Q.  Does changing the draw length change the draw weight?

A.  Changing the draw module does not affect the draw weight.  Changing the draw length by shortening or lengthening the string or string position will affect the draw weight.  The longer the string, the higher the poundage.  The shorter the string, the lower the poundage.

Q.  How is draw length measured?

A.  Draw length is measured when the bow is at full draw and being held in the "valley" or the highest let-off point on the dam.  The measurement is taken from the point where the nock is attached to the string to a point 1-3/4" in front of the pivot point of the grip.  In other words, from the nocking point on the string to roughly the front edge of the bow.  Draw length is not measured to the arrow rest mounting hole as many people think.

Q.  How often should strings and cables be replaced?

A.  This depends on how much shooting you do.  If you shoot 3-4 times a week and also a winter league, then you should change your string and cable once a year.  We recommend doing this about 2 months before the hunting season.  Be sure and save the old string and cable as a back-up set.  If you somethow cut either one during the season, you'll have one ready to go.

Q.  What is brace height?

A.  Brace height is the distance, when the bow is at rest, from the string to the deepest point of the grip.  Today's bows generally range from 5-1/2" to 8-1/2".

Q.  How are speeds determined?

A.  There are two standards by which speed is measured,

IBO ratings

AMO ratings

IBO stands for International Bowhunting Organization.  IBO testing uses a 70# draw length and mandates the 29" arrow be 5 grains of weight per peak pound of draw weight, So, IBO speeds are obtained using a 350 grain arrow (70#'s of draw weight x 5 grains per pound).

AMO is the Archery Manufacturer's Organization.  The AMO speed standards use a 60# draw weight, a 30" draw length and a 29" arrow at 9 grains per pound of draw weight.  So, in AMO you are testing with a much heavier arrow at 540 grains (60# draw weight x 9 grains per pound).

Speed testing is generally performed using a mechanical shooting device such as a Hooter Shooter which maintains consistency between each shot and eliminates human influence on the shot.

Q.  Why do arrows with broad heads fly erratic, but arrows with field points fly great?

A.  There are three important factors that affect arrow flight:

Center shot

Bow tune

Aerodynamics

If your center shot is not set properly, your windage (left to right) and elevation (up and down) will be inconsistent.  The problem may not be noticeable with field points but will be exacerbated and more obvious when the aerodynamics of a broadhead are introduced.  

Bow tune is series of measurements and adjustments made to any compound bow that ensures the bow is functioning properly. Bow tune includes such things as tiller measurement, poundage settings, arrow rest alignment, setting the optimum nocking point location, etc.

Aerodynamics can come into play with a fixed blade broadhead as it is propelled down range. Fixed blade broadheads and the shafts they're mounted on need to be tuned to ensure there's no wobble and the shafts spin exactly true. This is important to prevent the broadhead from planing or catching wind currents in such as way as to cause erratic results.

Terminology

String Stretch

Elongation or string stretch is the amount that a particular string material will lengthen when put under tension.  There is always some initial settling of the string and cable after the bow is built.  Mos of that stretch willhapped before you ever get a bow out of the box.  The last bit of stretch happens in the first 50-100 shots.  That's why you should wait until the bow has been shot some before making any final adjustments or settings.

Today's string and cable materials and more importantly, the string-making processes, are far better than in the past.  Because of that, string stretch is not that much of an issue for most bowhunters.

Be aware that physically damaging of any of the individual strands of the string or exposing the bow to excessive heat can cause a string to stretch even after it has "settled".

Tiller

Tiller is a measurement taken to help determine if the limbs of a bow are in balance.