Converting a Brake Cable To a Shifter Cable
Bret Cahill
Bret Cahill
Qui si parla Campagnolo
> Torch the end and shake off the solder until only a small nib is left.
>
> Bret Cahill
Or go down to the bike shop and buy one. That brake inner wire isn't
going to fit well and smoothly in 4mm housing, BTW-
sodaquad
> Torch the end and shake off the solder until only a small nib is left.
>
> Bret Cahill
Don't. Brake cable is slightly elastic - so that it's very strong.
Gear cable is more rigid - for precise shifting - but that makes it
more brittle. It is dangerous to use gear cable for brakes, and brake
cable is too stretchy for gears.
Simon
Bret Cahill
> Gear cable is more rigid - for precise shifting - but that makes it
> more brittle. It is dangerous to use gear cable for brakes, and brake
> cable is too stretchy for gears.
Fortunately the metro bus managed to stop when I couldn't get into the
small chain ring in time.
Bret Cahill
jobst....@stanfordalumni.org
>> Torch the end and shake off the solder until only a small nib is
>> left.
> Don't. Brake cable is slightly elastic - so that it's very strong.
> Gear cable is more rigid - for precise shifting - but that makes it
> more brittle. It is dangerous to use gear cable for brakes, and
> brake cable is too stretchy for gears.
Oh! Explain how that can be so, considering they are both steel and
the brake cable has a larger cross section. This is a tale I haven't
heard yet although there is a difference between brake cable housing
and shift cable STI housing.
http://www.sheldonbrown.com/brandt/sis-cable.html
Jobst Brandt
carl...@comcast.net
Dear Jobst,
Why take such needless offense, snarl, sneer, and make new enemies?
Why not just explain that the cables are the same material, but that
the cable housings are different and refer him to your far more
pleasant article?
Cheers,
Carl Fogel
ligh...@gmail.com
Mr. Brandt,
Can you clarify why if both SIS (shift) and SLR (brake) housings no
not compress, only SIS is recommended for the shifter? Your article
states that the SLR housing would change length when bent, but in the
case of indexed down-tube shifters (for which it was initially
developed) the only housing is at the back leading into the rear D.
But once the housing is installed, it does not turn or move so that
the length would then remain constant. (The same argument can be used
for the STI housing up front). I understood that the reason new
housing had to be develop was that the SLR housing would indeed
compress progressively with pressure, however minutely, so that
indexed shifting would not be reliable across the entire cassette.
Josh
carl...@comcast.net
Dear Josh,
Brake cable housing compresses a bit, but it's very strong, so it
works fine for the heavy loads of braking and your squeezing fingers
adjust for the slight compression.
That slight compression would goof up the much lighter, but more
sensitive loads involved in shifting.
So an almost compressionless cable was developed to allow accurate
shifting.
Paradoxically, the compressionless shift cable is weaker than brake
cable--too weak for the heavy load of braking.
So if you use stiff but weak shift cable housing for brakes, you run a
strong risk of the cable housing failing just when you need it most.
Basically, brake cable housing is wound tightly and its coils squish
together under a heavy load, staying in place and compressing a
little, while the shift cable housing is barely wound at all and can
bulge and split under a heavy load.
_____________________
/////////////////
///////////////// tightly wound brake cable
///////////////// each of the many coils compresses a bit
---------------------
/
one brake coil /
a single helix /
______________________
_
_ ' - . _
_ ' - . _ barely wound shifter cable
' - . _ much less compression
-----------------------
_
one shifter coil ' - .
a single turn every 100 mm
18 separate wires
Cheers,
Carl Fogel
jobst....@stanfordalumni.org
>> Simon Ceze writes:
>>>> Torch the end and shake off the solder until only a small nib is
>>>> left.
>>> Don't. Brake cable is slightly elastic - so that it's very
>>> strong. Gear cable is more rigid - for precise shifting - but
>>> that makes it more brittle. It is dangerous to use gear cable for
>>> brakes, and brake cable is too stretchy for gears.
>> Oh! Explain how that can be so, considering they are both steel
>> and the brake cable has a larger cross section. This is a tale I
>> haven't heard yet although there is a difference between brake
>> cable housing and shift cable STI housing.
http://www.sheldonbrown.com/brandt/sis-cable.html
> Why take such needless offense, snarl, sneer, and make new enemies?
