Another thread on this forum started meandering toward the direction of Center of Gravity. There seems to be some discussion as to whether the CG will be raised or lowered by standing rather than sitting. I thought it deserved a thread of it's own. Let's hear waht everyone has to say. Here's my take: When you stand, you definitely raise the CG of "THE SYSTEM" This is a law of PHYSICS AND GRAVITY!!! However, part of "the system" has built in shock absorbers (legs and arms) which are not permanently fixed to the bike and a constantly adjusting counter balance (your body). So, while the CG of the bike is generally fixed, the masses of the rider are continually changing locations. The perception to the rider is based on the adjusted CG of the BIKE per the locations of the loads (rider + position) placed upon it, and not necessarily the CG of the system as a whole. Therefore, standing will lower the CG of the BIKE, and sitting will raise it. Someone once told me that loosing 1 lb on your bike (mtn bike) is like losing 10 lbs yourself. Your bike will feel lighter if you move weight from the bike to your back (water bottles, tool kits, etc.). Even though the system still weighs the same (and CG is raised), the bike feels lighter and easier to ride.