Formula Limbs: Extracting Value

In a previous post, Formula fittings are compared to ILF. In this post, a deeper dive into the Formula limbs.

A 2009 Hoyt product catalog introduced the system

NEW PARALEVER MOUNTING SYSTEM

The Formula limbs innovative, all-new cross-carbon multi-laminates work in concert with the Paralever Mounting System and extended limb design to reshape the limb stress curve for unmatched smoothness before the shot. The Paralever mount also manages vibration after the shot, with more than 40% less limb stress in the critical riser interface area. The result: increased smoothness in the clicker zone and a substantial velocity advantage with ultimate accuracy. The Paralever mount also further reduces limb alignment tolerance, allowing for rock-solid alignment stability and 0.005” increment adjustment capability using the ultra-reliable Hardlock alignment module.

Formula system components feature two riser lengths and three limb lengths for combinations ranging from 66 to 72 inches in length, and from 22 to 50 pounds measured to ATA standards.

The Formula Series Limb Dampening Bushing allows the use of accessories like the FUSE Recurve Shock Rod or even a simple Doinker suppression mount – to absorb vibration before it gets to the riser. This patent-pending feature is exclusive to the Formula Series.

The Formula Patent

ABSTRACT
A traditional archery bow includes a handle assembly, a bowstring, and at least one connection apparatus. The handle assembly includes a riser, an upper limb, and a lower limb. The upper and lower limbs each include a proximal end connected to the riser and a distal end. The bowstring extends between the distal ends of the upper and lower limbs. The at least one connection apparatus is mounted to at least one of the upper or lower limbs. An accessory such as a bushing or stabilizer may be mounted to one of the limbs with the connection apparatus.

In my view, the two distinct features are:

  1. Longer fitting compared to the ILF
  2. Limb dampening bushing

Longer Fitting

The change in geometry on the Formula limb (about 1.5 inches longer) will change the physics of the limb. The longer working segment of the limb will change the drawing and loading characteristics of the limb. In theory, the total length of the limb could be made lighter since the thick, heavy part of the limb doesn’t have to be as long. Lighter limbs will change the energy dynamics of the bow in general.How would a normal human test this? It would require Hoyt to make identical risers in both the Formula fitting and the ILF (“Grand Prix”) fitting. Then, identical Hoyt limbs in both fittings and an incredibly robotic archer shooting statistically random sessions (hot, tired, indoor, etc). This would be fantastic, but unlikely since Hoyt doesn’t produce their high end risers in both fittings. They do produce the Horizon in both fittings. As a parent of a young archer, I struggle to think about the nearly robotic archer to launch and measure the results.

Limb Dampening Bushing

From Hoyt Patent

This is the second feature of the Formula is the the threaded socket (bushing) to allow a new class of dampener to attach to the limb and absorb vibration from the limb before it hits the riser. The patent illustration shows this example:

From Hoyt Patent

This sounds logical and it would be neat to see innovation in he limb dampening space.

Photo from Bignani Archery (Italy)

And here is an archive picture of Brady Ellison shooting Formula limbs with a dampener.

Photo from Wired Magazine

You can see the dampener highlighted in yellow.  There’s a special dampener on the back of the bow shown in blue.  I suspect that might be a Doinker.

In 2017, several years after the introduction of the Formula limbs, the market should have many options. Sadly, there are not a lot of market options. Is the market voting that this technology isn’t living up to the promise?

The dampener used by Brady Ellison appears to be a Sims Limb Saver Node.  It was released in 2010.  According to Lancaster, it has been discontinued.

discontinued

The FUSE Recurve Shock Rod also appears to be discontinued.

An interesting question remains.  If you attach something like the FUSE dampener to your limb, do you only attach it to the bottom limb?  Do you shoot with this apparatus on both limbs?  Does only the bottom limb produce vibration?  I guess the advantage of the riser based stabilizer is that it can take vibrations out from both limbs.

Bottom Line

If you are chasing the top of the line riser from Hoyt, it will be a Formula fitting riser.  The Hoyt engineering team may have found a way to get straighter and lighter limbs by changing the ILF into the Formula fitting.  Any benefit you receive from the Formula fitting will be wrapped up in total engineering of the premier equipment from Hoyt.  I don’t think you will be able to say the limbs were the single secret.

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Hoyt Grand Prix, ILF, Hoyt Formula – What Is the Difference?

Besides angering online archers, what is the difference between ILF, Grand Prix, and Formula limbs?