Who should be offended when an anonymous poster under the guise of
"Simon says" gives much incorrect advice without flinching. Besides,
the FAQ item doesn't mention shift and brake cables, only housings. I
didn't notice calling the writer any rude names accusing him pf lying
or being stupid, as the peanut gallery does regularly and anonymously.
I notice they don't draw your attention to sensitivities.
> Why not just explain that the cables are the same material, but that
> the cable housings are different and refer him to your far more
> pleasant article?
What wasn't explained and is unpleasant about the words I wrote. They
directly address the claims made with no extras. Maybe you could
write a demonstration response to Simon's posting and show what you
feel is appropriate.
Jobst Brandt
jobst....@stanfordalumni.org
>>>> Torch the end and shake off the solder until only a small nib is
>>>> left.
>>> Don't. Brake cable is slightly elastic - so that it's very strong.
>>> Gear cable is more rigid - for precise shifting - but that makes it
>>> more brittle. It is dangerous to use gear cable for brakes, and
>>> brake cable is too stretchy for gears.
>> Oh! Explain how that can be so, considering they are both steel and
>> the brake cable has a larger cross section. This is a tale I haven't
>> heard yet although there is a difference between brake cable housing
>> and shift cable STI housing.
http://www.sheldonbrown.com/brandt/sis-cable.html
> Can you clarify why if both SIS (shift) and SLR (brake) housings do
> not compress, only SIS is recommended for the shifter? Your article
> states that the SLR housing would change length when bent, but in
> the case of indexed down-tube shifters (for which it was initially
> developed) the only housing is at the back leading into the rear D.
> But once the housing is installed, it does not turn or move so that
> the length would then remain constant. (The same argument can be
> used for the STI housing up front). I understood that the reason
> new housing had to be develop was that the SLR housing would indeed
> compress progressively with pressure, however minutely, so that
> indexed shifting would not be reliable across the entire cassette.
I'm unclear on the question, but the difference between shift housing
and brake housing is that SIS shift housing has strands lengthwise in
a long helix the way cables have, and brake housing is made of a stack
of rings (slightly helical). The centerline of brake housing becomes
longer when the housing is bent, it standing close packed on the
inside of the coils in the bend and having light between coils on the
outside.
Cable, on the other hand remains constant length because all its
strands pass though the inside AND outside of a bend. That is why it
must be helically wound.
With indexed shifting and shift cable making every bend the handlebars
make could cause a mis-shift or a jump out of gear. What the rear
derailleur does is immaterial because its cable housing doesn't move
while riding.
Jobst Brandt
carl...@comcast.net
Dear Jobst,
If you really have no idea how obnoxious and nasty you are to
strangers, then there isn't much hope for improvement, is there?
Cheers,
Carl Fogel
jobst....@stanfordalumni.org
>>>>> Torch the end and shake off the solder until only a small nib is
>>>>> left.
>>>> Don't. Brake cable is slightly elastic - so that it's very
>>>> strong. Gear cable is more rigid - for precise shifting - but
>>>> that makes it more brittle. It is dangerous to use gear cable
>>>> for brakes, and brake cable is too stretchy for gears.
>>> Oh! Explain how that can be so, considering they are both steel
>>> and the brake cable has a larger cross section. This is a tale I
>>> haven't heard yet although there is a difference between brake
>>> cable housing and shift cable STI housing.
http://www.sheldonbrown.com/brandt/sis-cable.html
>> Can you clarify why if both SIS (shift) and SLR (brake) housings do
>> not compress, only SIS is recommended for the shifter? Your
>> article states that the SLR housing would change length when bent,
>> but in the case of indexed down-tube shifters (for which it was
>> initially developed) the only housing is at the back leading into
>> the rear D. But once the housing is installed, it does not turn or
>> move so that the length would then remain constant. (The same
>> argument can be used for the STI housing up front). I understood
>> that the reason new housing had to be develop was that the SLR
>> housing would indeed compress progressively with pressure, however
>> minutely, so that indexed shifting would not be reliable across the
>> entire cassette.
> Brake cable housing compresses a bit, but it's very strong, so it
> works fine for the heavy loads of braking and your squeezing fingers
> adjust for the slight compression.
What do you mean "compresses a bit". In comparison to what?
