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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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.

Outdoor 30 er 15, Younger Edition

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The younger one wanted to sign up for the outdoor shoot.  The USAT style shoot has no category younger than Bowman.  As a Yeoman, there’s not really a division for her.  The Director of the Shoot decided to create a loophole.  Younger shooters could shoot a 15M target, but they would be doing it outside of the normal competition.  We had practiced 20M at our practice range and I thought it would work out.

It didn’t work out.

She didn’t want to be there and her head down photo above is only a snapshot of her attitude.  After the warm up practice rounds, she withdrew.  Archery and other things may be on hold for this one.  It was a frustrating day.

Outdoor 30, El Dos

The second round of the five part buckle shoot was scheduled over the Fourth of July weekend.  I would guess about half the number of participants as the Father’s Day buckle shoot.  It was a strange distribution of shooters.  Her mentor (pictured above) was the only Junior Female Recurve, meanwhile the Barebow division was full of all ages of shooters.  In her own division, there were the same number of kids as last time.

The other two photos are taken from a former teammate, Sara Martin.  In a time when everyone has a great 10 yard camera on their phone, Sara brings another perspective with a long lens SLR.

Conditions were the same, hot and windy.  She decided to wear her dress from Furry Feline Creatives.  I’m fairly confident she’ll never encounter another archer with the same outfit.

She stayed strong throughout the shoot and had enough energy during the elimination rounds.  She came up short against her principal rival and captured a second place podium finish.

Outdoor 30

First outdoor tournament of the year for the older one.  She is a “bowmen” class and that means she really can’t compete in the big national tournaments that have Cadet and Junior programs only.  Technically, she can shoot in those older age divisions, but the shooting distance starts at 60 and you have to pull a pretty big bow to shoot that distance.  Locally, one (or maybe two) of the JOAD clubs has set up an outdoor series.  This includes shorter distances for the younger divisions, including 30 for bowmen.

Like all archery events we have attended outdoors, you have to deal with the sun and the wind.  This was no different.  Our car thermometer said it was 101.  She had ramped down lessons over the last month, so this was her first event in at least a month.  She shot outside at the park and she got reps in on the side yard.  She used her new Easton outdoor arrows.  She ended up in third place.

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!

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Second (or First?) Rotational

After her own switch to the left, the younger one took part in her second tournament, but it could almost be considered her first since she is doing everything new.

They packed the young kids into one side of the range.  It was interesting to see them try to stay in their shooter’s box.  I suspect many of them shoot with a lot of space on the line at practice.  With her riser, new limbs, and stabilizer, she had a bigger presence compared to the compound shooters their little bows.

She doubled her score from the first tournament and took home first place and a new Hoyt cap.

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).