Front derailleur adjustment Woes and Suspension

[[email protected]]

I have just acquired dual suspension mountain bike circa late 90's It
has a shimano SIS system.

The person who owned the bike before me hardly ever used it, so its
been stood up for a few years

I have adjusted the front derailleur on the bike, and it works when
the back wheel is in the air (Although the index shifting is out)

As soon as I ride the bike, I get problems with down shifting, the
bike will take ages to down shift to the small inside cog on the
front. The cable seems responsive i.e as soon as I move the shifter
the front derailleur moves.

I suspect the front derailleur does not even move to the low limit
screws. In fact I can remove the low limit screw and the chain does
not fall off.

Also more of the same between the outside cog to the middle.

Any ideas on how to fix this ?


Also, My rear suspension has a shock with no external spring, and no
air inlet (I guess its an old system, not sure how it works though) I
have three vertical mounting holes on the bottom shock bolt, what does
this adjust, and which hole should it mounted in?

 

[Lou Holtman]

[email protected] wrote:
> I have just acquired dual suspension mountain bike circa late 90's It
> has a shimano SIS system.
>
> The person who owned the bike before me hardly ever used it, so its
> been stood up for a few years
>
> I have adjusted the front derailleur on the bike, and it works when
> the back wheel is in the air (Although the index shifting is out)
>
> As soon as I ride the bike, I get problems with down shifting, the
> bike will take ages to down shift to the small inside cog on the
> front. The cable seems responsive i.e as soon as I move the shifter
> the front derailleur moves.
>
> I suspect the front derailleur does not even move to the low limit
> screws. In fact I can remove the low limit screw and the chain does
> not fall off.
>
> Also more of the same between the outside cog to the middle.
>
> Any ideas on how to fix this ?


I would do this:

detach cable from FD and look if the FD reaches the limit screw,
check if the cable moves freely,
clean/lube/replace cable,
align FD in height and angle,
start adjust FD from scratch.

Lou
--
Posted by news://news.nb.nu (http://www.nb.nu)

 

[M-gineering]

[email protected] wrote:
> I have just acquired dual suspension mountain bike circa late 90's It
> has a shimano SIS system.
>
> The person who owned the bike before me hardly ever used it, so its
> been stood up for a few years
>
> I have adjusted the front derailleur on the bike, and it works when
> the back wheel is in the air (Although the index shifting is out)
>
> As soon as I ride the bike, I get problems with down shifting, the
> bike will take ages to down shift to the small inside cog on the
> front. The cable seems responsive i.e as soon as I move the shifter
> the front derailleur moves.
>
> I suspect the front derailleur does not even move to the low limit
> screws. In fact I can remove the low limit screw and the chain does
> not fall off.
>
> Also more of the same between the outside cog to the middle.
>
> Any ideas on how to fix this ?
>
>
> Also, My rear suspension has a shock with no external spring, and no
> air inlet (I guess its an old system, not sure how it works though) I
> have three vertical mounting holes on the bottom shock bolt, what does
> this adjust, and which hole should it mounted in?
>

Dual suspension, SIS, hardly ever used. Are these clues? Is it a ukp79
special? Be prepared for a mismatch of **** parts which will never work
--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

 

[Qui si parla Campagnolo]

On Feb 19, 3:14 am, "[email protected]" <[email protected]> wrote:
> I have just acquired dual suspension mountain bike circa late 90's It
> has a shimano SIS system.
>
> The person who owned the bike before me hardly ever used it, so its
> been stood up for a few years
>
> I have adjusted the front derailleur on the bike, and it works when
> the back wheel is in the air (Although the index shifting is out)
>
> As soon as I ride the bike, I get problems with down shifting, the
> bike will take ages to down shift to the small inside cog on the
> front. The cable seems responsive i.e as soon as I move the shifter
> the front derailleur moves.
>
> I suspect the front derailleur does not even move to the low limit
> screws. In fact I can remove the low limit screw and the chain does
> not fall off.
>
> Also more of the same between the outside cog to the middle.
>
> Any ideas on how to fix this ?

Longer BB spindle if possible. Probably the FD is hitting the frame
before it can move the chain to the small ring. Common i this era FS
MTBs.
>
> Also, My rear suspension has a shock with no external spring, and no
> air inlet (I guess its an old system, not sure how it works though) I
> have three vertical mounting holes on the bottom shock bolt, what does
> this adjust, and which hole should it mounted in?

??? Middle one?

 

[[email protected]]

On Feb 19, 11:50 am, Lou Holtman <[email protected]> wrote:

> I would do this:
>
> detach cable from FD and look if the FD reaches the limit screw,
> check if the cable moves freely,
> clean/lube/replace cable,
> align FD in height and angle,
> start adjust FD from scratch.


Thanks, it was the cable as soon as I loosened the cable on the FD the
FD went to the low limit, so re-attached the cable, and is now fine on
downshifting.

Upshifting does needs to go beyond the index still though (then
release back to the index), I have tried adjusting the index barrel on
the shifter, but doesn't seem to do anything.