weight

Why is the current sportbikes 40 lb's heavyer then the same models from 5-6 years ago?  

What you're probably referring to is the listed weights that the manufacturers are now posting on their websites and promotional literature.

Back in '07, the manufacturers agreed to publish weight specs that were more realistic to what the consumer could expect to see on a bike off the showroom floor (American Honda reps claim that they pushed for this agreement first). This led to the weight specs listed with a full tank of fuel and all other critical fluids present (coolant, oil). In the past, the manufacturers used to list "dry weights"; these were achieved by omitting such items as fuel, all fluids (suspension and motor oils, coolant), battery, brake pads, and even tires. The manufacturers' reasoning behind this was that because many of these items were changed for various foreign markets and considered "consumables", they couldn't guarantee a weight spec that would apply "worldwide"...so they excluded them. You obviously wouldn't ride a bike without any coolant or oils or tires, so the previous dry weights they used to list were completely unrealistic.

This was why we always weighed test bikes on our own Intercomp digital scales (unless they were one-day initial impressions from manufacturer press launches), instead of just taking the manufacturer listed weights...and will continue to do so, even though they are now listing specs that are more in line with reality.  

So what your tellin me is that the liter bikes of today are still under 400 lbs, dry?  

Only if your interpretation of "dry weight" is an unrealistic figure with no fuel, motor or suspension oil, coolant, battery, brake pads, and tires...