Shimano "SIS" Cable Housing

wheelsgoround said:

I quite often encounter gear cable housing, used on indexing systems, with the marking "SHIMANO
SIS" This would lead one to believe that the housing is of the compressionless variety, which is
required for correct operation of the indexing system. On inspection of the housing, it turns out
to be spiral-wound.

Is this genuine Shimano housing? And, if it is, are Shimano saying spiral- wound housing is
acceptable for indexing systems? I have read in a number of texts words such as "Do not use
ordinary wound housing; use a housing such as Shimano SIS" This becomes all very confusing.

For what it's worth, the housing marked "SHIMANO SIS SP" is of the compressionless type.

Quoted message said:

Some bike designers would rather save a couple of dollars per bike by using the cheap stuff. And
they also would prefer to have Shimano's name on the casing. When you buy derailleur ensembles
50,000 at a pop, you can have nearly anything you want!

(Hmm let's see, you save, er, let's say about $3. . . x
50.000. . . per brand per year. . oh, I get it.)

Yep, I bet if they asked, Shimano would even write them a bike owner's manual recommending it!

Of course if you want the system to shift well, use high-helix casing.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

Quoted post said:

Originally posted by wheelsgoround
I quite often encounter gear cable housing, used on indexing systems, with the marking "SHIMANO SIS" This would lead one to believe that the housing is of the compressionless variety, which is required for correct operation of the indexing system. On inspection of the housing, it turns out to be spiral-wound.

Is this genuine Shimano housing? And, if it is, are Shimano saying spiral-wound housing is acceptable for indexing systems? I have read in a number of texts words such as "Do not use ordinary wound housing; use a housing such as Shimano SIS" This becomes all very confusing.

For what it's worth, the housing marked "SHIMANO SIS SP" is of the compressionless type.

Any ideas?

Shimano SIS SP is the kind you should use for your STI shifting cable housing. Shimano SIS SP is not spiral wound.
I think your understanding of what is required is correct.
Verify your observations and check with Sheldon Brown's site on cables at URL:
http://sheldonbrown.com/cables.html

On Tue, 13 Jan 2004 20:10:49 GMT, wheelsgoround

may have said:

I quite often encounter gear cable housing, used on indexing systems, with the marking "SHIMANO
SIS" This would lead one to believe that the housing is of the compressionless variety, which is
required for correct operation of the indexing system. On inspection of the housing, it turns out
to be spiral-wound.

It's not whether it's spiral-wound, but *how* it's made spiral-wound, that determines the
suitability of a housing for use in a given application. This same general observation is true for
many other things as well.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
Words processed in a facility that contains nuts.

wheelsgoround said:

I quite often encounter gear cable housing, used on indexing systems, with the marking "SHIMANO
SIS" This would lead one to believe that the housing is of the compressionless variety, which is
required for correct operation of the indexing system. On inspection of the housing, it turns out
to be spiral-wound.

Is this genuine Shimano housing? And, if it is, are Shimano saying spiral- wound housing is
acceptable for indexing systems? I have read in a number of texts words such as "Do not use
ordinary wound housing; use a housing such as Shimano SIS" This becomes all very confusing.

For what it's worth, the housing marked "SHIMANO SIS SP" is of the compressionless type.

Any ideas?

I'm not skeptical enough to believe there is counterfeit Shimano housing out there.

I have observed that the ordinary spiral-wound housing marked Shimano SIS is usually only installed
as the last loop to the rear deraileur.

In the mid eighties, this was the only derailleur housing most road bikes needed (down tube
shifters), and in my experience it was less compressible than the common Campag and SunTour
stainless housing (spiral wound with no outer plastic sheath).

On MTBs the high-helix Shimano SIS housing was used on all but this last loop.

Modern Shimano SIS housing is all high-helix, even the last loop to the rear deraileur.

Shimano SIS housing has plain holes in the end caps. Shimano SIS "SP" housing has tiny rubber seals
in the end caps.

Thanks for your replies, guys.

I am pretty clear in my own mind that compressionless housing should be used.

I guess my question was "Are Shimano saying (by marking it SHIMANO SIS) that wound housing is acceptable for index systems?" I have looked at Shimano's service instructions for various indexing systems and they all recommend "SIS-SP" cable.

Although I have encountered the SIS wound housing on numerous bikes (both on the shifter loop and the rear derailleur loop) I don't know whether it is still being fitted to new bikes or whether Shimano still produce it.

The other thing I forgot to mention is that some of this "SHIMANO SIS" marked housing is lined and some of it isn't. Surely the non-lined stuff is completely inappropriate for gear systems, so how it can be classified as "SIS" I don't know. Maybe this non-lined stuff is obsolete; as far as I can remember I have only seen it on "old" bikes.