My ancient aluminum P3 is set up to allow a derailleur cable housing ferrule to insert into. I'd be really surprised if your P2 isn't supposed to be set up that way as well. Is your frame missing the piece that fit into the frame that hold the ferrule?



It also appears that the P2s have a similar piece in this photo.

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Genetics load the gun, lifestyle pulls the trigger.

The frame routing hole should be large enough to accommodate a housing end cap. The generally are tight, but can be fed in at the right angle. Has your frame ever had one?

If your frame hole is out of tolerance (too small), it seems you might have a legitimate warranty issue. ...Without an end cap, the twisted cable will be gradually putted out of the housing with every shift, resulting in continuing shifting problems.

looks like you are missing a ferrule. install one and report back in a few months.

this was actually somewhat common due to paint over spray. easy to fix, just use a circular file to open up the hole to original spec.

https://www.excelsports.com/main.asp?page=8&description=Toptube+Internal+Cable+Stop&vendorCode=CERVELO&major=11&minor=11

WHS^^^

It's tight but you should have a cable end cap which does fit: need to ensure when it's inserted the cable goes close to the tube.

They don't have metal frame inserts at these points (but you should have one for the rear brake where it enters the frame).

Thanks for the replies everybody! Very helpful so far.

Sciguy, Beston and others: Exactly, it seems to miss the piece that fits into the frame. I bought the bike 2nd hand about 1000 miles ago, but I do not remember whether it had this piece or not.

Lightheir: thanks, I'm sure that is the piece I need. Unfortunately they do not ship to Europe. Do you think something like this could work as well? https://www.sigmasport.co.uk/...stay-Cable-Stop/BXC1

You don't need that piece. That is a rear derailluer cable stop used on current generation R and S series bikes that route the gear cable internally. That piece is at the rear chainstay/seatstay. Your P2 has a cable stop that is riveted under the chainstay.

All you need is the Shimano plastic cable ferrule. It can be a tought fit sometimes. Like someone else posted above, there may be excess clear coat paint that needs to removed in order to get the ferrule to sit in properly.

https://www.ebay.co.uk/...trdt=0&rdtsrc=vi

Yeah, I agree. As soon as I posted that response, I thought that getting rid of a bit of clear coat could easily fix the problem. Having a ferrule on the end of the housing is really key to properly guiding the cable into the frame.

You need a 4mm cable housing ferrule like this (your LBS likely sells it for cheaper):

http://www.chainreactioncycles.com/...%7C%7Cprd%7C550911CA

The importance of this is (1) it keeps the cable housing from 'stretching' (that's the simplest way to put it), and (2), it will help properly seat/guide the cable into the frame to reduce all this friction you are describing.

If the hole is too small, perhaps you should consider lightly filing the clear coat inside this space.

A quick fix (for the moment), would be to zip tie the derailleur housing together above the top tube. This should help keep the housing tight to the frame (rather than flared out), allowing the cables to move through the frame better.
example: http://www.cyclingnews.com/...ement-in-california/

A proper fix is to make sure that you are using 4mm cable housing AND a 4mm housing ferrule properly in the frame. I've seen some 'universal' 5mm shift cable that certainly would NOT fit inside that cable stop.

A more involved fix (I have done a similar mod to my P4), is to completely reroute the cables through the top tube as TriRig has described. However, I think that this might be too much work for the less experienced wrenches.
http://forum.slowtwitch.com/...ntable;post=4002447;