Gummomarx

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?

Jeff Neese

Yes, they're universal and Jagwire is a good choice. You'll obviously want to correct whatever caused that cable to abrade the way it did. Here's a video showing how to change the cable on those shifters.

dedhed

You need high quality cable/housing cutters to do it right, especially on indexed (compressionless) housing. An alternative is to take the housing pieces in to the LBS and buy it off their bulk roll and have them cut it to the lengths you need. Inner cable you can use lesser tools. Also replace all the housing ends (ferrules).

Andrew R Stewart 

Before the cable and housing is replaced look at the original set up for any possibl;e changes with the new. The imaged housing damage is likely from rubbing against a tire or some other thing. Avoiding that again is a good goal. By changing the housing loop's length one can affect where the housing runs and whether it rubs on something (and check with the steering at 90*, not just with the bars point straight ahead).

Indexed housing wants a more controlled cutting method that the tight spiral brake housing needs. A Dremel tool with a cut off disk works well but most will use a "proper" housing cutter. This is why many home mechanics will have the LBS do the indexed housing cutting, saving the cost of the special cutter that won't get used at home very often. If you do this make sure your housing length needs are well determined before going to the LBS.

While you are installing the inner cable into the shifter take the time to lube the shifter internals. Andy

Gummomarx

I managed to get the Jagwire gear cable and housing for £5 - the housing is exactly the 1 metre length of my existing housing. The original has lasted 8 years, so I'll think about replacing it again in 5 years.

hokiefyd 

What do you reckon abraded the original outer housing like that? That's some pretty serious and concentrated wear...you'll definitely want to try to migitate this for the future (any water intrusion will degrade shift cable performance long before anything physically breaks).

Gummomarx

Rubbing against the fork whose paint has worn off at that point. The bike came as new with that cable arrangement.

hokiefyd 

You might consider an alternate cable routing, assuming you have cable stops at the top of the down tube or full length cable housing. The right/rear cable housing typically passes from the shifter on the drive side of the bike down along the drive side of the head tube and into that drive side cable stop. That usually causes a pretty forceful rub against the head tube. Likewise, the front/left cable housing is on the non-drive side of the head tube, rubbing the paint there as well.

An alternate routing is passing the right/rear cable housing across the front of the head tube and down the non-drive side...and passing the left/front cable housing across the front of the head tube and down the drive side. Then, let the cable housings (or exposed cables) make a very gentle X under the down tube, returning them to their conventional locations near the bottom bracket. This eliminates that rub at the head tube and also allows for more relaxed bends in the cable housing (which can improve shifting).

Any friction of exposed cables crossing each other under the down tube is negligible.

Lombard

How many miles is 8 years? Regardless, a cable abrasion like that is preventable and should not happen. You may be able to prevent it by using a longer piece of housing on that section. As others have said, there is a special cutter designed just for that. Don't use standard wire cutters as they will fray the cable end and mash the housing end. Even with the special cutter, you may have to reem the end of the housing so the end of the housing stays a circle, not an oval, otherwise that will be a cable friction point.

Gummomarx

Someone recommended 'frame protection tape' to protect the fork.

Gummomarx

I have neither, sadly.

Lombard

This is a good idea to protect your frame, but may not do much to protect the cable.

veganbikes

That is not a source of pride, that is a sign of a lack of maintenance. Housing should not wear like that and it is not ideal to leave stuff that long especially to get that damaged. Also I wouldn't put that cheap of a cable and housing on a bike. Cables and housing are a good cheap way to improve shifting and braking and more than likely that $5 (or pound) stuff is the basics stuff with cheap galvanized cables and non-lubricated non-compressionless housing OK for a cheap bike or something with friction shifting but I wouldn't unless I had to. Sport is the way to go if you want to save money but get good quality and Pro and then Elite if you really want an improvement.

