kaizerchief said:
oh i see. thanks for the help. but how can u tell from the table that it would give and 7 speed equivalent?
BTW. If you look at the '
Campag 11' line then you will see that 7-speed & 8-speed ('
S7/8') share the same box ...
kaizerchief said:
oh. my bike now uses a shimano sis tourney could i keep using that? also what does the pitch and cable column of the table mean?
Well, I am going to say that you CAN probably use your Tourney rear derailleur BECAUSE (
as I mentioned) the
ramping on the rear Cogs (
BTW,. many/most pre-2000 Freewheels & some Cassettes may not have ramped Cogs ... it is hopefully not an issue for whatever your bike has) makes the precision of the shifter's indexing less relevant when using Campagnolo shifters ... but, there are no guarantees. In the worst case scenario, you'll have to pony up for a new/different Shimano rear derailleur (
e.g., Acera, LX, SLX, XT, etc.) ...
Unless you are a
Flatlander, I recommend that if you do feel a need to change rear derailleurs that you choose one of Shimano's
MTB rear derailleurs because you will have more future flexibility with regard to your rear Cassette-or-Freewheel ...
That is, Shimano's MTB rear derailleurs can accommodate Cassettes/Freewheels which have larger Cogs than Shimano's Road derailleurs can handle.
If you need to buy a different rear derailleur, then I recommend a vintage
XT 750 SGS rear derailleur (
generally less than $30 on eBay) which is in good-to-very-good condition (
while it does not provide any certainty, if you look at the wear-or-lack-of on the pulley wheels and/or trust the seller, then you can get a very rough gauge of how much use-or-abuse a rear derailleur may have seen) ... or, an
SLX rear derailleur (
be sure that it has "normal" pull and not "reverse-pull"/"rapid rise") ... because it won't be wedded to your current bike.
You can move the "new" derailleur to a different bike in the future OR put in your "toolbox"; so, nothing will be lost if you pony up a little more for an SLX or XT rear derailleur.
The "Pitch" is the distance between the central plane of the individual Cogs ... imprecisely speaking, the Cog spacing ...
Essentially, the amount the rear derailleur's cage moves between shifts.
The "Cable" is the amount of cable which is
moved by the shifter through an arbitrary
/theoretical fixed point ...
So, if you were to put a piece of tape on your frame's downtube AND a piece of tape on your cable along side the fixed piece of tape, then if you put a line on the one + a matching line on the other AND THEN actuated your shifter by "one click stop" then you would see the the once aligned lines separate by the "Cable" value (
measured in millimeters).
The rear derailleur's geometry has
some effect on how much the rear derailleur's cable movement affects the "pitch"; but, YOU don't have to worry about
THAT.