Can FD-4600 work with entire Ultegra 6800?

[jaibautista]

Hi everyone!

I'll make the formal "introduction" perhaps tomorrow or the day after of my new bike. But before that, I would just like to ask everyone: will there be any issues with me using a Tiagra FD (FD-4600) together with the entire Ultegra 6800 groupset?

Unfortunately, the routing in my steel bike couldn't accommodate FD-6800, hence the mechanic decided to install the Tiagra FD instead. On the workstand, the lever action from the small ring to the big ring feels a bit "forced" but manageable.

Your thoughts?

BTW, here's the bike (Columbus SL frame and fork + "Ultiagra" + CK headset + FR3):



Thanks a lot!!!

[dunbar42]

The cable pull changed from 10sp to 11sp. A double crank FD is basically a 2-way switch so I've heard that it will shift more-or-less fine but it won't trim correctly. There's probably a way to get an 11sp RD on there. Also, you aren't getting the extra leverage of the 11sp RD right now which makes the upshifts feel more seamless.

[F45]

The 11 speed shifter pulls more cable than 10 speed so there's less leverage on the shorter armed tiagra fd than the longer armed 6800. That's probably why it felt harder to shift. I wouldn't worry about it.

You could look into getting a XTR 9000 or XT 8000 side swing fd.

[jaibautista]

Thanks dunbar42 and F45 for the feedback!

Just finished my maiden ride above the new steel bike. And yes, front shifting kind of, erm, sucks. Although the lever throw distance is much shortened, the effort to shift from the small ring to the big ring takes a bit of effort. Not a deal breaker, really, but could be better.

Would you know if FD-4600 (Tiagra) and FD-5600 (105) are the same? I still have a spare FD-5600 with me (from my previous bike); would changing to FD-5600 "lighten" the shift effort?

Thanks!

P.S. Ultegra 6800 is sublime. Coming from a Campagnolo-equipped bike that I've rode for more than two years straight, I am surprised by how fluid the system works. But the highlight of the ride is the steel frame: I can't stop smiling during the ride due to pure exhilaration. It's not stiff as my TCR SLR (and I am getting a bit of brake rub on the front wheel when I stand on the pedals) but the ride is simply superb. Now I understand the sentiment behind the "steel is real" movement.

[dunbar42]

Shimano 10sp road derailleurs should all be interchangeable. I don't know if a triple FD would work with a 6800 shifter though.

[breezerboy]

Out of interest, what makes the frame unsuitable for the 6800 front mech? I haven't found a bike it cannot fit yet, although some have required a non standard cable routing.

Within reason, any double front mech should work (don't use a triple, the shift will be worse on a double) but an 11 speed shimano or 2015 campagnolo will give the best feel with your shifters due to cable pull.

[jaibautista]

@dunbar42

Thanks for the confirmation!

@breezerboy

The FD cable routing on the bike is pretty tight. When FD-6800 was first installed, there was 1mm-1.5mm of clearance between the cable and the rear tire with the FD at the small ring. Since the attachment bolt for the FD-6800 sits far back than its 10-speed counterparts, shifting to the big ring results in the cable hitting the rear tire. When the mechanic tried to spin the cranks, the wheels could just barely move.

Hence, he asked the shop saleslady to find any 10-speed FD. Unfortunately, the only 10-speed FD available was a Toagra FD (FD-4600). Although the shift throw is much shorter than any of the groupsets I've tried over the years (Shimano 105 5600, SRAM Rival, and Campagnolo Chorus 11v (2013)), the shift feel is much harder.

[breezerboy]

The shift throw should be approx the same as you're used to if setup with the correct front derailleur, only with a much lighter action. The reason yours has shorter lever throw and firmer feel is because of the cable pull mismatch, think road/canti brake being pulled by V-brake lever.

If you have to use a 10 speed front mech due to tyre clearance issues you may find the only way to improve things is a bit of improvisation. If possible, try to extend the lever arm on the front mech while retaining clearance. Something along the lines of the hubbub conversion used on rear mechs may be a good starting point. I suspect due to the frame design (chainstays a bit too short) you may never get the true light action feel of the 11 speed front mech, but a bit of ingenuity could certainly improve things.

[Svetty]

The only way you'll get a decent front shift is to alter the cable:pull ratio to suit the mech. If it really won't accommodate the 6800 front mech you might find the best option is to use a left shifter from the 4600/5700/6700/7900 family. Won't look quite right having odd shifters but it will at least work OK....

Shame the frame is quite so tight in the rear triangle.....

[F45]

[HTML]

You need to pull the cable away from the tyre somehow. This idea may or may not work but it could be worth a try. What about modifying a front derailleur braze-on clamp adapter and clamp it to the bottom (or near) of the seat tube. Turn it into a kind of hook that re-positions and pulls the cable away from the tyre.

You could use a thin nylon tube over the cable on the hook area where the cable would rest. to lessen any extra friction.


Edit: maybe a top pull cable adapter could work ? based on the idea above.



or a clamp on cable guide of some kind.

[Raineman]

I think it would work if you could shim the FD away from the frame to create the extra space. If you have a band on mech then you could just use a larger size plus a shim on the drive side to help push it out further.

[jaibautista]

Thanks everyone for the additional feedback!

I think putting a clamp on the seat tubs is out of the picture, as the clearance between the rear tire and the seat tube is very minimal. Hence, the main challenge for me, outside of having the frame re-worked (i.e., chopping the rear triangle to make way for long seatstays and chainstays), is to push the FD pinch bold forward. I've already spoken with the frame builder and he's asked me to bring the frame to him. I just hope the resolution doesn't involve reworking the frame.

After riding the bike yesterday, I don't see myself riding my TCR SLR anymore, unless it involves a whole lot of climbing. Steel is real, indeed!

[jaibautista]

Hi everyone! Just a quick update on my "issue" with the FD and frame.

I brought my frame to the framebuilder this morning. Initially, we thought of drilling a hole on the right chainstay for the cable to pass through to accommodate the Ultegra 11-speed FD. To demonstrate the "problematic" FD cable routing, I had to remove the Tiagra FD and install the Ultegra FD. Good thing he decided to get his road bike and have his own rear wheel installed in my frame. Lo and behold, my frame could accommodate the Ultegra FD! We concluded that my wheelset was causing the FD cable rubbing in the first place; while it was true, it was aligned a bit to the right.

So I brought my rear wheelset to my trusted bike shop and had it aligned. Now, all is well.

Again, to those who suggested potential solutions to my initial query, thank you very much!

Now, I can ride my bike with a full 11-speed Ultegra. Thanks again WW!

[Svetty]

Glad you got it sorted.