How Is Indexing Attained?

"etaoin shrdlu" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

How is indexing in the rear attained? The front I don't care about. Is it the combination of

- shifter & derailleur
- shifter & cluster (freewheel / cassette)
- derailleur & cluster
- shifter, derailleur, & cluster
- none of the above
- occurs only during a syzygy of three or more planets

I'm rehabbing a couple of bikes & wondering about how best to put components from different
manufacturers together (mainly SunTour & Shimano)

SunTour's AccuShift indexing system has more space between the cogs on the high end of the range
than at the low end. The rear derailleur could probably me made to work in another system but that
small spacing detail keeps SunTour shifters and freewheels/cassettes from being very useful in
other systems.

Occasionally someone will post that his mixed system shifts but that is probably due to the floating
top pulley or something that covers for the wider spacing at one end. It can't be perfect and is
often not fully functional.

--
Andrew Muzi yellowjersey.orgyellowjersey.orgOpen ↗ Open every day since 1 April 1971

etaoin shrdlu said:

How is indexing in the rear attained? The front I don't care about. Is it the combination of

- shifter & derailleur
- shifter & cluster (freewheel / cassette)
- derailleur & cluster
- shifter, derailleur, & cluster
- none of the above
- occurs only during a syzygy of three or more planets

I'm rehabbing a couple of bikes & wondering about how best to put components from different
manufacturers together (mainly SunTour & Shimano)

Thanks!

Phil

The shifter will move the cable a precise distance.

The cable will move the derailleur pulleys a precise distance in or out based on the geometry and
leverage structured of the derailleur.

The derailleur pulleys will move the chain a precise distance onto the cogs which are precisely
spaced to match the travel of the pulleys as moved by the derailleur as moved by the cable as moved
by the shifter.

Matching Suntour and Shimano shifting is not certain. Sometimes it will work, sometimes it won't.
Suntour used 'overshifting' in moving the chain to larger cogs, pulling the derailleur a touch
inside and then letting it drop back to the proper alignment.

Hopefully others will have more concrete information. I have some Suntour shifters that I don't want
to let go of, but the freewheels are on their last legs.

etaoin shrdlu said:

How is indexing in the rear attained?

The shifter does all the indexing.

The der, cluster, chain, etc... are all capable of operating as a non-indexed or indexed system.

Barry

Quoted message said:

- shifter, derailleur, & cluster

occasionally requiring

Quoted message said:

- occurs only during a syzygy of three or more planets

The shifter provides repeatable increments of cable pull. The derailleur reacts predictably to each
increment. The cluster has the proper spacing for the derailleur's movement (having properly shaped
teeth helps alot). In the rather old tome "Upgrading Your Bicycle," Frank Berto (long lost Bicycling
contributor) did a pretty nice analysis of the how all the parts fit together.

It's usually possible to mix clusters that are spaced similarly (current Shimano and Campy 9sp),
some that may be less obvious (Campy 8 and Shimano 7 ... careful with the limit screws). Shifters
and derailleurs are trickier ... a planetary conjunction might be necessary.

If you're rehabbing an older bike with Japanese components, I'd stick to Shimano for the shifter,
derailleur and freewheel.

R / John

etaoin shrdlu said:

How is indexing in the rear attained?

The indexing positions are a property of the shifter. The ratio between cable pull and lateral
movement is a property of the derailleur. The necessary lateral movement is a property of the
sprockets.
--
David Damerell <[email hidden]> flcl?