> That slight compression would goof up the much lighter, but more
> sensitive loads involved in shifting.
I think you should re-read the FAQ item.
> So an almost compressionless cable was developed to allow accurate
> shifting.
It is not compressionless but rather constant length when being bent.
Brake housing is not constant length when being bent.
> Paradoxically, the compressionless shift cable is weaker than brake
> cable--too weak for the heavy load of braking.
Don't call it compressionless. Brake housing is less compression
prone under load than SIS shift housing which is "constant length"
housing.
You wrote this to test my endurance didn't you? Well you can say it
as you like but there are some who might take it seriously. As I
said, if you aren't joking, re-read the FAQ item.
Jobst Brandt
Bill Westphal
>>>>>>> Carl writes:
>
> Why take such needless offense, snarl, sneer, and make new enemies?
>
>>>>>>> to which Jobst replies
>
>> What wasn't explained and is unpleasant about the words I wrote.
>> They directly address the claims made with no extras. Maybe you
>> could write a demonstration response to Simon's posting and show
>> what you feel is appropriate.
>>
>> Jobst Brandt
- Oh! Explain how that can be so, considering they are both steel
- and the brake cable has a larger cross section. This is a tale I
- haven't heard yet although there is a difference between brake
- cable housing and shift cable STI housing.
- http://www.sheldonbrown.com/brandt/sis-cable.html
+ Not so! Consider that they are both steel and the brake cable has a
+ larger cross section. See my FAQ for a discussion of the differences
+ between brake cable housing and shift cable STI housing.
Phil, Non-Squid
> Torch the end and shake off the solder until only a small nib is left.
>
>
> Bret Cahill
Worked just fine with my mini butane torch just now. Slid onlyone-way into
4mm housing though. It would make for a good single-speeding setup, unless
you found a way to wallow out the housing so that it would allow the cable
to slide.
--
Phil
carl...@comcast.net
[snip]
>You wrote this to test my endurance didn't you?
[snip]
>Jobst Brandt
Dear Jobst,
Actually, you're not the center of RBT, much less the universe.
That's why you look so silly taking so many posts on the newsgroup
personally.
Cheers,
Carl Fogel
A Muzi
>> Torch the end and shake off the solder until only a small nib is left.
Phil, Non-Squid wrote:
> Worked just fine with my mini butane torch just now. Slid onlyone-way into
> 4mm housing though. It would make for a good single-speeding setup, unless
> you found a way to wallow out the housing so that it would allow the cable
> to slide.
What kind of derailleur do you use with a single speed gear cable?
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
G.T.
>> Bret Cahill wrote:
>>> Torch the end and shake off the solder until only a small nib is left.
>
> Phil, Non-Squid wrote:
>> Worked just fine with my mini butane torch just now. Slid onlyone-way
>> into 4mm housing though. It would make for a good single-speeding
>> setup, unless you found a way to wallow out the housing so that it
>> would allow the cable to slide.
>
> What kind of derailleur do you use with a single speed gear cable?
>
I assume he's talking about a simple SS conversion using the rear
derailer as a chain tensioner.
Greg
--
The ticketbastard Tax Tracker:
http://www.ticketmastersucks.org/tracker.html
Ron Hardin
The brake cables lasted longer on the stem shifters.
The matter is moot now with index twist grips, which seem never
to break the cable, though the (MRX) shifters themselves quickly
revert to friction shifters when the index thingy inside breaks off.
--
Ron Hardin
rhha...@mindspring.com
On the internet, nobody knows you're a jerk.
A Muzi
>>>> Torch the end and shake off the solder until only a small nib is left.
>> Phil, Non-Squid wrote:
>>> Worked just fine with my mini butane torch just now. Slid
>>> onlyone-way into 4mm housing though. It would make for a good
>>> single-speeding setup, unless you found a way to wallow out the
>>> housing so that it would allow the cable to slide.
> A Muzi wrote:
>> What kind of derailleur do you use with a single speed gear cable?
G.T. wrote:
> I assume he's talking about a simple SS conversion using the rear
> derailer as a chain tensioner.
I was just kidding but what does the cable do?
Phil, Non-Squid
>>>> Bret Cahill wrote:
>>>>> Torch the end and shake off the solder until only a small nib is
>>>>> left.
