On Thu, 13 Aug 2009 02:39:57 -0700 (PDT)
MIG wrote:
the northbound at finsbury park and I very much doubt they would have
bothered to spend a fortune to enlarge it by a few inches so as 09 stock
has to fit through it must be pretty close to standard tube gauge.

B2003

Isn't it more to do with the bends rather than the diameter?

Beats me. If the carraiges are the same length as the current 67 stock
then they're shorter than piccadilly line ones so bends should be less
of an issue.

B2003