Jagwire replacement - Newbie alert!

[Running_Man]

I need to replace the derailleur cable housing on my son's Riprock 20, as it has split where it meets the cable tensioner on the derailleur, inner brake strands poking out everywhere! So what do I need to buy based on the spec below? and do I need any special tools to fit it? I have most tolls in the toolbox

- Jagwire Lex
- The housing runs in one piece from the derailleur to the revoshift
- The derailleur is a Tourney TX

Any help appreciated :-)

[Kermit power]

Running_Man said:

I need to replace the derailleur cable housing on my son's Riprock 20, as it has split where it meets the cable tensioner on the derailleur, inner brake strands poking out everywhere! So what do I need to buy based on the spec below? and do I need any special tools to fit it? I have most tolls in the toolbox

- Jagwire Lex
- The housing runs in one piece from the derailleur to the revoshift
- The derailleur is a Tourney TX

Any help appreciated :-)

Firstly, just in case you're not aware of this (and saying it based on the bold above), brake and gear cables are NOT interchangeable. Brake cables only have to pull, whereas gear cables have to both push and pull, but with less effort required, so they are built differently, even if they might well look the same.

[Barchettaman]

It´s a 7-speed kids MTB, brake housing will be fine if that´s all you have on hand.

You need a long length of (ideally) derailleur housing, Jagwire is nice stuff if you have it, and a derailleur cable, 2 ferrules (outer caps - you might be able to reuse the old ones) and an end crimp (or a dap of hot glue) to stop the cable end fraying.

Make sure the barrel adjusters on the lever and rear derailleur are wound all the way in (clockwise) before you bring the cable up to tension.

[Running_Man]

Thanks for the replies guys, I'll give it a go & report back

[gazza285]

Kermit power said:

Firstly, just in case you're not aware of this (and saying it based on the bold above), brake and gear cables are NOT interchangeable. Brake cables only have to pull, whereas gear cables have to both push and pull, but with less effort required, so they are built differently, even if they might well look the same.

What rubbish, gear cables do not push.

Gear cables are thinner, have a smaller nipple, and the outer will probably be compressionless to help with indexing accuracy. You don't need to use Jagwire, other brands are available...

[Kermit power]

gazza285 said:

Kermit power said:

Firstly, just in case you're not aware of this (and saying it based on the bold above), brake and gear cables are NOT interchangeable. Brake cables only have to pull, whereas gear cables have to both push and pull, but with less effort required, so they are built differently, even if they might well look the same.

What rubbish, gear cables do not push.

Gear cables are thinner, have a smaller nipple, and the outer will probably be compressionless to help with indexing accuracy. You don't need to use Jagwire, other brands are available...

Giving thought to the process, I suspect you may be right and my LBS - when explaining why I couldn't use what they had in stock - may be wrong. Methinks I may choose alternative LBS'es in future!!

[AlmostUseful]

He is indeed quite right, brake outer is coiled to allow some give when braking - modulation if you will, gear outer is stiffer to ensure accurate shifting.
Gear cable is pulled to fight the return spring in the mech, and the spring then return the shifter to its natural position.

[Barchettaman]

Plus you should never use shifter housing or cales for brakes! The housing can fail.

I've use brake housing for 7- and 8-speed setups in the past, works absolutley fine.

[The_Jackal]

Just buy a gear cable and outer set from Wiggle and then no uncertainty about whether it is the right stuff or not.
For what little cost they are, it is not worth using old outers and your gear changes will be better.