Shimano 10-speed derailleur with 9-speed

hawkk said:

According to Shimano's website, the 10-speed rear derailleur is
compatible with the 9-speed cassette. How is this possible given the
different spacing between the 9-speed cogs and 10-speed cogs?

Gig

Because the shifter is responsible for how far the derailleur moves per
click.

Lou
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Posted by news://news.nb.nu

I am getting ready to build up a new bike. I want to stay with a
9-speed system. If I go with the new Shimano Ultra 6600 crankset, can I
still use a 9-speed chain such as the SRAM?
Thanks,
Gig

hawkk said:

I am getting ready to build up a new bike. I want to stay with a
9-speed system. If I go with the new Shimano Ultra 6600 crankset, can I
still use a 9-speed chain such as the SRAM?
Thanks,
Gig

Match your chain with your cassette. 9 speed cassette is 9 speed chain.
Crankset doesn't matter.

Lou
--
Posted by news://news.nb.nu

Lou, thanks for your help!

hawkk said:

According to Shimano's website, the 10-speed rear derailleur is
compatible with the 9-speed cassette. How is this possible given the
different spacing between the 9-speed cogs and 10-speed cogs?

Gig

The cable pull determines the amount the rear der moves. 10s STI moves
the rear der the proper amount. The two ders, 9s and 10s, are the same
dimensions, so the lever via cable pull, determines the amount the RD
moves.