Changing It Up: Review of the Prime Rize

I decided that I wanted to try shooting a different bow this year. I have such a curiosity and excitement with archery technology and products that I can’t help but want to try everything I can get my hands on. So far, I’ve always shot Hoyt, and they’ve been great bows, but there are so many manufacturers making great products, I thought it would be a good idea to see how another one felt.

Archery is a growing sport, and within the hunting community, I think bowhunting is also increasing in popularity. You get longer seasons as a bowhunter, a different kind of challenge, and there’s a passion among bowhunters that is just unrivalled by any other activity I’ve ever experienced. For those people getting into archery, it can be daunting trying to make heads and tails of riser designs, cam designs, accessories, arrow selection, and the technical specifications of speed, weight, axle-to-axle length, brace height, and kinetic energy.

I posted about my previous Hoyt Charger setup and some basics about why I chose the accessories I did for that setup, so here is a review of my new bow and some reflection on how and why I made the decision this time around.

I just purchased the brand new 2016 Prime Rize. rize_black_with_damper-web In terms of specs, the Rize has a redesigned PCXL parallel cam system, the brand new 82X aluminum riser, it’s 33″ axle-to-axle (ATA), 6.75″ brace height, weighs 4.3 pounds, shoots an IBO speed of 335 feet per second (fps), and my bow has a peak draw weight of 70 pounds.

Ok, so for those who don’t necessarily know what all of this means, head over to my Introduction to Archery post for some background on the terminology.

To set up how I came to choose the Prime Rize, these are the main factors I consider when choosing a bow, in order of importance to me:
1. Balance/stability (at full draw and on release)
2. Consistency/tuning
3. Back wall
4. Release
5. Sound
6. Draw cycle
7. Speed

Some of these overlap, and some I would probably rate equally important. Generally speaking, I’m looking for a bow that I feel confident shooting every single time. It needs to sit in my hand like it belongs there – before, during, and after the shot.

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When I put all those considerations together, I decided on the Prime Rize. Prime’s parallel cam system is supposed to make their bows extremely efficient and reliable to tune.

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Prime’s parallel cam system.

 The limb stops are designed to give a super solid back wall (for people familiar with Elite bows, this is about what a Prime feels like). The aluminum they use for the risers are designed to give an extremely stiff riser, providing both stability and silence on release.

So let’s go through my list of priorities and see how the Rize is looking so far. I’ll jump around my list a bit because it makes more sense to go in order of shot sequence.

Let’s start with the long list of pros…

My first few shots felt amazing. Drawing this bow at 70 pounds felt more like others I’ve drawn at 60 pounds. With the limb stops, it sits at that back wall like there is literally a wall behind my back arm. Some people will cringe at this thought, but I’m really liking it. If I want to hold the bow drawn for any length of time, I want to be able to really squeeze my shoulder blades back and hold the bow there without any movement – I don’t want it to feel spongy or like it’s pulling forward. Other bows will use cable stops, which use the cables to hold the cams at full draw rather than the limbs. This just gives a different feel when holding the bow at full draw, and it really comes down to personal preference.

A note on draw cycle that will certainly be at the top of other people’s lists: I’m not too concerned with having the smoothest drawing bow. When I draw a bow, I’m pulling back a string that will shoot a projectile close to 300 fps with 70 pounds of force. I don’t mind feeling that. I mean, comfort is always nice, but I just personally don’t mind more aggressive cams that I need to power through a bit to get drawn (don’t confuse this with being physically incapable of drawing the bow, which is just a recipe for injury and damaged equipment). As long as I am physically strong enough to get the bow drawn while still holding the pin on target, I’m happy. This would be the difference, for example, between a Hoyt turbo cam, that is very aggressive, and the famous Mathews solo cams, that are well known for their smooth draws.

On release, there’s so little movement, it’s unbelievable. I never felt like the bow was jumping at all; it is completely dead in hand – also making it extremely quiet (the other people in the shop even commented on this). This feeling is a hard one to describe, but anyone who has done some shooting knows the difference between a bow that jumps and one that just seems to slide from full draw to the shot. The Rize sits in my hand really comfortably, and settles right in at full draw.

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The ghost grip is super thin but also textured.

 Prime’s “ghost grip” is essentially just a super thin, low profile grip that is slightly textured, but no rubber or wood. I’m used to Hoyt’s rubber and wood grips, so this was a bit different for me, but I am enjoying it. One thing I noticed is that if there was any moisture on my hand (sweat, rain, etc.), it did make the grip feel a bit less secure in my hand; however, in terms of feeling the bow sitting right in my hand, I am really enjoying the thin grip.

