I have the marginally on-topic 600 6207 short-cage, and it works well with a cluster up to 28T. I tried a long cage 600, and it is one of the worst rear mechs, in terms of achieving shifts. The second Rally is somewhat better, and the Duopar and Ecopar are both far better in terms of shifting quality. With a Duo or Eco, th cog jump is essentially of no concern due to the vertical parallelogram.
On Sunday, January 31, 2010, Brent Davis <brentssc@gmail.com> wrote:
> "With a 5 speed cluster, what is the limiting factor for shifting? In other
> words, does it matter how many teeth difference from one cog to another, or
> is it the length of the arm on the rear derailleur. For example, if my
> largest cog has 34 T, would it matter if the rest were 14, 16, 18, 23, or
> would the need to be more like, 14, 16 20, 28? Likewise with the front;
> what is the largest size DIFFERENCE that can be handled by the front
> derailleur? My derailleur set is Shimano 600.
> Thank you,"
>
> David Kulcinski
>
>
> Tooth jumps only matter if you want smooth shifting , with what you prosose
> you will need a long cage der. 28 is out of the ease of use fora 600 short
> cage 26 is tops and even then a comprimise must be made. Remember short cage
> der of the period especally the Suntour and Shimano weremade for straight
> blocks with a top gear of 21 and 24 for a special case they really were
> happiest with a top of 19 .
>
> 14 tooth difference is standard for Ft der of the period a touring der of
> the periof will five you more ability to have a a larger tooth difference.
>
> --
> Brent Davis northshore of Boston
>
> [ url= http://www.grifynsawyer.blogspot.com/
> _______________________________________________
>
--
Ken Freeman
Ann Arbor, MI USA