Hello,

I'm fixing up a road bike I have. It has a short section of Cable housing for the rear derailleur that loops up and around and the into the rear derailleur. All together it's maybe 5-6 inches. About halfway through the housing is sliced open sort of diagonally allowing you to see the bare cable inside.

The derailleur functions correctly and the cable appears to be keeping it's tension. I don't really want to buy another length of housing for such a small section. Do you think this is a hazard as it is? Would you wrap it with electrical tape or similar to keep the debris out but consider it fine otherwise?

Or should I replace the housing in fear that the cut may become larger making the cable loose tension and potentially throwing the derailleur into the wheel?

Thanks!

time for new housing and cable

The failure of the housing will not result in the derailleur falling into the wheel, simply because the range of the derailleur is determined by the limit screws, not by the derailleur cable. If your cable housing is the constant-length type (i.e., correct for derailleurs but may be deadly for brakes), just wrapping the damaged part with tape will probably be OK for a while. Don't use electrical tape as that may be too stretchy; use something like fiberglass packing tape or another tape that is dimensionally stable.

May I suggest just visiting your local bike shop and asking for an old length of housing? Bike shops usually have bits of used housing in the trash that are not new but may be better than your damaged housing.

Bike coops have TONS of short pieces of cable housing that they will let you have for nothing most likely.

OK, the worst case with this is that you'll have to replace it eventually, probably sooner rather than later. Since it's working though split, either the inner liner is intact and holding it together, or you have a short spiral brake type housing which doesn't depend on the cover for support.

Either way there's no likely untoward consequences from leaving this as is. Bad housing cannot cause the RD to go into the spokes, that's done with a correctly inner limit screw. Since the cable pulls the RD inward against the spring a total cable failure of any type will cause the RD to shift outward and have you riding home in high.

So yes it's die and you'll have to replace it, but don't lose anything by waiting until you have no choice.

Post a photo?

Thanks for the responses, everyone. I think for now I will tape it up with some strong tape since it doesn't pose a serious threat.

Thanks!

I'd replace it now so it doesn't explode into this while you're out riding:



...which would not be fatal, but would be annoying if you didn't have the tools with you to lock it into a tolerable gear.

Great photo. I think (hope) that if his housing looked like that the OP wouldn't have asked.

I agree it should be replaced. Why go through such hassle when you could buy a new foot of housing for less than $3? You could probably get used housing for way less than that.

You're not serious, are you? C'mon, man!

All it takes is five minutes, a cable end, and a short piece of housing!

If a worthless POS like me can replace one then ANYONE can do it!

When you replace it, might as well redo the whole run; using the spiral type brake housing. This way you'll never have to worry about splitting again.
As long as your shifting isnt some super sensitive 11spd cassete brake housing will work fine.

Just make sure you don't use brake housing, it is spiraled and has a tendency to cause ghost shifting but honestly, that is mainly a problem for the housing ends by the handlebars since they move. It is more of a big deal if you have any type of index shifting especially if you are at 8 speeds or more. If you must use spiral brake housing, only use it for sections that don't move.

I wouldn't try using brake housing above 7spd. The RD loop changes radius quite a bit between big/big and small/small.

I personally don't use brake housing for anything that's above 6 speed. Good shift housing is designed to be compressionless, standard brake housing is not... My shop sells YPK compressionless shift housing in black or grey for $2 a foot including housing end-caps... It's a no-brainer if you ask me.

I don't use brake housing for anything above five speed.

For sure.

1. No, it would be a potential hazard - is that not enough?

2. No. Not any more than I would patch a tube with electrical tape to keep out debris. The housing is functional, not decoration.

3. Yes - or you could wait for a problem when you are 10 miles from home.

You guys are just hacks, there's no way I'd use brake housing for anything over 4 speed.

- Joel

I've used brake housing on friction-shifted 7-speed. Works like a charm.

I break out the shifter housing when wishing to index across a cluster of any cog count with a derailer.

Brake housing should be fine for friction shifting with any number of speeds, since you'll prolly still have your hand on the lever by the time the housing finishes moving.

But gear housing should make it more responsive; this will be more noticeable the closer together your cogs are.

I'd never use it on anything over single speed. Yeah that's right, I only use it for brakes.

I never use brake housings.. , actually I never use brakes, I stop by throwing an anchor.

On kludges on bikes I've seen, brake housing on shifters seem to be the main theme - waiting for hydraulic lines repurposed for cable housings