There are ILF limbs from SF Archery and Formula limbs from Hoyt.

Recurve bows are made in a take apart design. The International Limb Fitting or ILF was first designed by Hoyt in the 1980s. Before this time, manufacturers had different limb fittings that were not interchangeable. Today, Hoyt call this the ‘Grand Prix’ fitting.

ILF and Grand Prix are the same thing.

Hoyt evolved the Grand Prix design and created the Formula fitting. It is also a dovetail system. The slide-in attachment on a Formula limb is about two inches further away from the slot. As such the attachment portion of a Formula limb is about five inches while ILF is three and one half. Obviously, the physics have changed and Hoyt has probably found some benefits from this design besides a fitting that is exclusively theirs.

Formula and Grand Prix/ILF are not compatible.

Here is a Hoyt Grand Prix Horizon riser and Hoyt Formula limbs. You can see the compatible notch, but the ILF riser ends and the Formula limb is too long to attach.

Finger Tabs With Too Many Options

From what I can tell, the FIVICS “Saker” has become one of the most popular and imitated finger tabs.  Originally released as the Soma, the Saker comes in at least three models (Saker 1, Saker 2, and Saker3) and at least three materials (Aluminum, Brass, Carbon Fiber).

saker-fivics

The Saker 1 is on top (blue), the Saker 2 is on the bottom left (green), and the Saker 3 is on the bottom right (red).  Which one is right for you?  This is especially important in the age of online shopping and limited selection in retail.  Importantly, it’s not just the color (more on that later).

They are not named by “quality” either, the Saker 1 isn’t better than the Saker 2 or the Saker 3.  It’s more about the design.  The Saker 1 has more metal and sits back into your hand.  That triangle on the end may not be very comfortable for many shooters. There also appears to be some other accessory that can be added to the back triangle. The Saker 2 has less metal and the Saker 3 has even less metal.  It comes down to how much you like the extra metal and this other fact (that isn’t published on many retailer sites but is available on the FIVICS site ) — what is your preferred positioning of your fingers on the string regarding the load of drawing?

saker-angles

Model Index Finger Middle Finger Ring Finger
Saker 1 30 50 20
Saker 2 30 55 15
Saker 3 40 50 10

Besides the fit in your hand, this other bit of data may be an important decision making point. Kisik Lee in his book says the right distribution is 40, 50, and 10. That would make a good choice the Saker 3, particularly if the Saker 1 is uncomfortable.

Now, what color? Surprise, you don’t pick a color. You pick a size. But most of you are shopping online. What size do you need? FIVICS has put out this guide (PDF), but again, it’s not easy to find. My copy surfaced on a Slovakian site.

fivics-guide

You’ll note Dark Blue is XL and at the other end, Green is XXS. The guide may not be flawless, so I found this extra information.

fivics-saker-1-finger-tab-4-579-p

(From Online Archery Equipment in the UK)

Finally, there are three materials. The aluminum model is by far the most prevalent. It’s also the only one with color selections. The brass model is three times heavier than the aluminum model and that may be important for some shooters. The carbon fiber model is lighter and probably stiff than the aluminum model with less chance of deforming.

We ordered the Saker 3 and soon, she’ll be able to tell me how it is to shoot with it.

Returning to the Range

A month ago, the younger one had withdrawn from the shoot.  We returned to practice this weekend at our outdoor range.  She proclaimed she was so excited to be able to shoot again.  And overall it went really well.  She was appropriately distracted by various bugs and a fearless little bird she named “Tinee”, but she completed more ends than I expected.  We were out there for almost four hours because the older one was getting ready for her second state games.

We worked on form, as every archer does during every practice, or at least that is what every practice has been for these kiddos.  Maybe Mackenzie Brown gets to do something else with her practice time at this point.

Understandably, her form was a little rough.  I decided to use Hudl Technique with her.  I was hoping to slow things down so I could see it.  I’ve used Hudl with the older one and I also wanted to make sure the younger one knew she was special too.

It was easy to see at 1/4 speed even if it is hard to see your iDevice with full sun.  I shared it with her and she felt like she could keep her bow arm extended and work on her draw arm elbow.

Meanwhile the older one was getting her site ready for 30-20-10 distances that the next tournament uses.  She was doing her sport and I didn’t have to pay too much attention other than recording her site positions.

Having a camera helps, but we also record them in her archery journal so that when we get to a tournament, we have backups.

