The ABC Pivotal Bowsight is NOT a Simple Pendulum Sight
the late 1970s, literally tens of thousands of bow hunters have benefited
from the advantages of tree stand sights. Many manufacturers now produce
tree stand sights, almost all pendulums. The average bow hunter is left
wondering what sight is best. Should your choice be based on another archer’s
"This one is the best"? Should it be based on aggressive ad campaigns,
on a sales clerk who wants an easy sale or on your own personal knowledge?
Let’s take a look at tree stand sight designs so that as an informed consumer
you will make an informed purchase.
In the mid-late 1970’s, when compound bows still had 4 wheels, Bob Keller invented the first pendulum sight. This sight, now known as the Keller pendulum, is the grandfather of all pendulum sights currently available. Keep in mind that bow speeds of this era were averaging 180 to 200 feet per second, and therefore bow hunters needed help estimating yardage on virtually all their shots.
Pendulum sights are very simple in design. A sight pin is placed approximately 1" in front of an axle and weight is added to balance the pin. As the bow is raised the pin appears to lower allowing the archer to shoot at an unknown distance. The perception of the pendulum pin moving is false.
Technically, a pendulum pin remains at its balance point and you rotate your bow around it. Pendulums are limited to approximately 30 yards. With no real provision to change the pins arc, pendulums can be woefully inaccurate, especially on today’s high speed bows.
Pendulums advertise that they can compensate yardage from 14 ft. to 30 ft. What they do not tell you is that if you change your tree stand height from your original sight-in height, you lose accuracy. If you go higher in your tree, you will miss low. If you go lower in your tree, you will miss high. This is because pendulums respond to angle not distance changes. Tree stand height changes cause angle changes to the sight. Although the distance is the same, the sight doesn’t adjust properly, causing a loss of accuracy. This is a simple mechanical function which holds true for all pendulum sights. If the manufacturers claim otherwise, they’re misleading you.
Virtually all of today’s tree stand sights are pendulums of this design. Sure they look different and make many claims, but just look at their design and you’ll see that when you move the sight housing the pin does not move. This includes the Keller Pendulum, Predator Eliminator, Cobra, Browning and every other tree stand sight on the market except one...
Pivotal Bow Sight System