentuz

Carefull, this is a slippery slop; soon this brompton will be fitted with a powermeter

Winfried

There aren't that many clamps available that will fit a Brompton (~38mm diameter), so finding a derailleur that works takes trial and error. It's easier if you work in a bike shop, and have access to hardware cheaply.

IMHO, it's not worth using a high-end derailleur for the Brompton, since the small chainring is only used occasionally.. Even a cheap Litepro does the job.

brommiephillip 

Yes we already made a metal shim for the 40mm FD mounts that are more easy to find. ITs mounted up and in the pictures above.
Watt meter installed also

Here are some links to parts I think needed for a good FD for brompton.

- Litepro FD mount for Birdie LONG LINK HERE
- Sram washer for angle adjutment https://www.performancebike.com/sram...11.000/p309134
- Loctite blue https://www.loctiteproducts.com/en/p...erblue242.html
- Loctite red https://www.loctiteproducts.com/en/p...kerred271.html

- For the FD braze-on.. do any of these seem ok to you guys? I have the R8000 double crank
MODEL -- 105/7000
or
MODEL -- 8000
or
MODEL -- 6800

Also need to tweak the cage for good shifting, two screws for litepro mount around the tube ( Stainless Flat Head Countersunk Hexagon Socket M4x8mm and might need to be filed down), blue loctite in beginning then red might be needed

2_i 

Since I am back to my base, I can correct the screw specification that Litepro uses for securing the mount: Stainless Flat Head Countersunk Hexagon Socket M4x8mm, such as here. The diameter of the head may need to be trimmed with a file or grinder.

brommiephillip 

Thansk 2_i, I updated the post with the correct screw type now.

Cant find the sunrace M90 in USA, a lot in europe but hard to find in the states

Will these shifters be ok? The microshift ones.
LINK

brommiephillip 

Also really quick before i purchase more deraiullers to try.. im already on 3rd one now (sram etap and ultegra 8000 both too big)

This one is the dura ace 9000 - that looks like the same the brompton guy used for the big lands end ride
LINK

This one is the Tiagra 4700, which seems similar design
LINK

Should i get both? or etc? Thanks for any advice as i keep buying stuff that doesnt work

Some pics below of known setups on bromptons

brommiephillip 

Also got this on order, and coming to USA. Will take a while

But the correct FD mount hopefully
LINK

Ill machine a perfect one out of titanium once i see how this all fits together

Schwinnsta

Rivendell usually has them here

2_i 

Are you sure that the particular Ultegra is too big? I look at vendor photos and this derailleur looks slim to me. You do realize that the components were not designed for the particular setting and must be made to work together with the bike by adjustments from all ends, i.e., it is not expected to be a press Enter operation? My own discussion of mounting 105/Ultegra derailleurs can be found in this thread.

brommiephillip 

Ultegra 8000 was just barely too big. Im going to try the Dura Ace 9000, Tiagra 4700 and the litepro mount with sram washer
Some combo of the above will work as the derailleurs are designed with that skinny arm going up and not bulky wide like the other ones.

It is no expected to be a press Enter operation

Here are 4x of the thinnest design derailleurs and less bulky for folding, i could find.
If anyone has installed them, please comment with some feedback, so I can save the time/$$ on some of them

- Ultegra 6700
- Ultegra 6800
- Tiagra 4700
- Dura Ace 9000

Looks like the last two (4700 or 9000) might be the best. The little arm design is pulled back the most, away from seat tube.
Winston member recommended Tiagra above, and 9000 used by the Brompton guy in his LeJog trip

Pics below

brommiephillip 

And just checking if the 4700 or 9000 are ok, then i also need these three parts below?

2_i 

Have you considered pushing the crankset farther out on the drive side? The FD mount you started with, and presumably still use, steals space with its mounting band being in the vicinity of derailleur spring - this is not derailleur's fault.