Originally Posted by
ROJA
...The top one seems to work with a moderate level of effort (meaning that if I release the bottom QR, it still requires a fair amount of effort to turn the seat). The lower QR, however, only seems to tighten up if I really clamp it down hard.
There's greater mechanical advantage when the distance between the seat and QR is increased.
Experiment:
Take a sturdy spoon and hold the spoon (concave) part between thumb and forefinger and then with the thumb and forefinger of your other hand, grip the handle of the spoon tightly, very close to the concave part. Now twist the concave part with one hand while trying to keep the spoon from twisting with your other hand. Detente. Now, hold onto the handle near the far end and twist the spoon-end. Spoon twists.
Stubby screwdriver versus long screwdriver.
Regards
T