Our Z4 recurve limb is a complete redesign for us. This limb was built to take advantage of the incredible stability of the carbon we use. The carbon itself has been a 8 year evolution. I could not even guess how many different carbon lay ups we have tried. What we have found is that even carbon itself is not all created equal. The carbon that is on the back of this limb is not the same as the carbon that is on the belly.Because of this greatly increased stability and light weight of this carbon we are able to build a much higher pre-load static tipped limb. In doing so we have realized several benefits.
1) We have gained 7 fps with the Z4 limb over our Evolution limb. The Evolution limb is our previous carbon back foam core glass belly limb.The Evolution limb was no slouch itself. On our shooting machine with 10 grains of arrow weight per pound of draw weight. The evolution limb would shoot 190 fps when drawn to 28″. That puts the Z4 just on the door step of 200 fps with the same 10 gpp. We do our speed tests at 10 grains ppr because most of our customers are hunters and that is the most common arrow weight for hunters in our part of the country. If you prefer to shoot less grains per pound it is easy to see that 200 fps or more is an easy mark to hit. All of our speed testing is done on a shooting machine so it is completely repeatable.
2) The torsional stability of this limb is incredible. These limbs are so stable. I honestly do not believe you could intentionally twist one of these limbs. We have not sacrificed the vertical stability either. All of this translates to a more forgiving shot if you make a poor release because the limb tips are not pulled out of alignment.
3) Even with all of this performance they are still quite quiet and well behaved. Many limbs with this much preload could not be built because they would loose all stability. Making the limbs not shootable. The hand shock and noise would both go through the roof. That is not the case with this limb. They are very pleasant to shoot.
4) One of my favorite things about this Z4 limb is the draw force. If we just forget about all of the increased performance and stability of the limb the draw force itself makes this limb worth while. They are so smooth and draw 2 pounds per inch or less all the way to 30″ of draw length. That is on the SXT riser which is 14″ and our shortest riser. This part is purely a personal thing but I heard it so many times this past weekend I will mention it. The Z4 almost tricks your mind into thinking it has let off. We know it does not of course but it is because of the unique draw force. It is because of the way the tips start to hinge back as you draw the bow and the weight gain drops just below 2 pounds per inch. Not everyone could feel this in the draw but the vast majority did.
It does not matter whether you choose the 56″ or 64″ SXT with Z4 limbs they all draw nearly the same. If you have a longer draw you may want to choose one of our longer risers. We can build bows with Z4 limbs from 56″-64″ in length.
Since we have just returned from one of the largest traditional archery shoots in the country. We had an opportunity to talk to some of our customers that have our new Z4 limbs. So far the reviews have all been positive. The only real complaint we heard was that they had to relearn their arrow trajectory or go up in gpp because their arrows kept hitting high. The two stories that stand out most is one from a guy was able to extend his point on range by 10 yards when going from his previous carbon and foam limbs to the Z4. That is with the same weight bow and same weight arrow. Another guy told of his Z4 limbs shooting visibly faster than his other glass and bamboo limbed bow. That was not at all surprising until he told me that his glass limbed bow was 7 pounds heavier than his Z4 limbs. Again it was with the same weight arrow.
So that is the good on the Z4 limbs. Of course there are a couple of things that could be seen as negatives about this limb. As they say there are no free lunches. One thing that could be seen as a negative for some guys is that the limbs are only available with the carbon on the back and belly. Some guys just prefer the look of wood veneers. Its a personal thing. Myself I do not mind the look of the carbon. It has a nice woven pattern that is pleasing to me. The only other negative I can think of is the fact that carbon is expensive. It is expensive to produce and it is expensive to put in a limb. The carbon on the back and belly adds a total of $200 to the price of the limbs.