I think some are more than a little confused here. 'Trim units' refers to the units used in calculating c of g on a load chart and are based on the moment arm for the particular load item, be it SLF/fuel/food etc. They have nothing directly to do with 'stab trim units' where your green band lies. These are derived from the resulting C of G from the loading chart or computerised loading programme.
chksix - to answer your question - on the -700, the absolute aft limit is 30% MAC but decreases rapidly as you move away from a weight of 64T. The absolute forward limit, for interest, is just over 10% and ditto.
As I posted, with a D-L TS it is very easy to see the effect of trapped fuel on C of G.
Last edited by BOAC; 4th Oct 2014 at 08:40.