Gear Cable

[Gummo]

The rear derailleur gear cable on my Giant Escape 0 bike has snapped. The shifter is a Shimano Deore Sl-M610. The cable housing says JAGWIRE LEX which is eroded at one point.

I've never had to replace a gear cable or housing - are they all universal?

[jb]

Usually they are, some expensive ones claim to have less friction. Just buy a new gear cable and a length of outer sleeve and cut them to the same length as the old ones (best done with proper cable cutters that won't splay the ends). Thread the cable through the shifter and the outer sleeves and bolt to the derailleur before cutting off the un needed length, leaving enough to grab hold of if you ever take it off and need to re-fasten it.

[richardfm]

Have a look here for more detail https://www.parktool.com/en-int/blog/re ... le-housing

[PT1029]

Outers are sort of universal.
You will need the linear stranded outer as per your picture, not spiral wound outer (too squidgy for indexing), Shimano do make spiral indexed gear outer for their cheap gears, avoid if you can..
Also they come in 4mm and 5mm outer diameter.
Use 4mm or 5mm?. I guess the 5mm outer has more inside space for the inner cable to move through which I count as a plus.
As I use 5mm brake outer, I use 4mm gear outer so it is easier to see which is which in the workshop - something I did when running a shop and I knew some of the apprentices/mechanics (more former than latter!) were not always as attentive to detail as they might have been.....
The linear strand outer needs to have a cap/cup on each end of the outer otherwise they fray/collapse. Make sure you get end caps/cups that match the diameter of your outer.
If you have cables running inside the frame, don't just pull the old cable out - use the end of the old inner cable to thread the new outer through the frame. There are threads somewhere on this forum and others about inside the frame cables - the thread usually started by someone who has pulled the old cable out and can't get the new cable through......

[Gummo]

I managed to get the Jagwire gear cable and housing for £5 - the housing is exactly the 1 metre length of my existing housing.

[alexnharvey]

Do you know what has rubbed against the outer cable to cause the wear and can you prevent it recurring?

Also, if you can file the ends of the cut outer cable flat before putting the caps it makes a neat job.

[Gummo]

Do you know what has rubbed against the outer cable to cause the wear and can you prevent it recurring?

The fork's paint has rubbed off at that point - can't see what I can do. Anyway, the original housing and cable survived the first 8 years, so I'll be happy to give the new ones another 5 years - when I'll be 70.

[alexnharvey]

I find frame protection tape seems to help the outer slide rather than rub.

[Gummo]

I find frame protection tape seems to help the outer slide rather than rub.

Any recommendations on such tape and on paint to cover the bare patch on the fork?

[alexnharvey]

"helicopter tape" is the best stuff. You can buy small amounts from eBay. Even a piece of insulating tape is better than nothing and can let a long time if the surface is clean before it's stuck on.

Car touch up paint is probably the easiest way of getting paint that's a reasonable match to the bike but people also use small tins of the enamel used for model building or even nail polish.

[peetee]

On frame/cable contact points I use rubber boots designed for the exposed cable between V-brake arms.

[Mick F]

Cables are "sort of universal" but some are far better than others.
I like Campag because they are lubricated for life.
Jagwire are excellent, but your standard Halfords etc stuff or stuff you can get off eBay are very middle of the road.

I have a mixture of Shimano, Campag and Jagwire on my Moulton.
Shimano for the front brake and front mech, Jagwire for the rear brake as it has a very tight turn and needs low friction, and Campag for the rear derailleur which has quite a long run.

My advice, is that if you're happy with what you have and it needs replacing, replace with like-for-like.

[alexnharvey]

I think that the die drawn stainless cables are good and the ones with surface polishing are the best and pay extra for them. I prefer the polished cables to teflon coated cables. Jagwire have a handy guide to inner cables which describes the differences. https://jagwire.com/guides/inner-wire

You might decide based on cost or availability that die drawn are 'good enough' and extra polishing is not necessary.

[TheBomber]

The fork's paint has rubbed off at that point - can't see what I can do.

I'm surprised that your 'rear gear cable' touches your fork at all. Was it excessively long?

I managed to get the Jagwire gear cable and housing for £5 - the housing is exactly the 1 metre length of my existing housing.

This makes me think that somebody previously bought and installed a standard length of outer without cutting it to the optimum length. Perhaps because they didn't have any cutters.

Maybe a photo or two of the 1m outer in place showing where the cable has been rubbing would assist here?

[Gummo]

This is the bike the day I bought it new. Top of the fork is the erosion zone.