>
>>> Phil, Non-Squid wrote:
>>>> Worked just fine with my mini butane torch just now. Slid
>>>> onlyone-way into 4mm housing though. It would make for a good
>>>> single-speeding setup, unless you found a way to wallow out the
>>>> housing so that it would allow the cable to slide.
>
>> A Muzi wrote:
>>> What kind of derailleur do you use with a single speed gear cable?
>
> G.T. wrote:
>> I assume he's talking about a simple SS conversion using the rear
>> derailer as a chain tensioner.
>
> I was just kidding but what does the cable do?
Sorry... I didn't make it clear that I was referring to tensioning the cable
just enough to select not the smallest cogs, when limit screws aren't long
enough to do the trick. In other words, an emergency measure or one where
you're in an area where an appropriate cable cannot be had.
Let's say you're JRA in the boonies and your RD cable snaps at the head on a
Shimano STI, not uncommon. You take off your rear brake cable and politely
ask farmer Joe if he can heat up the head for you. You melt it off, route
it through to the RD, and clamp it down. You shift down a couple gears away
from the smallest cog and keep it there because housing friction prevents
you from upshifting again without manually pulling on the RD. You get back
home in a gear other than 42x12 and you can replace the cables then. How's
that?
Sometimes I use a 2-inch piece of derailleur cable to select a specific gear
on a SS with a full cassette as a temp measure. I don't do this with just
one cog b/c the spring tension is too weak to prevent bumps from
autoshifting onto the cassette body on the hub.
--
Phil
doug....@gmail.com
> On 5 Mar 2007 21:45:25 -0800, lighte...@gmail.com wrote:
>
> >Mr. Brandt,
>
> >Can you clarify why if both SIS (shift) and SLR (brake) housings no
> >not compress, only SIS is recommended for the shifter?
>
>
> Dear Josh,
>
> Brake cable housing compresses a bit, but it's very strong, ...
> <snip>
> Cheers,
>
> Carl Fogel
BAHAHAHAHAHAHAHA!!!!!!!!!!!!!!!!!!
LOL ... Carl, this guy -specifically- asked Jobst a question, and -
you- answered!!
Why on earth did you do that?
You must be way beyond green with envy!
Why not get your name legally changed to Jobst Brandt if you want to
be him so bad?
Cheers,
Doug
Ben C
> On Mar 5, 10:23 pm, carlfo...@comcast.net wrote:
>> On 5 Mar 2007 21:45:25 -0800, lighte...@gmail.com wrote:
>>
>> >Mr. Brandt,
>>
>> >Can you clarify why if both SIS (shift) and SLR (brake) housings no
>> >not compress, only SIS is recommended for the shifter?
>>
>> <snip>
>>
>> Dear Josh,
>>
>> Brake cable housing compresses a bit, but it's very strong, ...
>> <snip>
>> Cheers,
>>
>> Carl Fogel
>
> BAHAHAHAHAHAHAHA!!!!!!!!!!!!!!!!!!
>
> LOL ... Carl, this guy -specifically- asked Jobst a question, and -
> you- answered!!
>
> Why on earth did you do that?
People do that all the time. Damn, I just answered a question addressed
specifically to Carl Fogel. Now you will think that I want to be him.
doug....@gmail.com
> On 2007-03-06, doug.lan...@gmail.com <doug.lan...@gmail.com> wrote:
>
>
>
> > On Mar 5, 10:23 pm, carlfo...@comcast.net wrote:
> >> On 5 Mar 2007 21:45:25 -0800, lighte...@gmail.com wrote:
>
> >> >Mr. Brandt,
>
> >> >Can you clarify why if both SIS (shift) and SLR (brake) housings no
> >> >not compress, only SIS is recommended for the shifter?
>
> >> <snip>
>
> >> Dear Josh,
>
> >> Brake cable housing compresses a bit, but it's very strong, ...
> >> <snip>
> >> Cheers,
>
> >> Carl Fogel
>
> > BAHAHAHAHAHAHAHA!!!!!!!!!!!!!!!!!!
>
> > LOL ... Carl, this guy -specifically- asked Jobst a question, and -
> > you- answered!!
>
> > Why on earth did you do that?
>
> People do that all the time. Damn, I just answered a question addressed
> specifically to Carl Fogel. Now you will think that I want to be him.
