Replacing rear gear cable on Cannondale

[wyre forest blues]

I appreciate there are previous posts on replacing internal gear cables. However on my Cannondale Synapses the cable runs internally in the downtube and the chainstay. At the service port on the bottom bracket the inner cable is protected from the elements by a thin outer plastic sheath, which appears to have an internal diameter just large enough to accommodate the inner cable Can someone advise the best way to thread the new cable in the downtube and through the plastic sheaf. Do I need to remove the crank arm spindle to access, or perhaps can the outer sheaf at the BB service port be removed and reinserted?

 

[gazza1286]

You will find that it will be far simpler to remove the service port plug entirely. Obviously this means that both the front and rear rear cables will need to be swapped as the plug cannot be removed unless both cables are unthreaded. The out protective sheath can be reused and once the plug is removed you'll have no problem.
Given the size of the plug you shouldn't have any issues getting the cable from the headstock to the bottom bracket.
Park do an internal routing kit with magnets etc which no doubt you'll be aware of but you shouldn't need that.
I'm unfamiliar with the Cannondale but Scott have a very similar set-up where you're obliged to disconnect both cables to gain access. This of course means that both cables will need swapping due to fraying etc.
Good luck.

 

[wyre forest blues]

Thanks Gazza. Once the cables are removed do you think or know if the plug pulls or drops 'out' or will I need to access it from the inside by removing the crank arm spindle.

 

[gazza1286]

The plug on the Scott is only an interference/friction fit. The tension of the cables keeps it in place. I suspect yours will be the same.

 

[wyre forest blues]

Gazza,
That's great, thanks for your help.

 

[cyberknight]

You can get internal cable threading kits

http://www.wiggle.co.uk/park-tool-internal-cable-routing-kit/

 

[Globalti]

On my Roubaix and my son's Tarmac the cable finds its way out of the service port and then out of the end of the RH chainstay without too much trouble, often at the first attempt. It's not as big a job as you fear. Just gently push it along while wiggling it a little.

 

[pclay]

Looks like a Cannondale synapse tiagra 2014 to me. I have the same bike. The plastic cable guide just pops out. No need to remove cranks.