That sucks. I’d echo the post above and suggest trying the cross method if you’ve been running cables same side. If already running cross, maybe try same side just to change the angles a little. This might also help confirm what entry/exit point is causing the issue.
Have you tried a couple different shift cables to make sure you didn’t get a bad cable with a fray at some point hanging things up?
If you had not tested the shifter, I’d be highly suspect of that being the problem based on the description of the issue.
Last ditch solution - Merlin is running a decent deal on DI2 right now for the upgrade kit. Never monkey with shift cables again.
The key red flag has been a brand new cable catches when running through the entry port even without any other components involved, no mech, no shifter. This is why I went to nosed ferrules but guessing the cable tension still makes it an issue.
I didn’t mention above but tried swapping sides on the routing and the same side entry point had the same issue - i.e. problem moved to front mech cable.
Now back to straight as crossing over cables does make routing nicer but then you also cross the cables internally, and was trying to avoid that.
Thought had posted that above but with the time this has dragged on for I have lost track.
I did again replace cables after switching back to same side, fully flushed out liners and lubed inners with light machine oil.
So recap:
New outers, new cables (twice)
Nice routing, no kinks or twists
Clean cables with a little light machine oil
Tried routing the same side and crossing over
Always the cable through the right side entry port that sticks
Tested rear mech and shifter off and on bike
Latest time building used nosed ferrules to guide cables into downtube and avoid suspected notched hole.
Options appear to be:
Drill out holes slightly to clear, try to remove any suspect damaged material. Not been able to get a good look inside though, am going by shape of hole when shine light down.
Di2 - had been eyeing up the Merlin kit but my trainer has self destructed and my work Cycle2Work scheme (Halfords one) is pretty limited and only place I can find to use it to buy Di2 is more expensive than Merlin even with the tax break!
New bike - any excuse… Again no funds.
So for now I am riding my cheap thrown together CAAD8 and enjoying the total lack of faff.
Please follow up once you have the opportunity to borescope the internals. As a CAAD12 owner I’m curious to know the issue and resolution. I am also surprised that no one else seems to have had this issue. Is it possible that your frame has a defect? Also, you did mention that you had teflon you had to remove. Is it possible that there is “debris” causing the hangup?
It is possible this is a defective or out of spec frame for sure. It could easily be the casting around the inserts (which I assume are welded in) is poor, but I would be surprised.
The route is certainly clear inside, I’ve run pipe cleaners through and you can see clear daylight (photo is above).
I’ll try to get the borescope later and get a screen grab if it’s worth it
I can’t get an answer from the store I bought it but a contact who works elsewhere and supplies Cannondale has said it should be put forward for a warranty claim.
The cable angle is dictated by the straight run to the guide below the BB, he agrees with me it’s not good form for the cable to turn that sharply through aluminium and potentially that port has been incorrectly welded / spec’d.
He did say to expect the warranty claim to be rejected but I’ve not talked to him to establish why - it could be on the basis of experience, age of frame, that the bike is ‘modified’ from factory spec, or just that there are too many unknowns in the 3 years I have had it.
I’ve also tried my bike insurer, they said it is either wear and tear (and not covered) or a warranty claim (in which case CSG who import Cannondale should deal with it). Is what I expected but certainly they will not engage me further on it until I have a professional opinion.
Man that’s unfortunate and I’m sorry to see that you confirmed your suspicion. I hope that Cannondale takes care of you. I wonder if the ferrule or PTFE coating on the cable is supposed to prevent this and if there is any recommended interval at which to replace or inspect these things.
Sounds like Cannondale (or the UK importers) will be warrantying the frame.
It isn’t the same colour way I had, or indeed one I’ve seen in the UK, but is a predominantly black size 52. Edit - looks like a 2016 Black Inc framset.
I do recall reading about some early CAAD12s in size 52 (or maybe 50) and below having different geometry, rumoured to be the wrong rear triangles fitted, but that this was resolved post 2017.
Edit found the link:
Further edit:
That colourway shows in the 2016 catalogue as the ‘Black Inc’ model.
Either way I am taking up their kind offer, infinitely better than the position I expected to be in!
I think I’m going to go ahead and do the same on my Caad12. I have tried running just a housing inner through the frame which helps, but still not very smooth…This seems to be a pretty easy fix.
Well…about 6 months ago, my front derailleur cable sawed my crank spindle in half. Bike shop found out for me that cannondale had put out a service bulletin regarding the plastic cable guide under the bottom bracket failing. I bought the new metal reinforced one, and my shifting has been great ever since. However, the rear brake has always been pretty rough. I did find that lubing the hell out of the entire cable helps but that only lasts a couple weeks. I have pinpointed the problem to cable rubbing inside the frame. I really love the bike other than that…and don’t really want to go through the disappointment of trying to prove a case for warranty. Maybe I’ll call the bike shop and see what they think. Anyhow, I was a machinist so I’m comfortable just drilling out the cable entry/exit holes and putting a cable housing all the way through the frame.
Hi folks. Just came across this thread when searching for CAAD12 rear derailleur cable replacement.
Shifting poor on my rear derailleur. Cable needs to be changed. But see the attached photo. I gave the bike to a mechanic a few months ago to replace front derailleur cable. It’s looks like the cable guide cover wasn’t replaced correctly (there is a gap between the cable guide and the frame) and when I replace it correctly after installing new RD cable it’ll change the tension of FD cable and so will have to also set up FD again? Am I correct with this assumption?
Also, when I’m replacing the rear brake cable on this bike I guide an old cable liner over the old inner cable through the frame so I can easily guide the new inner through the frame (if that makes sense). Is it possible to do the same for the rear derailleur cable?? Is it possible to use a full length cable guide from top of downtube to end of chainstay?
Thanks!
You are right, to do one you disturb the other , so do both FD and RD at the same time, take the opportunity to replace the cables, ferrules on insert to frame, outers and clear plastic straws whilst it is all off for the sake of the cost.
From experience I would go for an uncoated high thread count stainless cable and leave it well lube through the outers and straws. Make sure cable and outer are the same diameters.
I don’t think the RD cable can be setup with a full length outer as it won’t clear the crank spindle. Certainly this is true on a 30mm, it would end up rubbing on the outer and could leave a mess inside the frame.
A magnetic internal cabling kit makes cabling these bikes up a really simple job.
Good luck and hope you don’t find the cables have been eating the frame apart.
Thanks! I did it yesterday without too much fuss. But what a b@lls having to undo FD also. Haven’t been able to get that adjustment correct again. I’m either getting sight rub in big big or slight rub in big small. I had it perfect before
Also ordered some cable liner because the existing ones are filthy
Just can’t believe you’ve to undo both cables in order to replace one. Nuts.