The difference is you weren't racing Carl to be first :-)
Bret Cahill
The nibs don't seat well into the sockets.
> The brake cables lasted longer on the stem shifters.
> The matter is moot now with index twist grips, which seem never
> to break the cable, though the (MRX) shifters themselves quickly
> revert to friction shifters when the index thingy inside breaks off.
I resorted to this because every six months, almost like clockwork, my
chain ring deraileur cable would break. This wouldn't ordinarily be
an issue but my bike repair memory is only good for 5 months, 29 days.
I kept reinventing everything, _whether it needed it or not_.
For awhile I was splicing a brake cable onto a shifter cable with
fishing leader fittings which probably explains why my bike was never
stolen by the local meth heads.
Eventually I discovered I could go straight brake cable if I used a
grinder or torch.
Sunday, however, I splurged and got a Teflon coated brake cable which
seems to have solved the problem.
I'll be back in 5 months to let you know the results.
If not, Email BretC...@aol.com
Bret Cahill
Michael Press
<i59ru21hqnv6nk8te...@4ax.com>,
carl...@comcast.net wrote:
What you assert about cable and housing is not true.
What Jobst asserts is true. You are wrong. Jobst is
right. Nothing to do with who is the blessed one. You
treat this as a popularity contest. Learn to write
accurately about technical matters, and your entire
world view will be enhanced.
--
Michael Press
ligh...@gmail.com
OK, just so people don't keep explaining how both housings are made, I
know what you are all saying, as I've seen them both. In fact, at my
previous job, we used to supply the steel rod to make coiled (aka
brake) cable housing and my job was to perform failure analysis on our
customer's production defects.
Now, my point to Mr. Jobst was that, as Carl stated, I think the SIS
housing is indeed compressionless, or at least sufficiently
compression resistant for shifting purposes. I don't think it has
anything to do with "same length" issues. The rear derailler housing
loop does not change position (i.e. stays in the same location and
general shape) and so Mr J's point about length issue becomes moot.
What made indexed shifting poor with pre-SIS housing was the variation
in compression of the housing with different loads from the cable
tension resulting in inconsistent derailler index pull.
jobst....@stanfordalumni.org
http://www.sheldonbrown.com/brandt/sis-cable.html
> OK, just so people don't keep explaining how both housings are made,
> I know what you are all saying, as I've seen them both. In fact, at
> my previous job, we used to supply the steel rod to make coiled (aka
> brake) cable housing and my job was to perform failure analysis on
> our customer's production defects.
OK, so people won't keep repeating the compression story, please read
the FAQ item on the subject.
> Now, my point to Mr. Jobst (just because you have no name doesn't
> mean you should confuse my first and last name, and what's the "Mr."
> stuff about?) was that, as Carl stated, I think the SIS housing is
> indeed compressionless, or at least sufficiently compression
> resistant for shifting purposes. I don't think it has anything to
> do with "same length" issues. The rear derailler housing loop does
> not change position (i.e. stays in the same location and general
> shape) and so Mr J's point about length issue becomes moot. What
> made indexed shifting poor with pre-SIS housing was the variation in
> compression of the housing with different loads from the cable
> tension resulting in inconsistent derailler index pull.
Can you expand on that? How does brake cable housing compress? How
does SIS shift cable housing not compress? Do you understand how bake
cable path lengthens when its housing is bent and conversely why SIS
shift cable housing does not do that?
I mentioned that derailleur cable path does not change but that
because it is part of shift cable, the same housing is used as between
handlebar and bicycle frame. It is primarily MTB use where this comes
into play because when negotiation twisty little passages, large
steering excursions occur while pedaling and shifting. Road bicycles
are nearly always pointed straight ahead +- a few degrees of motion.
Jobst Brandt
carl...@comcast.net
[snip]
>Can you expand on that? How does brake cable housing compress? How
>does SIS shift cable housing not compress? Do you understand how brake
>cable path lengthens when its housing is bent and conversely why SIS
>shift cable housing does not do that?
[snip]
Dear Jobst,
We may just be arguing about terminology.
When a "path lengthens as its housing bends," it's reasonable to say
that the path compresses when the housing straightens and that the
housing effectively compresses.
Cheers,
Carl Fogel
jobst....@stanfordalumni.org
> [snip]
>> Can you expand on that? How does brake cable housing compress?
