Indexed front changer woes

citizen142 said:

Pal has given me a boxed mountain bike to put together. No real
problems until it came to getting the front triple changer to work.
They are indexed handlebar mounted twist changers. How the hell do you
adjust them? Ok position 1 and 3 to some extent by adjusting the stops
on the front changer but position two? The solution I arrived at was
to put the twist grip into 2 position with the cage at centre of the
middle ring by wedging something against the frame and cage so it
could not move and then drawing the cable tight with a pair of pliers
and tightening the 9 mm cable bolt. This worked of a fashion - but
because the rear block is a 7 indexed it does not work when in top or
bottom cogs! On a friction lever operated system one merely adjusts
for this with the lever but how the hell do you do this on index? Can
it ever work properly?

Is the cable completely slack when in the smallest front ring?

I have found that if you have some tension in the cable in all
positions, and adjust for the inner and outer rings with the limit
screw, then the middle ring works out about right.

But if it's scraping on the front mech in the middle ring in both the
top and bottom rear cogs then there's no solution other than avoid using
those gears, unless the shifter has some kind of "trim" facility.

citizen142 said:

Pal has given me a boxed mountain bike to put together. No real
problems until it came to getting the front triple changer to work.
They are indexed handlebar mounted twist changers. How the hell do you
adjust them? Ok position 1 and 3 to some extent by adjusting the stops
on the front changer but position two? The solution I arrived at was
to put the twist grip into 2 position with the cage at centre of the
middle ring by wedging something against the frame and cage so it
could not move and then drawing the cable tight with a pair of pliers
and tightening the 9 mm cable bolt. This worked of a fashion - but
because the rear block is a 7 indexed it does not work when in top or
bottom cogs!

On a friction lever operated system one merely adjusts
for this with the lever but how the hell do you do this on index? Can
it ever work properly?

Is there a front cable adjuster? If not, could one be fitted?

~PB

"citizen142" <[email hidden]> wrote in news:SJ6lh.5331
[email hidden]:

Quoted message said:

They are indexed handlebar mounted twist changers. How the hell do you
adjust them?

Hopefully, Sheldon Brown's page on Derailer Adjustment can help:

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

On 29/12/2006 11:11, citizen142 said,

Quoted message said:

Pal has given me a boxed mountain bike to put together. No real
problems until it came to getting the front triple changer to work.
They are indexed handlebar mounted twist changers. How the hell do you
adjust them?

Have you checked the manufacturer's website to see if there are
downloadable instruction sheets? Shimano are quite good at that, for
instance.

--
Paul Boyd
http://www.paul-boyd.co.uk/

In article <[email hidden]>

citizen142 said:

Pal has given me a boxed mountain bike to put together. No real
problems until it came to getting the front triple changer to work.
They are indexed handlebar mounted twist changers. How the hell do you
adjust them? Ok position 1 and 3 to some extent by adjusting the stops
on the front changer but position two? The solution I arrived at was
to put the twist grip into 2 position with the cage at centre of the
middle ring by wedging something against the frame and cage so it
could not move and then drawing the cable tight with a pair of pliers
and tightening the 9 mm cable bolt. This worked of a fashion - but
because the rear block is a 7 indexed it does not work when in top or
bottom cogs!

Sounds like you've got the adjustment right, although I'm surprised
there isn't a cable adjuster on the shifter. As long as it's shifting
cleanly with the chain in the middle of the block there's not much more
you can do.

citizen142 said:

Pal has given me a boxed mountain bike to put together. No real
problems until it came to getting the front triple changer to work.
They are indexed handlebar mounted twist changers. How the hell do you
adjust them? Ok position 1 and 3 to some extent by adjusting the stops
on the front changer but position two? The solution I arrived at was
to put the twist grip into 2 position with the cage at centre of the
middle ring by wedging something against the frame and cage so it
could not move and then drawing the cable tight with a pair of pliers
and tightening the 9 mm cable bolt. This worked of a fashion - but
because the rear block is a 7 indexed it does not work when in top or
bottom cogs! On a friction lever operated system one merely adjusts
for this with the lever but how the hell do you do this on index? Can
it ever work properly?

Can't say I follow exactly what the problem is that your having, but
as I found out recently when installing new shifters, if the cable does
not follow the exact correct route to reach the anchor bolt the
resulting parallelogram shape of the mechanism may be distorted and
will never shift correctly.