rear derailer only indexing to 3 gears, front to 1



Greetings and thank you for taking the time to read this

I've read Sheldon's guide to derailer adjustment, searched the this
google group and a few other sites on the web and worked on this bike
for hours with no progress. I'm no bike tech guru but I can usually
figure mechanical things out fairly easy and have had no luck with
this, so I figure it must be something fairly simple :).

I'm attempting to repair my fathers 90's era Giant Rincon 21 speed with
push button selectors. Last time i took it out it I could only use the
2nd front gear and the middle 3 rear gears.

When I readjusted the rear derailer starting with the highest gear it
would still only select the three highest gears. The derailer would
move all the way to the lowest when i push the selector but upon
releasing it always moves back down the the third highest gear. I
readjusted the derailer so I could select the lowest gear, but still,
only three gears.

I adjusted the b-tension adjuster -no luck.
I am sure that the high and low limit stops are properly adjusted.
Neither the derailer nor any of its parts seem bent to me nor does it
appear to have taken any hard knocks and my father does not remember
any chrashes with the bike.

Any advice greatly appreciated :)
 
J

Jeff Starr

Guest
On 7 Sep 2006 18:43:38 -0700, [email protected] wrote:

>Greetings and thank you for taking the time to read this
>
>I've read Sheldon's guide to derailer adjustment, searched the this
>google group and a few other sites on the web and worked on this bike
>for hours with no progress. I'm no bike tech guru but I can usually
>figure mechanical things out fairly easy and have had no luck with
>this, so I figure it must be something fairly simple :).
>
>I'm attempting to repair my fathers 90's era Giant Rincon 21 speed with
>push button selectors. Last time i took it out it I could only use the
>2nd front gear and the middle 3 rear gears.
>
>When I readjusted the rear derailer starting with the highest gear it
>would still only select the three highest gears. The derailer would
>move all the way to the lowest when i push the selector but upon
>releasing it always moves back down the the third highest gear. I
>readjusted the derailer so I could select the lowest gear, but still,
>only three gears.
>
>I adjusted the b-tension adjuster -no luck.
>I am sure that the high and low limit stops are properly adjusted.
>Neither the derailer nor any of its parts seem bent to me nor does it
>appear to have taken any hard knocks and my father does not remember
>any chrashes with the bike.
>
>Any advice greatly appreciated :)


Hi, if it was working in the past, you shouldn't have needed to make
any limit stop or B-tension adjustments. Generally, the only thing
that needs fine tuning is cable tension.

I'm not familiar with your shifters, but I can tell you this, your
problems are either cable or shifter related, not the derailleurs.

We have all done it, or most of us have. We have thought that if it
isn't shifting correctly, it must be the derailleurs. And then have
proceeded to screw up the correct adjustments.

Unless someone familiar with the shifters tells you something more
helpful, I would replace the inner cables. They are not expensive, and
may solve your problems. Either way, it can't hurt, and may help.

Or take it to your LBS, there is another option.


Life is Good!
Jeff
 
W

Werehatrack

Guest
On 7 Sep 2006 18:43:38 -0700, [email protected] wrote:

>Greetings and thank you for taking the time to read this
>
>I've read Sheldon's guide to derailer adjustment, searched the this
>google group and a few other sites on the web and worked on this bike
>for hours with no progress. I'm no bike tech guru but I can usually
>figure mechanical things out fairly easy and have had no luck with
>this, so I figure it must be something fairly simple :).
>
>I'm attempting to repair my fathers 90's era Giant Rincon 21 speed with
>push button selectors. Last time i took it out it I could only use the
>2nd front gear and the middle 3 rear gears.
>
>When I readjusted the rear derailer starting with the highest gear it
>would still only select the three highest gears. The derailer would
>move all the way to the lowest when i push the selector but upon
>releasing it always moves back down the the third highest gear. I
>readjusted the derailer so I could select the lowest gear, but still,
>only three gears.
>
>I adjusted the b-tension adjuster -no luck.
>I am sure that the high and low limit stops are properly adjusted.
>Neither the derailer nor any of its parts seem bent to me nor does it
>appear to have taken any hard knocks and my father does not remember
>any chrashes with the bike.
>
>Any advice greatly appreciated :)


Two possibilities come to mind; the cable may be corroded or crudded
up internally, or the shifter's possibly crudded up with congealed
grease, and either way the crud or corrosion is not allowing the cable
to move beyond a certain point under just the der's spring tension.
I'd pull the cable, inspect it, reinstall if it's clean and
free-moving, and then flush the shifter with a solvent-based lube
spray like WD40, work it until it frees up, let it dry and then lube
with a decent oil. If I had to take a guess, I'd expect to find that
the rear der was left in the third gear slot when the bike was parked
long ago, and the cable's not moving beyond that point.

The same scenario probably applies to the front, although there I
suspect that the cable's probably just not moving the der at all.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
J

JeffWills

Guest
Werehatrack wrote:
>
> Two possibilities come to mind; the cable may be corroded or crudded
> up internally, or the shifter's possibly crudded up with congealed
> grease, and either way the crud or corrosion is not allowing the cable
> to move beyond a certain point under just the der's spring tension.
> I'd pull the cable, inspect it, reinstall if it's clean and
> free-moving, and then flush the shifter with a solvent-based lube
> spray like WD40, work it until it frees up, let it dry and then lube
> with a decent oil. If I had to take a guess, I'd expect to find that
> the rear der was left in the third gear slot when the bike was parked
> long ago, and the cable's not moving beyond that point.
>
> The same scenario probably applies to the front, although there I
> suspect that the cable's probably just not moving the der at all.


I'd agree with the 'hatrack. I have a set of elderly XTR shifters which
started behaving erratically while on tour. A couple squirts of spray
oil restored their function in a jiffy.

Replacing the cables, squirting a little oil through the housing, and
flushing the internals of the shifters will probably do wonders.

Jeff