10sp chain on 9sp derailleur

[Russell]

I'm considering using a Santana 11-34 10 speed cassette (made by Shimano) which I assume uses a 10 speed chain.  What rear derailleur would I use with it?  What would happen if I used a 9sp mech.  It will be used with Campag shifters so a shiftmate will be used to take care of indexing.

Thanks

R

[bobb]

As far as I'm aware it will be fine. I'm sure someone will be along to correct me otherwise!

A mech is a mech. They may have "whatever speed" written on them, but as long as they have enough travel it won't make any difference. I think a Shimano 10 speed cassette is actually narrower than a 9 speed, so a "9 speed" marked mech should be more than able to handle it....

[vorsprung]

I'm considering using a Santana 11-34 10 speed cassette (made by Shimano) which I assume uses a 10 speed chain.  What rear derailleur would I use with it?  What would happen if I used a 9sp mech.  It will be used with Campag shifters so a shiftmate will be used to take care of indexing.

So let me get this straight.

A shimano 10 speed cassette with a very large max sprocket on a 9speed mech (campag or shimano?) with campag shifters(9sp?).  And a shiftmate?

Take a look at this article, it's quite detailed
Rear Shifting

[Biggsy]

A mech is a mech. They may have "whatever speed" written on them, but as long as they have enough travel it won't make any difference.

There is more to mechs than that when used with indexed shifters.  A mech with a different geometry may travel a different amount per index position - although I don't think it is different in this case, or with most Shimano stuff.

Also the cage width may be narrower with 10-speed to optimise shifting with a narower chain.  This is a minor point though.

[Russell]

I think my main concern would be running a narrow 10sp chain on a mech designed for 9sp width chain.

I was considering 10sp Campy shifters and a SRAM X (1:1) series long cage mech using a shiftmate #5S.

Jtek Engineering Shiftmate

The mech has enough capacity to handle 11-34 and the shiftmate will sort out the indexing.

Santana use an Ultegra mech as standard (with Shimano shifters of course) but as I would need a shiftmate to use Campy shifters and I like SRAM mechs this seemed like the way to go.