I can’t fully comment on tuning yet because I just haven’t put enough shots through the bow to see how the strings and cables will settle in and how the bow will maintain tuning. Consistency/tuning are extremely important to me. I need to know that I can trust my bow to be shooting exactly the same with every shot. This way, I know that any inconsistencies and errors are mine. I have personally found that Hoyt bows can be a bit time consuming and a little tricky to tune. Don’t get me wrong, they are incredible bows and perform very well; but I have found they need a lot of attention to get the arrows shooting just perfect through paper and with broadheads. So I want a bow that I am confident will stay in tune and will be shooting the same in the field as it was in the shop.

What I can say is that I felt pretty confident shooting it right out of the box. Prime cycles their bows 100 times and then retunes them before they leave the factory, so much of the stretching in the strings and cables should already be done. The parallel cam system is intended to eliminate the issue of cam lean (when the cams are canted to one side as a result of different tension on the cables), so I’ll have to see how that goes after I get a hundred arrows or so out of the bow, and update then.

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Another shot of the parallel cam and the split string that comes together to the main string.

 Binary cam bows can sometimes be a bit notorious for addressing cam lean issues, so this will be a big test for the parallel cam system.

The other aspect to tuning that I worry about is cam timing (ensuring the cams are moving together and in sync). I contacted Prime right away and asked them to send me any instructions they have on addressing cam timing, and they replied with these materials within hours. The adjustments seem to be really straight-forward, and the cams have markings on them that can be used to ensure they are in the same position at rest. This means that you can measure cam timing with the bow at rest, which is great. What I can say is that I installed the rest and nock point based on the manufacture specifications, and it took one small rest adjustment to get the bow shooting bullet holes through paper. So in terms of paper tuning, it was great.

If I have to identify a con…

One thing I will say is that I hope I never have to let the bow down from full draw. I had to do this twice while setting the bow up, and it was very uncomfortable. The flip side of a really nice back wall is that you almost have to push the string forward to let it down, and when those cams roll over, it’s very uncomfortable on the shoulder. Having said that, I can probably count on my fingers and toes the number of times I’ve actually let a bow down without shooting, so I don’t expect this to be a big issue.

And a con that has become a pro…

One of my initial hesitations with moving to Prime was the weight of the bows. When I first shot a Prime a couple years ago, I noticed immediately how heavy it was, and it really turned me off. They have definitely addressed this in the last couple years. The Rize is certainly a manageable weight, even after I installed my stabilizer and other accessories. It also just feels like a really solid piece of equipment. There’s a more qualitative impression you get when you pick up a bow about its durability, and the Rize sure seems like a workhorse.

A note on speed…

Speed is one of the most hotly debated topics in archery and bowhunting. I’ve discussed the issue of speed in another post about arrow selection, so I’m not going to go into it in detail here, but I will give the specs on what I’m getting for speed. When I shot a couple arrows through a chronograph, I was getting an average speed of 289 fps with my Easton Axis arrows. My arrows are in a 340 spine, weighing 9.5 gpi, so at 28.5″ long they come in at 414 grains total weight. This gives me 77 foot pounds of KE out of the Rize, a number I’m definitely happy with.

Summary:

All in all, I think it’s a great bow so far. I need to do a lot more shooting and of course get it into the field for some hunting, but I’m happy with it. I would definitely encourage everyone to check these bows out and give them a try. At the end of the day, choose your bow based on what feels right. Don’t buy a bow you don’t think you will be confident with in the field. Read through some other reviews (here’s another great review of the Rize as well) and see what people like about their equipment. There are many variables and considerations, so it’s important to get some bows in your hands and see what is most important to you and then decide which bow suits your preferences the best.

Questions about this bow or setup? Feedback or suggestions about this review? Leave them in the comments section and I’ll definitely address them!

Arrow Selection: Some Considerations and Choices

When it comes to nerding out about archery gear and archery science, I’m guilty as charged. One of the most important considerations in putting together a bowhunting rig (and a topic that stimulates a lot of conversation) is arrow selection. Everything comes into play in choosing an arrow: what are you hunting? What kind of bow are you shooting? How much speed do you want? How much kinetic energy do you need? The answers to these questions all depend on your priorities and your hunting situation.

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Foreward: What is Really at the Heart of the Speed vs. Power Issue?

