how do you tell the difference between it and a brake housing. I went into my lbs today and bought some. The kid did seem know what i was talking about but in the end i ended up what i believe to be brake housing.

Not a huge problem but since im running downtube 9 speed indexed shifters id like to have the real thing so i dont have to keep fiddling with it to keep it ajusted. IS there a way to visually tell the difference?

THis stuff is not braided and it isnt cable strands...it is that metal stuff that spirals down the housing. You can see the "rings" right through the black colored housing. That right there tells me it is likely 5mm brake cable housing. The kid rang it up as SIS shifter housing.

https://www.parktool.com/blog/repair-help/housing-length

saw that earlier today.

Brake housing for sure....

THis shop has a friendly staff and all but it seems more often than not.....i walk out with the wrong thing.

Frustrating. How do i go back and complain? I spent less than $3 and i feel bad going back and explaining that they sold me the wrong thing....
It seems the owner is the only one that knows what he is doing.....everyone else......not so much.

If you're really running downtube shifters than the only piece of cable housing you need is a 12in or less piece just before the rear derailleur. And there is absolutely no issue using a spiral wound cable for a length that short. Shimano did and still does it all the time. It'll actually take a shorter radius bend than compressionless housing.

thanks!

I plan to try it just because i cant bring myself to bring it back and complain to a local small shop....especially for $3

That's fine, and it's a refreshingly positive attitude. But you should drop in and let the owner know that his staff needs a bit of basic training. The difference between brake and index housing is something that staffers should know, or at the very least know that they don't know.

These days it seems that nobody is willing to say "Gee, I don't know, let me ask someone who does".

In this case there was little harm done, but if the person had sold index housing for brakes it could have been more serious.

Damn straight... the owner needs to know the situation.

i suppose.....

hopefully the owner wont take offense or anything......the workers there are his kids.....and this one was his daugther

Not if you approach him in a positive way. Let him know you're not complaining, just letting him know.

Concur, you may be helping the owner in the long run. In fact, the owner may be led to falsely believe everything is fine if no one provides feedback, until something major happens. As long as you mention it tactfully, the owner will appreciate it. I guess consider your comments a feedback and not a complaint. And as a solution, you can mention perhaps they can label the housing (I assume it's a large roll) to help the workers. I guess the owner can just label the housing roll as a subtle hint to the workers.

Or better yet, just teach them to distinguish the two by explaining why they're different.

what sort of issues would one see if they were to use brake cable housing as derailer cable housing on a brifter equipped bike?

Brifters use relatively long housed cable runs from the brifters themselves to the housing stops on the downtube or headtube and these housings must flex noticably as the bars are turned.

Purpose built shift housing has the reinforcing wires run pretty much parallel along its length and maintains it's overall length as it is flexed. Therefore, it doesn't lengthen or shorten and doesn't pull on the inner wire and change the derailleur position. That stable length under flex is necessary for accurate indexing.

Brake housing has tight spiral wound reinforcing wires which give great burst strength (essential for resisting braking loads on the inner wire) but allows the length to change a bit as it's flexed so it's not as good for indexing. That's also the reason you don't use shift cable housing for brake housing.

The OP was only going to use a very short piece of housing in an area that flexes very little so the fact he got brake housing won't matter.

thanks for the thorough explanation! makes sense now.