I thought those heavy webbed inner rings were actually from the
days when TAs were the M*B(OFF TOPIC) cranks of choice.
Those may indeed have started life as a Tandem spec inner. I have had a
number of these pass thru my garage and probably still have 1 or 2 out
there.Seems they were always high tooth counts like 48 or 49. Also I do
not recall an outer with corresponding wide webbing.
BOB FREITAS
rained all night in MILL VALLEY ,CA USA