If you are riding the bike regularly I would probably replace cables and housing at least every couple years or so if not sooner. I mean you should be tuning the bike at least once a year and more as you ride more. Keep the bike running well and it will last a long time. Maltreat and let problems get worse and worse and you will spend a lot of money in the long term.

In this particular case you need longer housing so you don't have the issue again hopefully but you still need maintain and take care of your bike and check for issues like this.

hokiefyd 

You generally have one or the other, unless the cables are routed internally through the frame tubes. Unfortunately, internal routing may limit your options here, especially if that internal routing is fully sleeved, meaning the cable "track" through the downtube is defined by a small sleeve and can't easily be changed. The small bits of protective tape may be your best bet.

Gummomarx

The day I got it - gear cables just clipped to the clipped to the underside of the downtube.

Gummomarx

I just don't have the time to allocate pride to something I look upon as a tool that gets me to all the mucky places where I take photographs of landscape and nature. I was extremely happy with the bike's performance since I got it on my retirement 8 years ago. I don't care if the cable snaps again when I'm 73 - in fact, I'll be glad if I haven't.

dedhed

before you install,l take a piece of the housing to the local hardware or auto parts store, find some rubber or tygon tubing that fits over the housing, and add a few inches where it hits the frame/fork

Lombard

You do have a point here. And 8 years is a good run. However, you really don't want your frame eaten into more than it is already. Definitely get some of that tape that protects your frame. Another option are rubber housing sleeves that slide over the housing which you can place right in that area.

Gummomarx

I've painted some black acrylic matt paint over the wee bare patches and I intend to tape over that as you advised. Do you have any links for those sleeves?

Lombard

Scroll down to "Cable Management & Frame Protection":

https://jagwire.com/products/small-parts

veganbikes

I think you misread what I wrote but having a cable rust and housing that wears through because you didn't change it is not a good thing and not something that you want to have happen. Taking care of your bike is very important and will prevent issues like this from ever happening. Cables, housing, brake pads, chain, cassette/freewheel),bar tape...are all wear items and will need replacement generally sooner than every 8 years and especially before they just completely fail. You should care if the cable snaps that is generally not a sign of a magical mystery but a sign of poor care on a bike (though not always but in this case, yes). If you don't want to do the maintenance, that is totally fine, time is valuable so take it to a shop once a year and let them care for it but keep it running if you enjoy it there is zero reason not to.

If you are frequently in places with muck and going off the beaten path that is even more reason to maintain it with regularity. You are already talking about taping your frame to prevent damage to it but it seems like you are fighting maintenance which is way more important and will generally prevent paint issues (which eventually if given enough time could actually damage the frame but the full paint is usually thick enough.)

If you love the bike, love the bike!

Lombard

The OP never told us how many miles 8 years was. 500 miles per year or 5000 miles per year? This makes a huge difference in how often general maintenance needs to be done unless the bike is stored in a hostile environment exposed to the elements.

hokiefyd 

Thanks for the picture...it does look like you indeed have full length cable housings, so you probably could cross them under the down tube for easier and less aggressive bends up front. It's not a huge deal, though...just keep an eye on the condition of the housings in the future.

veganbikes

Yes and no to an extent. I tell people once a year bring it in for maintenance nearly regardless just to keep everything in tip top shape and ready to ride when you want it and just keep an eye on it. If you have a regular schedule once a year it will help and if you are riding that 5k or more a year than probably a bit more often. But it is good to just get it out of the house once and while and recognize you still have it and just make sure everything is adjusted and any old worn parts are replaced to keep it going for a long time as possible.

It may not need a full tune but even asking a mechanic to just go over it and just lube stuff and clean a little is never a bad thing but in many cases if you are using it, it should need some love especially in situations like this where the bike is being put into situations where serious damage is occurring to parts on it. When housing is worn through and the cable is rusted and the cables haven't been replaced in 8 years the numbers of riding matter less and less because you can tell the bike isn't maintained regardless of mileage.

Gummomarx

864 average per year according to my app.