She really likes this Shibuya site.  There are more expensive models, but this one works for her.  Since she started using it, we are both seeing more of them around, probably some sort of cognitive bias.   At Salt Lake, Steve Anderson spoke to the archers at breakfast.  Later, we saw he was shooting a Shibuya too.

archeryworldcup2016stage2medellin958vtdackx6x

There summer is winding down.  School starts again in a few weeks.  That means the outdoor season is winding down and the indoor season will be ramping up (with a lot of overlap).  I think the Byrds sing a song about this.

Bowmen Year End

So many things for this archery season.  She added a sight.  She added a stabilizer.  She got a new, heavier poundage bow.  She got a new plunger.  She went out of state.  She shot 40cm.  She made an archery-BFF.  She got outdoor arrows.  She got a new practice bow.  She is rebuilding her shot sequence.  She survived some friends leaving her team.  She got a new mentor.  She trained with and survived her sister.  She started shooting with her mom.  She fought with and then made up with her dad.

She has worked on her form since SLC, but early in the tournament, her fast shot returned.  She fought it some and went with it on other ends.  She improved over SLC, but didn’t reach some of the scores from early in the season.

Overall, the season isn’t easy to chart.  With her equipment changes and target size changes, it’s not easy to compare scores from 40cm to 60cm.

It was a year of some podium finishes, some off days, a lot of practice, a lot of work, a lot of stress, and a lot of growth.  She has more of the same in front of her for several years in and out of archery.  Keep at it kiddo.

Her third place finish!

IMG_4928

Outdoor Arrows for Shooting 30+

Her coach suggested some outdoor arrows. That means breaking free from our standard aluminum arrow.  Indoor arrows can have a wider tube (“shaft”) and for recurve use feather fletchings vs plastic vanes.  This could mean soliciting lots of opinions and getting advice from different range staffers or messaging with Lancaster Archery.  Instead I took a recommendation from the excellent Easton Archery Podcast and decided to focus on the Carbon One. Her coach agreed, but now more questions. Arrows aren’t like picking a soccer ball, you could select the Adidas Tango and then the next choice is color and size.  With arrows, the dimensions of choice include size, shaft weight, spine @28″ span, length, fletchings, and point weight.  She is not ready for a clicker (which assists in the shot sequence and will alter the arrow length), so we don’t know how long the arrows should be nor the shaft weight.  These will be the first two questions a tech will ask you.  Her coach let her try some different sizes Of Carbon Ones, but they were mostly cut to work with clickers. When she shot these short arrows, her coach said they were “porpoising”, which means wavering up and down. That means longer arrows are required.

It is hard to avoid the complexity of the Easton Arrow Selection Chart.  Despite a lot of work to make the chart user friendly, you have to know a lot about you, your bow, and your setup.  This is a moving target for a young archer.

The Easton Selection Chart

Her coach suggested getting a couple of weights and testing them out.  We have three each of 1000 and 1150 with the recommended tip.  The Easton tip is 70, 80, or 90 points, which is a unit of measure for weight.  The tip breaks off at various places to change the weight.

carbon-one-tip

They are attached with hot melt which is a glue that is applied with heat versus a cement glue.  The plastic vanes are attached with a slight offset.


The only thing in common with the aluminum arrow is the Easton G Nock (no pin).

These thinner arrows shoot faster (they stick into the bale further) and shoot farther (her misses were further down the range).  This sounds complicated, and we are at the novice stage.  I suspect this is why there is a lot of “follow the leader” in arrow selection or “buying from the top of the list” – if you notice that Brady Ellison uses the Easton X10 (their high price arrow), and you purchase it, you don’t leave room for too many excuses with your equipment.

 

Meet The Risers

risers

What is the difference between a riser of one family and a riser of another family?  I don’t know if it is tremendously different as a purchaser of equipment.  Here’s the Prodigy XT and the Horizon Grand Prix.  If we don’t look at their profile with different lace structure patterns, I see a lot of similarities in the arrow platform, the stem, and the thickness of the bow.   I understand that the Prodigy has a variation of ILF that I haven’t quite understood.  I miss the old apple logo from Hoyt (which may be part of Easton’s old offerings, more here).

Too Much Gear

The younger one is doing pretty well shooting with her (left) hand me down kit (Hoyt Grand Prix Horizon Pro 25″ – still available even with model year turn over) and with a splash of black accessories, the bow doesn’t look like it used to when the older one used it for a palette of ocean colors.

But wait, who is that in the background?  Have we found a home for her right handed bow?