2016 Trek Speed Concept And Ultegra R8000 FD cable routing issue

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SpecializedColnago
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by SpecializedColnago

Has anybody else had issues with the routing of the front derailuer cable on a speed concept when using the new Ultegra R8000 FD? Specifically my issue is that the pivot point of the cable on the FD places the cable closer to the frame then the old 6800 FD. In my case the cable actually rubs the frame at the top of the cable exit hole. See the pictures below.

Image

Image

by Weenie


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ave
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by ave

Apart from the rub, does it work 100%? On my S5 I can't set the lower stop close enough to the frame, so the chain rubs on the cage.

For your problem I'd put 5-10cm of outer over the cable and be done with it. The pinch would hold it in place. (I take the cable is rubbing on the frame both when on the inner and outer rings?)

CrankAddictsRich
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by CrankAddictsRich

Hmmm... that definitely looks like a problem. I have a TT race this weekend, I'll snoop around and take a look at the guys riding Treks, but I know that a fair bit of them are riding electronic.
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CrankAddictsRich
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by CrankAddictsRich

You might have better luck posting it in the "Let's see your Time Trial Bike" thread....
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SpecializedColnago
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by SpecializedColnago

Yes the cable rubs on both big and small. The cable doesent have a straight path to the new FD so any time the cable is under tension it rubs. I had no issues getting my limits adjusted right and it functions properly with no rubbing. A small piece of housing on the spot is what I had in mind for a temporary solution. I could redo the cables and run full length housing all the way to the FD if need be. I’m just wondering what Trek is doing with their 7 series builds that come from the factory with the R8000 FD installed.

SpecializedColnago
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by SpecializedColnago

CrankAddictsRich wrote:
Wed Mar 28, 2018 11:57 am
Hmmm... that definitely looks like a problem. I have a TT race this weekend, I'll snoop around and take a look at the guys riding Treks, but I know that a fair bit of them are riding electronic.
Thanks Rich! I was running into the same issue trying to find a picture online of my problem, everyone is running Di2 or etap now so it’s a non issue for them. Can’t ask the local trek dealer because they build 1-2 Speed concepts a year and they are always electronic as well.

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jekyll man
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by jekyll man

There's a gromit cum guide that fits in the frame hole.

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SpecializedColnago
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by SpecializedColnago

I actually ordered the same kit when I built the frame. The grommet is in the picture it’s just slid up on the cable so I could show how it is contacting the frame. It does not guide the cable at all it’s just to keep road grime from getting down in the bottom bracket area. The cable is actually sawing through the rubber grommet. I’ve just run a short piece of housing for now until I redo with full length housing.

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jekyll man
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by jekyll man

SpecializedColnago wrote:
Thu Mar 29, 2018 7:43 pm
I actually ordered the same kit when I built the frame. The grommet is in the picture it’s just slid up on the cable so I could show how it is contacting the frame. It does not guide the cable at all it’s just to keep road grime from getting down in the bottom bracket area. The cable is actually sawing through the rubber grommet. I’ve just run a short piece of housing for now until I redo with full length housing.
Ah, i see now.
I had a look at 4 SC's today, 3 (inc an early gen 2) of which were on mechanical, and they all just had that gromit, nothing different unless its new version.

Personally i'd run some outer along that section, or try to space the mech back using 1 of those sram spacers, and hope it moves it enough.
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SpecializedColnago
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by SpecializedColnago

The problem seems to be the new R8000 FD and the fact that the cable enters further forward on the FD. The old long arm FD on the 6800 series would give it a perfect straight line to run because it places the cable further back. I'm going to redo it soon with full length housing all the way to the built in stop on the R8000 FD and I wont have any issues. I am wondering if maybe Trek has a redesigned bottom bracket guide or something that spaces the cable away from the frame a little more for the newly designed FD. I've got it working just fine with a short piece of housing where it was rubbing on the frame.

CrankAddictsRich
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by CrankAddictsRich

Hey... so, I couldn't find anyone at the race with your exact set up.... but I did speak to a guy that is a mechanic at a local Trek shop and showed him your pics. His exact response was, "There’s supposed to be a cable guide to underneath the rear brake that should stop that from happening. Maybe it’s not bolted in properly. I just built one with that exact setup and it is fine. Check the cable guide, check the derailleur hanger."
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SpecializedColnago
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by SpecializedColnago

I’ve got the cable guide installed as it should be. The cable guide is not adjustable in any way so I’m pretty confident that is all done correctly. As for the derailuer hanger the front hanger is molded into the frame so it’s non adjustable and the rear derailuer hanger is brand new and I aligned it when I installed it. Maybe they made a change to the bottom bracket mounted cable guide and I am using the old model or something. Thanks for asking around. I talked to my local Trek shop about it today but they weren’t any help because they haven’t built one with the new FD yet. I’ve got it working with the piece of housing on that edge and I’m going to recable it next week with full length housing for the FD.

by Weenie


CrankAddictsRich
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by CrankAddictsRich

SpecializedColnago wrote:
Tue Apr 03, 2018 2:20 am
Maybe they made a change to the bottom bracket mounted cable guide and I am using the old model or something. Thanks for asking around. I talked to my local Trek shop about it today but they weren’t any help because they haven’t built one with the new FD yet.
It sounds to me like you need to find a different Trek shop. Clearly, something isn't right, they should be able to help you or at the very least contact someone at Trek that can help. Can you take a pic of the cable guide under the bottom bracket, maybe I can show my guy and see what he says. It is possible that maybe there was a change or maybe there were two parts for different models of the frame and the wrong one was included. When I got my DSW Allez, there was a simialr issue. Apparently there were two different cable guides under the bottom bracket, 1 for the normal allez and 1 for the smart weld allez model. The smartweld model had beefier welds between the chain stays and the bottom bracket and there was an extra length of plastic on the cable guide to route the cable around. Apparently, when they were being built as completes in the factory, the builders were grabbing out of the box of pats for the normal allez. I had mine for a few months and the front shifting never felt right. When we investigated, we found that the cable was rubbing and catching on the frame because of the wrong cable guide.
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