Not certain, But taking an educated guess I would have to say that they(Suzuki) must have been concerned about dampening vibrations that may have been comming through the foot pegs, this also may explain the thick rubber shoe used on the pegs too.
Just my guess
Actually guys, I believe the metal posts that hang on the bottom side of the pegs are "feelers" and not weights. Their purpose is to give you feedback as you lean further over and start touching parts down on the tarmac. Without them, the first part to touch down (if you have the nuts to lean that far) would be the exhaust which could cause you big problems.
The feelers are long enough to protrude below any exhaust work and touch first (I wore the ends of mine off- my riding buddies used to comment on the sparks!) which causes the footpeg itself to pivot up letting you know you're right there.
All that being said, I recently took the stock rearsets off and put on a set of fully adjustable Gilles aftermarkets. I'd highly recommend a good set of aftermarkets to anyone interested in being able to adjust their foot position and improve shifting.
A little pricey at $350.....but easy to install and well worth it!
OK, I got ya'. I'm sure those are for damping any vibrations that might run through the pegs. Strangely though, the Gilles have nothing designed to dampen vibration and they feel as smooth and vibration free as the stockers. They're actually light as can be and a huge difference over stock.