The debate around arrow selection often revolves around one main question: to be fast or not to be fast? Or more specifically, do you want a fast arrow or a powerful arrow? Most of the rest of your decisions come from your answer to this question. I imagine that archers have been engaged in this conversation for thousands of years, at one point having lively debates into the night over the type of wood to use for their arrows. Arrow weight is the single most important characteristic that determines the results you are going to get for speed and power.

Generally speaking, I think the race for the fastest arrow is a bit moot. However, manufacturers need an easy way to assign some kind of value to their bows, and people are drawn to fast things. It’s easy to want a bow that shoots at 370 feet per second (fps) over one that shoots at 280 fps.

But let’s back up. There are a couple other important considerations besides speed, so let’s look at the science and see how this need for speed plays out.

I’m going to focus on three main points for this discussion:

Act 1: Ensure you have the correct spine.
Act 2: In the bowhunting world, weight kills.
Act 3: I think there is a specific, but important, difference between seeking seeking a fast arrow and seeking a fast bow.

Of course, there are many things to think about when choosing arrows, but I think these 3 points will give you a good start when first tackling arrow selection. You will need to spend time doing plenty of research, doing some calculations, and figuring out what works best with your bow. I hope reading this article is one part of that research.

Act One: Arrow Spine

The first thing you need to know when selecting an arrow is what spine you need. Most choices in arrow selection come down to personal preference, but not spine. Arrow spine refers to the stiffness of an arrow, and it’s critical for the safety of your bow and for accuracy that you choose the correct arrow spine.

Imagine you drive a truck into the end of a horizontal telephone pole. Imagine  you drive the same truck into a tooth pick. Finally, imagine you drive it into a 2×4. While perhaps a little rough around the edges, this analogy is meant to explain what happens if you shoot an arrow that is too stiff or too weak for your bow. When the bowstring pushes the arrow off the end of the bow, the arrow flexes, stabilizing throughout the course of its flight. Simply put, if your bow is too weak, the arrow can`t flex enough; if your bow is too heavy, the arrow flexes too much. At worst, these situations could damage your bow, but they will certainly reduce the consistency and accuracy of your shooting. The rule is that heavier bows require stiffer arrows.

Every arrow manufacturer has a way of designating the spine of their arrows, and while the system used to measure spine stiffness is standardized, the systems used by manufacturers to represent spine is not. Easton’s system is generally the easiest to understand, because they use the direct measurement for “arrow deflection“, which is the way spine stiffness is calculated. With Easton arrows, the lower the number, the stiffer the arrow. 20151218_232210So a 70# bow might shoot a 340 spine arrow, while a 60# bow might shoot a 400 spine arrow. All arrow manufacturers will have charts (Easton, Carbon Express, Gold Tip) to help you identify the correct arrow spine based on your bow specifications (e.g. poundage, draw length, and arrow length). Be sure you understand how your specifications affect spine selection. Click here for a great resource to explain some of the finer points in arrow spine.

Act Two: The Science Part

Here’s the science in bowhunting: arrows kill by haemorrhaging, doing internal damage by cutting. Ideally, you want both an entrance wound and an exit wound. Therefore, an arrow’s ability to kill depends on effective and powerful penetration. The ability of an arrow to penetrate depends on kinetic energy (KE) and momentum. Kinetic energy is the energy an object possesses as it moves. Momentum is the relationship between speed and mass of an object. We could get into the differences between KE and momentum, but this is meant to be an introduction to the topic, so for simplicity, I’ll use KE to refer to the ability of an arrow to penetrate effectively.

Imagine that you have two cups. Fill them both half full with water. The first cup is speed; the second cup is the arrow weight. You can pour water from one cup to the other, gaining more speed and reducing weight, or vice versa, but there’s a trade off either way. Together, the interaction of the water in the two cups determines your KE.

As a rule, light arrows travel faster than heavier ones. Think of the difference between throwing a golf ball and a bowling ball. We will all be able to throw the golf ball faster. Speed is great in getting an arrow to the animal quickly, but as soon as the arrow touches the animal’s hide, it stops. At this point, the energy required to penetrate is stored in the arrow as KE, meaning that you need to optimize the amount of KE in the arrow. In the equation to calculate KE, the speed of an arrow has less influence over its killing power than the mass of that arrow. Therefore, the heavier an arrow is, the more KE it will have, and the more penetrating power it will have at the animal. I would rather be hit with a golf ball than a bowling ball, because even though the bowling ball is going slower, it is more powerful.

Some people will say that the faster the arrow is, the less time the animal has to react to it and jump the string. That’s true; however, sounds travels at 1,116 fps. The fastest bow in the world is still pushing an arrow slower than the speed of sound, meaning that the sound of the bow shooting will reach the animal long before the arrow. In other words, no matter what, the arrow can never be fast enough. So again, the real focus is on the ability of that arrow to kill the animal efficiently and effectively when it does reach its target.

