friction shifters linear gear shifts?

[G.Daniels]

any hot ideas on how to adjust friction mechanisms to
produce linear shifts at both top and bottom rear cogs?

 

[Sheldon Brown]

g.daniels wrote:

> any hot ideas on how to adjust friction mechanisms to
> produce linear shifts at both top and bottom rear cogs?

no such possibilitude due to constant radius of cable drum
vs cosine error in derailer linkage unless you use an old
coil-spring derailer like a benelux mark viii or vii
ofcourse you could 'facture a fricter with variableradial
cable drum

sheldon "dontneed no steenking punctuationor shiftkey-
dontcare if messageis comprehensibible" brown +------------------------------------------------------
+
| You only get as strong as your smallest gear. | If you
| only have one, that's how strong you get. | -- Mike
| Shaw |
+------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts Phone 617-244-
9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find
parts shipped Worldwide http://captainbike.com
http://sheldonbrown.com

 

[G. Huang]

g.daniels wrote:
> any hot ideas on how to adjust friction mechanisms to
> produce linear shifts at both top and bottom rear cogs?

I believe the friction shifter is linear in the sense that
the amount of cable pulled is a linear function of the
angular position of the lever. The derailleur may not
linearly translate the cable-pull to the displacement of the
cage, and I don't think that is adjustable. GH

 

[Benjamin Lewis]

Sheldon Brown wrote:

> g.daniels wrote:
>
>> any hot ideas on how to adjust friction mechanisms to
>> produce linear shifts at both top and bottom rear cogs?
>
> no such possibilitude due to constant radius of cable drum
> vs cosine error in derailer linkage unless you use an old
> coil-spring derailer like a benelux mark viii or vii
> ofcourse you could 'facture a fricter with variableradial
> cable drum
>
> sheldon "dontneed no steenking punctuationor shiftkey-
> dontcare if messageis comprehensibible" brown

I'm somewhat embarrassed to say it, but I understood you
perfectly.

--
Benjamin Lewis

Don't take life so serious, son, it ain't nohow permanent.
-- Walt Kelly

 

[Rick Onanian]

Sheldon g.danielized:
>> sheldon "dontneed no steenking punctuationor shiftkey-
>> dontcare if messageis comprehensibible" brown

<[email protected]> wrote:
>I'm somewhat embarrassed to say it, but I understood you
>perfectly.

You're well practiced from reading g.danielsese.
--
Rick Onanian

 

[Benjamin Lewis]

Rick Onanian wrote:

> Sheldon g.danielized:
>>> sheldon "dontneed no steenking punctuationor shiftkey-
>>> dontcare if messageis comprehensibible" brown
>
> <[email protected]> wrote:
>> I'm somewhat embarrassed to say it, but I understood you
>> perfectly.
>
> You're well practiced from reading g.danielsese.

It may also be from several readings of _Riddley Walker_ by
Russell Hoban.

--
Benjamin Lewis

Gravity is a myth, the Earth sucks.

 

[G.Daniels]

right! i cudn't have writ it better.
butbubtut, i examined (loosely put) the problem or at least part of it
on a long straight yesterday into the wind and alone on the wide
mulsanne thus avoiding the SEE ROCK CITY signs and dirt bikers with
friction shifters.
and what i came up with bedies double vision wuza the:

SHADOW GEAR!! the(ah expletive deleted i furgot to count
it's teeth)3 cog down from the 34-32-shadow gear/28?-24? is
a skip running with the small CR going to the 32 and to the
24 from the 32 unless the cable is turned pretty tightly.
the 3 cog from the bottom does something likewise but not as
often prefering to thrum instead. eye guess(whew that's
along ways aback there)the linear fucntion is performed by
the large CR and if needing accuracy so as to avoid physical
damage to the pudendal area, scrotum, and ACL, the big CR is
the way togo. the two 3 cogs on this non-linear setup takes
significant effort(s) to get into even in the spread the
wear riding mode but taking the hairpin flatout mode
requires the extra cablescrew twist and the big
CR.this is the reason or one of the reasons for index
shifting on the new bike?