>> How does SIS shift cable housing not compress? Do you understand
>> how brake cable path lengthens when its housing is bent and
>> conversely why SIS shift cable housing does not do that?
> [snip]
> We may just be arguing about terminology.
...and we may not be doing so.
> When a "path lengthens as its housing bends," it's reasonable to say
> that the path compresses when the housing straightens and that the
> housing effectively compresses.
Scooter Libby had similar excuses for his "misstatements". You know
what "compress" means and you know what "constant length' means. The
term compressible was used to explain force transmission and position
transmission. This strikes me as the "this is not my native language"
defense.
Jobst Brandt
carl...@comcast.net
Dear Jobst,
I know that compression and shortening are commonly interchangeable.
If you want to quibble, feel free to argue that I'm Kim Jong-il.
Cheers,
Carl Fogel
Bob Flumere
>someone writes:
>
> http://www.sheldonbrown.com/brandt/sis-cable.html
>
The many reasons posted here are all valid, but:
The reason (as I understand it <G>) that SIS cable housing should not
be used for brake cable is that the forces involved in brake
application are much greater than the forces involved in shifting, and
that the SIS cable construction could allow it to "balloon" and
collapse under these forces.. The results would obviously be
unpleasant.
This cannot happen with the spherically wound brake housing under
compression.
My "Two Cents" <G>
Bob
p.k.
>>
> Dear Jobst,
>
> I know that compression and shortening are commonly interchangeable.
>
Only using very loose language!
If I hold a piece of stretched elastic by the ends, then move my hands
closer together, it has shortened but not compressed.
pk
Phil, Non-Squid
Spherically? I'd say it was more helically with one strand.
The problem that the non-Jobst side is failing to see is that Jobst is
claiming that SIS is *designed* to be constant length, even with no wire
tension: the path length does not change with a change in radius. It has
nothing to do with the tension on the wire.
Jobst claims that brake housing was *designed* to be strong under heavy wire
tension loads.
People are discussing what happens when the housing is used for the wrong
purpose, which is a completely separate issue from what the original design
goal was. Concerning that issue, Bob seemed to sum it up pretty well.
--
Phil
Bob Flumere
<REMOVEph...@hotmail.com> wrote:
>Bob Flumere wrote:
>> On 07 Mar 2007 18:51:05 GMT, jobst....@stanfordalumni.org wrote:
>>
>>> someone writes:
>>>
>>> http://www.sheldonbrown.com/brandt/sis-cable.html
>>>
>> The many reasons posted here are all valid, but:
>>
>> The reason (as I understand it <G>) that SIS cable housing should not
>> be used for brake cable is that the forces involved in brake
>> application are much greater than the forces involved in shifting, and
>> that the SIS cable construction could allow it to "balloon" and
>> collapse under these forces.. The results would obviously be
>> unpleasant.
>>
>> This cannot happen with the spherically wound brake housing under
>> compression.
>
>Spherically? I'd say it was more helically with one strand.
>
Sorry!
Wrong term.. <G> Helix not spherix...
Fingers not well connected to brain. (Maybe caused by a bulge in my
SIS cable housing) LOL
>The problem that the non-Jobst side is failing to see is that Jobst is
>claiming that SIS is *designed* to be constant length, even with no wire
>tension: the path length does not change with a change in radius. It has
>nothing to do with the tension on the wire.
>
>Jobst claims that brake housing was *designed* to be strong under heavy wire
>tension loads.
>
>People are discussing what happens when the housing is used for the wrong
>purpose, which is a completely separate issue from what the original design
>goal was. Concerning that issue, Bob seemed to sum it up pretty well.
Thanks very much!
Bob
Bill Sornson
> Scooter Libby had similar excuses for his "misstatements".
Yeah, he misremembered what he didn't do. Hang him!
doug....@gmail.com
doug....@gmail.com
>
>
>
> >Carl Fogel writes:
>
> >> [snip]
>
> >>> Can you expand on that? How does brake cable housing compress?
> >>> How does SIS shift cable housing not compress? Do you understand
> >>> how brake cable path lengthens when its housing is bent and
> >>> conversely why SIS shift cable housing does not do that?
>
> >> [snip]
>
> >> We may just be arguing about terminology.
>
> >...and we may not be doing so.
