7-speed Positron cable housing broken

"Jussi Mantere" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Hi all,

Wonder if anyone could help me with this one? I'm trying to get the old touring bike of my
girlfriend fixed. The gears stopped working, and after a bit of analysis I found out that a) it's
using a 7-speed Positron system (single-cable), and b) the cable housing is broken in one part, so
that c) whenever one tries to shift one gear up, the cable, instead of pushing the derailleur,
pushes itself out of the hole.

So, my question(s) are:
a) Is it possible to get a new housing for the cable anywhere these days?
b) How on earth does one even replace the housing? I managed to get the cable removed from the
shifter, but found no way to disconnect it from the derailleur?
c) If the answer for either a or b is negative, would it be possible to replace the system with a
SIS (or whatever) alternative?

The bike itself is in quite a nice condition, although a bit over 10 years old, so it'd be nicer
just to fix the gears instead of getting a new bike

🙂

Quoted message said:

Thanks,
-j

--
. jussi mantere

They MADE a 7speed Positron system?!?! That was optimistic....I don't know if you can get
replacement cable or housings. I think any housing would do, the main difference as far as I can
remember being the inner cable was solid. It's possible (this is some time ago..the wheels are
creaking....) that there was a ferrule on BOTH ends? In that case you'd have to replace the whole
cable, inner and outer, as one, or perhaps fudge something so that you could use a pinch bolt.

You can update to a newer system for sure, but I don't know if it's worth the cost. You'd likely
need a rear derailleur, shifters, cables and possibly a cassette (not sure if Positron cassettes are
the same as SIS cassettes..there is a good chance they are interchangeable I'd guess). You could be
looking at $50-$100. You might be able to get some used stuff (7sp is not that popular anymore) and
save some dough. Also, you might have problems withc cable stops (or lack thereof) if you switch to
SIS. I think Positron had a complete housing, front to back.

Good Luck,

Scott..

"Jussi Mantere" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Hi all,

Wonder if anyone could help me with this one? I'm trying to get the old touring bike of my
girlfriend fixed. The gears stopped working, and after a bit of analysis I found out that a) it's
using a 7-speed Positron system (single-cable), and b) the cable housing is broken in one part, so
that c) whenever one tries to shift one gear up, the cable, instead of pushing the derailleur,
pushes itself out of the hole.

So, my question(s) are:
a) Is it possible to get a new housing for the cable anywhere these days?
b) How on earth does one even replace the housing? I managed to get the cable removed from the
shifter, but found no way to disconnect it from the derailleur?
c) If the answer for either a or b is negative, would it be possible to replace the system with a
SIS (or whatever) alternative?

The bike itself is in quite a nice condition, although a bit over 10 years old, so it'd be nicer
just to fix the gears instead of getting a new bike

🙂

On some Positron systems it is possible to: cut the wire at the very end, throw away the original
square mounting tab, remove the wire from the casing, change the casing, lubricate the wire,
reinstall in a slightly shorter casing and fabricate an anchor assembly for the gear changer. I have
done this a few dozen times, under duress, so I know it is possible, albeit not much fun.

The difficult part is getting the plastic end caps of the casing to lock firmly to both the casing
and their steel stops. They are often damaged.
--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

Shimano made a SEVEN speed Positron?

As recently as 10 years ago?

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": geocities.comczcornerOpen ↗