STI Cable Issues

Dion Dock said:

I have broken 2-3 with my 8 speed shifters and my wife has done the same
with her 9 speed shifters. Typically, the shifting gets worse and adjusting
the cable tension won't fix it. Then, one day you shift into your 21 and
*bang* the head snaps off the cable inside the shifter.

Exactly. But now that I know I switch the cable as soon as it starts
needing adjusting -- that's a sign that the cable is fraying.

JT

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In article <[email hidden]>, John Verheul

Quoted message said:

I have no personal experience with STI shifters, but I know several people
who report breaking a rear der cable with some regularity (less than every
10,000 miles). Is there an inherent flaw with STI shifters (these are all
D/A 9s) with respect to the lifespan of the cables, or is there perhaps some
user error involved?

John Verheul

John,

Cable breakage is really not inherent specifically to STI shifters.
Bar ends and Campy Ergos suffer the same fate -- I know as I own them
all (STI/Bar ends and Ergos Mirage and Daytona). Basically, they break
either due to fatigue (repetitive shifting), poor maintenance and
installation and or cable pinching by using the wrong cable (this being
only to Campy ergo shifters using Shimano cables with a slight bigger
head).

Cables are made of steel and they do have a finite fatigue lifespan,
which means they don't last forever and ever. Since cables are
relatively cheap, replacing them is not a financial issue.

Many cyclists do not maintain their bikes very well. Fraying and
rusting cables are not good signs of adequate maintenance. Also, when
installing these cables, did the mechanic apply a decent amount of
Philwood tenacious oil on them before inserting them into the housing??
A suprisingly high number of mechanics I notice in shops "DO NOT" do
this -- they just install bare cables right into the housing.
Likewise, a suprisingly high number of home mechanics do not do this
either, fearing the it messes up with their beautiful fingers.
Oiling the cables is an added preventive measure against rust.

Using the wrong cable for the shifters can also be blamed by premature
cable breakage, usually at the head of the cable. It's by people who
used Shimano type brake cable on Campy Ergo style shifters. The cable
head does not fit correctly into the slot of the shifter's brake lever.
So, they won't fit nicely into the recessed hole. I knew some people
actually filed the head to fit -- hope they didn't file the cable with
it. It's appalling to see people riding with the head sticking out and
being forcely pinched because the brake lever does not flush properly
into the hood. End result, cable breakage and these people blame poor
Ergo design and champion STI brifters superior performance. Not until
I made them aware that they used the wrong cable that they realized
their own mistake.. People can make mistakes installing cables, but
it's easy to blame directly on something rather on themselves.

David.

In article said:

In article <[email hidden]>,

John Verheul said:

I have no personal experience with STI shifters, but I know several people
who report breaking a rear der cable with some regularity (less than every
10,000 miles). Is there an inherent flaw with STI shifters (these are all
D/A 9s) with respect to the lifespan of the cables, or is there perhaps some
user error involved?

I have seen a couple of cases where the cable broke at the head
(inside the shifter), apparently because of a problem with this design.
10,000 miles isn't bad, though. Most bike repair manuals recommend
replacing cables annualy.

I've also seen cables brake at the pinch bolt, most likely due to user
error (pinching too tight).

Breaking at the head can usually be caused by using the wrong cable for
the shifters in question and not a design issue. I live in a mainly
predominant Shimano town, so it's not too uncommon for an inexperienced
Campy rider to buy the wrong cable rebuild kit or have a Shimano
mechanic install the wrong ones or even file them on the head so they
will fit into the slot. It's appalling to see that people still ride
with cable head sticking slightly out of their Campy shifters, which
not only compromises on its performance but also a safety issue..

I usually deter people from buying a generic shifter/brake cable
rebuilt kit simply because, it's generic. And yet, people like to
skimp on a few bucks on good proper cables, which in themselves are
affordable already!! When they break, they blame it all on the
shifters.

Talk about passing the buck.

David.

Quoted message said:

a Shimano mechanic ... file them on the
head so they will fit into the slot.

What's the problem with this?

--
Phil, Squid-in-Training

Quoted message said:

Many cyclists do not maintain their bikes very well. Fraying and
rusting cables are not good signs of adequate maintenance. Also, when
installing these cables, did the mechanic apply a decent amount of
Philwood tenacious oil on them before inserting them into the
housing?? A suprisingly high number of mechanics I notice in shops
"DO NOT" do this -- they just install bare cables right into the
housing. Likewise, a suprisingly high number of home mechanics do not
do this either, fearing the it messes up with their beautiful fingers.
Oiling the cables is an added preventive measure against rust.

From http://www.sheldonbrown.com/derailer-adjustment.html:

" With modern, lined housing, greasing the cables is no longer necessary. In
fact, it makes things worse, due to the stickieness of the grease."

I never lube new cables in new housing. Old cables in old housing, new
cables in old housing, or old cables in new housing (none of which should
ever be done, but customers are stingy) means that I lube either or both.

--
Phil, Squid-in-Training

Phil said:

Quoted message said:

a Shimano mechanic ... file them on the
head so they will fit into the slot.

What's the problem with this?

--
Phil, Squid-in-Training

If done well, no problem. Filing sometimes doesn't make the head small
enough or encourages broken strands(poor filing or grinding nicking the
cable itself)...using the proper cable is the key. Using a Campag one
for shimano is no big deal. We use Torelli wires.

In article <CGwbf.1624$6C.19@dukeread02>, Phil, Squid-in-Training

Quoted message said:

Quoted message said:

a Shimano mechanic ... file them on the
head so they will fit into the slot.

What's the problem with this?

