Arthur Clune wrote:
Simon Brooke wrote:

A 7, 8 or 9 speed chain has the same internal width as a 6 speed and
will work perfectly well. Plenty of six speed blocks still around,
ask in your LBS.

Will it? A 9 speed chain is a lot narrower than 6 speed even if it
has the same pitch. Not saying you are wrong, just that I'd be wary
myself.

From what I've read (I've not measured), internal width is similar and
compatible, but still I would get an 8-speed chain because they're cheaper
and the extra overall width might make it shift better.

~PB