To calculate the KE of your arrow, here is the equation:
KE=(mv²)/450,240

m = mass. The mass of modern arrows are described in grains per inch (gpi). Most arrows will have the gpi marked right on the shaft. To calculate total arrow mass, take the length of your arrow in inches and multiply that by the gpi weight of the arrow, and then add everything else on the arrow: vanes, nock, insert, arrow head.
v = velocity. You will need to shoot your arrow through a chronograph. There are calculations you can do to estimate your arrow speed using bow poundage, draw length, and arrow weight, but to be absolutely accurate, you need to use a chronograph.

Here’s an example using my old bow and arrow setup. I was shooting an arrow that weighed 9.0 gpi, was 28.5″ long, and had a total arrow mass of about 400 grains. I put it through a chronograph at 282 fps. So if we plug in those numbers, here’s what I was shooting for KE:

KE=(mv²)/450,240
KE=(400×282²)/450,240
KE=71 foot pounds

Here’s a handy resource for some other useful calculations.

So if KE kills animals, the next question is, how much KE do I need?

We don’t really know precisely how much KE is needed to kill every animal. Every bowhunting situation is different, but generally speaking, larger animals require more KE. Easton provides an estimated range of recommended KE for animals of different sizes:

Small game (rabbits, groundhog, etc.): 25 ft. lbs.
Medium game (deer, antelope, etc.): 25-41 ft. lbs.
Large game (elk, black bear, etc.): 41-65 ft. lbs.
Toughest game (buffalo, grizzly bear, etc.): >65 ft. lbs.

So that gives you an idea of what you should aim for depending on your hunting scenario. My position is that there is no such thing as “overkill”; you can’t have too much power. The more the merrier.

Check out this video comparing penetration between two different bow and arrow combinations.

It is worth spending some time doing the calculations, checking the numbers on different arrows, and thinking about what you will be hunting and what you need. Think about how much poundage you can handle in your bow and what kind of arrow weight you need to get the KE needed for quick kills. This brings me to my third point.

Act Three: The Real Need for Speed…Bow Poundage

Having said all that about arrow speed, I would bet that deep down, we all still want a fast arrow. Plus, there is some scientific basis for this: recall that velocity is a factor in KE, so it is important to have speed.

The IBO speed rating on a bow is determined using a 70# bow with a 30″ draw length and a 350 grain arrow. By hunting standards, 350 grains is on the lighter end of the spectrum. So what can the IBO rating tell you about what you can expect from the bow once you start shooting your hunting arrow? Well, since IBO ratings are standardized, it gives you some indication about the efficiency and power of the bow itself. A bow shooting IBO speeds of 350 fps is still going to be faster than one shooting 320 fps, even at lower hunting arrow speeds.

Of course, I’m not suggesting that the IBO rating should be your most important consideration when choosing a bow. On the contrary, it’s one of the last things I look at. My point is that if you want to get more speed out of your arrow, I would suggest you focus on increasing the power of your bow, rather than decreasing the weight of your arrow. So you can look for a bow with a higher IBO rating, more aggressive cams, and increase the poundage. I was in this exact situation with my Hoyt Charger. I was already shooting a heavy arrow, so if I wanted to get more KE, it had to be from increasing speed. So I worked the poundage on my bow up to its max of 60#. My new bow, a Prime Rize, is in 70#. This is specifically because I want more KE, but I also want to maintain some good speeds.

Afterward: Where To Start

Ok, so where should you start if you’re picking out arrows for your brand new bow? Or, if you want a more efficient hunting arrow?

First, do some research on different arrow manufacturers. Read some reviews, talk to pro shops, and do plenty of other research. Use the selection charts to determine which arrows fit your bow specifications. Look at the arrow weights. Determine your budget (I didn’t go into this, but basically, spend as much as you are able on arrows…generally, the more expensive they are, the more consistent and precise they are). IMG_3044 If possible, try shooting a few of them through a chronograph and do some calculations to compare the KE you’re getting out of each arrow. There are some other factors and calculations you will want to think about to maximize the efficiency of your bowhunting arrow as well (e.g. arrow length, F.O.C., broadhead weight, etc.). As with anything to do with archery, don’t discount your own intuition about which arrow feels most comfortable shooting, but certainly be confident in the numbers you are getting from your tests and trust those.

This is the fun part. Enjoy the shooting!