get you from 9/9.5 to 12.5-13 (3 lbs?) the inline adapters would probably give at most .25 lbs - if you get the same inner diameter coupler as the hose all you are doing is stretching the hose a bit to get it over and coming up with the same inner diameter...you might argue that there is a bit of a restriction based on a rough transition from hose to coupler, but it would be so negligible it wouldn't register as a change.