retro rear mech 'speeds'

[bikenut2010]

You see a lt of older deraiilleurs advertised as '6-7 speed', or '8 speed indexed' etc etc.
I always thought it was down to the shifters?
Clearly modern 10 - 11 speed groups is another matter, but would a Shimano 105 rear mech that I've been using 6 or 7 speed friction behave itself with Shimano 8 speed indexed for example?

I heard there are issues with Suntour mechs pulling a different cable length, but what do the gurus say?

 

[daccordimark]

If I read this right - http://www.ctc.org.uk/desktopdefault.aspx?tabid=3946 - all Shimano mechs have the same shift ratio so in theory your old friction mech will move the same amount per click as a new "made for indexing" mech.

If you're using indexed downtube levers you need a cable adjuster on the rear mech to take up slack as time goes by and old friction mechs didn't usually have those.

I should add I haven't actually tried it with Shimano myself.

Mark.

 

[bikenut2010]

If I read this right - http://www.ctc.org.uk/desktopdefault.aspx?tabid=3946 - all Shimano mechs have the same shift ratio so in theory your old friction mech will move the same amount per click as a new "made for indexing" mech.

If you're using indexed downtube levers you need a cable adjuster on the rear mech to take up slack as time goes by and old friction mechs didn't usually have those.

I should add I haven't actually tried it with Shimano myself.

Mark.

Cheers Mark


found these online at the right price...
http://www.chainreactioncycles.com/Mode ... delID=8620

 

[kula]

Hi, have used a 6/7 speed Shimano 600 rear mech no probs over 8 speed.
The only problems come with trying to use Dura Ace rear mechs like the 7 speed one 7400 or something like that with non Dura Ace shifters.
I can get my Dura Ace rear mech working with the first generation 600 STI 8 speed, but the cable goes a different route through the pinch bolt.

 

[bikenut2010]

DA

Ha, i'm running 7400 rear mech with 600 7 speed and I do get a bit of chain s;ip when climbing hard, maybe that's the issue, is there a pic of the alt cable route or the same as Sheldon Brown?

 

[kula]

Yes the Alternate Cable Routing method as in Sheldon Brown.
I don't use the DA with 600 8 speed anymore as I've gone down the 10 speed route to get a better spread of gears.
But the alternate route does work quite well. Took me more time twiddling the adjustment on the rear mech and on the old fashion gear lever boss adaptor to get it working smoothly.