Rattling noise in specialized with internal cable routing

rocky.raccoon

A question to those who build bikes up with internal cable routing.

I've got a Roubaix road bike. The internal cable is making a rattling noise within the top tube.

According to Specialized (video: http://servicevideos.specialized.com/video/23917838) I need to slide some o-ring or cable donuts onto a short piece of cable sheath and then slide it onto the rear brake cable and into the top tube.

I've removed the internal brake cable and could not find any donuts or sheath. Unless they fell inside the tube frame. Is it possible?

I've already got the cable donuts. My question is: do I really need that piece of cable sheath? Is it absolutely necessary? If yes, where do I get them from? Could I just use the cable donuts without the sheath?

Cheers

wishitwasallflat

Perfectly possible the sheath slipped off but I would have thought you would see it or hear it rattling about. You do need some sheath not good to have bare cables and donuts. New sheath here

http://www.uk-hooks.com/details.php?selected=705

rocky.raccoon

Thanks for your help. Could I just slide the O-rings directly on the cable? Why is the sheath needed? Also if it is really important why is not widely available on cycling websites and shops instead of fishing gear website?

wishitwasallflat

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19677739#p19677739]rocky.raccoon[/url] wrote:

Thanks for your help. Could I just slide the O-rings directly on the cable? Why is the sheath needed? Also if it is really important why is not widely available on cycling websites and shops instead of fishing gear website?

I don't have a good answer but -

AFAIK all bike manufacturers fit sheaths to internal cabling. Makes me feel there must be a reason.

No logical explanation but I just feel uncomfortable about the idea if a bare cable in there, does it rub maybe?

I expect bike shops don't sell it cause it comes in all frames as standard and cause its thicker and often joined to the grommets at entry points so doesn't go missing.

As I said not very good answers just how I feel myself.

chris_bass

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19677686#p19677686]wishitwasallflat[/url] wrote:

Perfectly possible the sheath slipped off but I would have thought you would see it or hear it rattling about. You do need some sheath not good to have bare cables and donuts. New sheath here

http://www.uk-hooks.com/details.php?selected=705

sorry for not adding to the thread - but thanks for the link, been looking for some of this for a while!

rocky.raccoon

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19679952#p19679952]Chris Bass[/url] wrote:

sorry for not adding to the thread - but thanks for the link, been looking for some of this for a while!

Just a quick update..

If you strip a break cable you will find that it has three layers put together. An exterior plastic sheath to protect the cable, a steel layer that gives the cable it’s strength and a also a plastic tube inside the steel layer.

An inner brake cable runs inside the plastic tube. That is the piece of cable sheath we need.

Cheers