If done properly by an experienced mechanic, then there's no problem.
Unfortunately, many shops these days hire very young, inexpensive and
highly inexperienced mechanics that have questionable quality assurance
practice. Consumers tend to be stingy when it comes to bike
maintenance and always go for the lowest cost possible. I am sure some
people here who own bike shops had seen some very shoddy workmanship
performed by some other bike shops. That is the problem..

David.

Squid-in-Training said:

I never lube new cables in new housing. Old cables in old housing, new
cables in old housing, or old cables in new housing (none of which should
ever be done, but customers are stingy) means that I lube either or both.

Do you mean new and old as in traditional unlined versus modern lined?
Cause with normal meanings of new and old, new cables in old housing makes
sense, especially if the cable's just worn through somewhere. Replacing
housing can be difficult on some bikes.

Jasper

Jasper Janssen said:

Squid-in-Training said:

I never lube new cables in new housing. Old cables in old housing,
new cables in old housing, or old cables in new housing (none of
which should ever be done, but customers are stingy) means that I
lube either or both.

Do you mean new and old as in traditional unlined versus modern lined?
Cause with normal meanings of new and old, new cables in old housing
makes sense, especially if the cable's just worn through somewhere.
Replacing housing can be difficult on some bikes.

I meant new and old as in new from the box and old still on the bike. In
other words, Walmart bike owners who break their cables are never willing to
pay for new housing if it's not absolutely necessary. In those cases, I
lube the existing housing.

I haven't seen unlined housing on anything except the really really cheap
housing from Nashbar, and old bikes. Come to think of it, I haven't really
seen unlined housing on late-model Walmart bikes, either.

--
Phil, Squid-in-Training

Hay Phil

Do you think that Teflon coated cables are worth the extra bucks? I
just installed "aero" brake levers in place of 2 old "not aero" levers,
along w/ new housing & cables. Used hi quality lined Jagwire brake
housing for fr. & rr. For the fr. I installed a drawn stainless steel
non-coated cable. The rr. I discovered didn't have any uncoated road
cables, so I used a Teflon coated one I happened to have. I've always
doubted that coated cables were worth the price over drawn S.S. cables
in lined housings. But I have to admit that the rear brake is smoother
that the front, even though it is 2' longer. I may have to rethink
this.
As to oil or not to oil, I always blow aerosol Tri Flo through the
housing, from both ends. Not so much for the lube but to remove debris
left inside from filling and grinding the ends square & deburing them.
If I had an air compressor, I might not lube them.

Opinions, thoughts, comments.
Thanks, John

john said:

Hay Phil

Do you think that Teflon coated cables are worth the extra bucks? I
just installed "aero" brake levers in place of 2 old "not aero"
levers, along w/ new housing & cables. Used hi quality lined Jagwire
brake housing for fr. & rr. For the fr. I installed a drawn stainless
steel non-coated cable. The rr. I discovered didn't have any uncoated
road cables, so I used a Teflon coated one I happened to have. I've
always doubted that coated cables were worth the price over drawn
S.S. cables in lined housings. But I have to admit that the rear
brake is smoother that the front, even though it is 2' longer. I may
have to rethink this.
As to oil or not to oil, I always blow aerosol Tri Flo through the
housing, from both ends. Not so much for the lube but to remove debris
left inside from filling and grinding the ends square & deburing them.
If I had an air compressor, I might not lube them.

Opinions, thoughts, comments.
Thanks, John

I haven't had any experience with Teflon cables. IME, the bends of the
housing at the handlebars exert more drag than anything other factor. Does
your housing on the left and right sides take similar bends? Or does the
rear housing have a straighter path? (not likely). You seem to know what
you're doing. It looks like your Teflon cable is another data point we'll
take into consideration.

Cost-wise, if it's worth the extra couple bucks, then maybe the Teflon would
be a good idea after all, if you don't like to do as much maintenance.

The debris thing you mentioned usually isn't an issue when I grind the
housing down on my bikes, I think because the liner smushes up, sealing out
steel filings during the grinding process. Maybe so, maybe no, I dunno!

--
Phil, Squid-in-Training

Teflon coated cables do not last long. Teflon is a great friction reducer but the coating is rapidly worn away, leaving the bare steel to corrode. Oil only hurts because it attracts dirt, causing the coating to wear faster.

I have NEVER broke a shifter cable when using stainless steel that came with the original shifters. I found on replacing my 1998 era 9 speed DA that the original cables had started to corrode (stainless is actually only corrosion resistant) and might have not made it another season...but 6 years is quite impressive compared to the old zinc coated carbon steel of yesteryear.

Yes, steel can fatigue BUT it does have a finite limit, beyond which it will last forever. This is well-known in the wire rope industry and applications like elevators NEVER place the wire at radii smaller than the manufacturer's minimum bend radius. Such is probably the case in STI/Ergo shifters although I do not know this to be fact. It "looks" right to me in most cases.

Who brough up mileage? That is about as arbitrary a measure of shifter use as PowerBar consumption. The fact should be root cause analysis. If the break looks like a '73 Cutlass in Detroit, chances are fatigue isn't the cause. Sure, there WILL be broken strands BUT fatigue didn't cause this failure.

FWIW, I have most problems with housing corrosion. I use Nokon's for this purpose since they seem to be a better match with my aluminum frame.

Weisse Luft said:

Who brough up mileage? That is about as arbitrary a measure of shifter
use as PowerBar consumption.

What do you suggest as a better metric?

--
Dave
dvt at psu dot edu

Ya Know, Phil

I never thought of that. I always open up the liner before I start
grinding. And then again slightly after grinding. From now on, I'm
going to not open them up until after grinding.
Good thinking, Phil

John