>
> >> When a "path lengthens as its housing bends," it's reasonable to say
> >> that the path compresses when the housing straightens and that the
> >> housing effectively compresses.
>
> >Scooter Libby had similar excuses for his "misstatements". You know
> >what "compress" means and you know what "constant length' means. The
> >term compressible was used to explain force transmission and position
> >transmission. This strikes me as the "this is not my native language"
> >defense.
>
> >Jobst Brandt
>
> Dear Jobst,
>
> I know that compression and shortening are commonly interchangeable.
Dear Carl,
Do you really want to be common? From Texas A&M we have:
"She was as common as owl shit."
"She's as common as pig tracks."
"He's so common his piss won't foam."
And my favorite:
"He was trembling like a dog shitting a log-chain and dreading the
hook."
Raise your sights a bit!
Doug
ligh...@gmail.com
Just to be safe, I re-read your article.
Let me ask from a different perspective. Why did Shimano develop SIS
housing back in the days of down-tube indexed shifting if what you say
is correct?:
"SIS ® housing has no benefit for downtube attached shifters because
the cable bends do not change."
jobst....@stanfordalumni.org
http://www.sheldonbrown.com/brandt/sis-cable.html
> Let me ask from a different perspective. Why did Shimano develop
> SIS housing back in the days of down-tube indexed shifting if what
> you say is correct?:
> "SIS ® housing has no benefit for downtube attached shifters because
> the cable bends do not change."
I have no idea when it was introduced and whether any on-handlebar
shifting was available. The reason for the cable housing is to
prevent length change while bending. It is specifically for shift
cables, not being strong enough to be safely used for brake cables.
If you understand the difference between the two kinds of housings, it
should be apparent what the SIS design goal is.
Jobst Brandt
Bad Idea
UberHerrdoktorprofessor Jobst Brandt wrote:
>
> Can you expand on that? How does brake cable housing compress?
How
> does SIS shift cable housing not compress? Do you understand
how...
Is it similar to the way spokes compress?
Gary Young
<snip>
>
> Just to be safe, I re-read your article.
>
> Let me ask from a different perspective. Why did Shimano develop SIS
> housing back in the days of down-tube indexed shifting if what you say
> is correct?:
> "SIS ® housing has no benefit for downtube attached shifters because the
> cable bends do not change."
Weren't mountain bikes using thumb shifters and twist shifters long
before road bikes made the move to brifters? Maybe SIS housing was
introduced when it was because it was important to mountain bikes. It
would also be important to tourists and triathletes using bar-end
shifters. You may be blinkered by thinking exclusively about road bikes.
jobst....@stanfordalumni.org
As I mentioned, road bicycles have little need for SIS cable housing
because their bars remain nearly straight ahead during all riding
while MTB riding through twisty little passages in tangly thickets
make large steering excursions while pedaling and shifting. I suspect
the impetus cam from MTB use, but I don't know.
Jobst Brandt
A Muzi
>> someone writes:
>> Can you expand on that? How does brake cable housing compress? How
>> does SIS shift cable housing not compress? Do you understand how bake
>> cable path lengthens when its housing is bent and conversely why SIS
>> shift cable housing does not do that?
> jobst.bra...@stanfordalumni.org wrote:
>> I mentioned that derailleur cable path does not change but that
>> because it is part of shift cable, the same housing is used as between
>> handlebar and bicycle frame. It is primarily MTB use where this comes
>> into play because when negotiation twisty little passages, large
>> steering excursions occur while pedaling and shifting. Road bicycles
>> are nearly always pointed straight ahead +- a few degrees of motion.
ligh...@gmail.com wrote:
> Just to be safe, I re-read your article.
> Let me ask from a different perspective. Why did Shimano develop SIS
> housing back in the days of down-tube indexed shifting if what you say
> is correct?:
> "SIS ® housing has no benefit for downtube attached shifters because
> the cable bends do not change."
Original New DuraAce SIS, then New 600 SIS and then Sante-7 SIS and all
their competitors used spiral casing. The advent of both cheap "city
bike" indexed top shifters and the popularity of offroad models
necessitated 'longitudinally stranded' or 'high-helix' or 'index' or
'compressionless' casing along with better wire finish. Somewhere around
1987? 1988? Before 1991/92 road integrated levers anyway