Design features that affect reserve extraction forces

[Deimian 43]

In another thread the tightness of reserve trays pop up again. I wonder what are the opinions of everyone on that topic. So the question is: Which design features make a container less restrictive once the RPC is out? Examples?

Racers will come on top of the list, I guess, due to the lack of stiffeners and closed corners.

What about the others?

Does a wide top flap close to the yoke make some containers more prone to increase the extraction forces (since the reserve tray is more enclosed)? Rigging Innovations and Sunrise Manufacturing rigs are two examples that come to mind. Is this true for both? Or for none? What about other examples that have this characteristic?

Do square sewed corners affect extraction forces? Which containers have this kind of corners in the reserve tray and which don't?

What about riser covers? Which designs hinder the extraction of the reserve? Is having secondary riser covers like Vectors good or bad for this?

What about other parameters? Which rigs use too many stiffeners in delicate places? Can the design of the freebag affect this? Can the placement of the AAD pocket affect this (I guess in the wall that separates the reserve tray from the main tray it will increase the friction, whereas in the bottom of the tray it wouldn't)?

Please note that the target of the thread is to discuss design features, not having a brand war.

[riggerrob 643]

The more stiffeners, the slower the free-bag extraction.
The longer the stiffeners ....
The wider the stiffeners ....
The tighter the corners ...
The more flaps above the free-bag ....
The narrower the container ...
The farther that riser covers overlap the top of the free-bag ...
The more tuck tabs ...
The more Velcro ....
Top flap stiffeners have greater affect than flap width.

If stiffeners in side flaps are longer than the diameter of the pilot chute cap, they might slow deployment.

Cypres pocket makes little difference. Since the d-bag's axis of rotation is close to the pocket, there is little risk of interference. Only the Strong Dual Hawk Tandem still has the AAD pocket in the pack tray, because of cable length issues.

[NV1 0]

just like riggerrob wrote...

the more stiffeners the worse is your extraction time.

Kickerflaps are a big issue in my opinion. Mostly when you have a Container that has 6 flaps (or more).
The Container designers make the stiffeners too wide, so that the plastic gets in contact with the side flaps when your freebag gets lifted out of the pack-tray.

[piisfish 140]

Deimian

In another thread the tightness of reserve trays pop up again. I wonder what are the opinions of everyone on that topic. So the question is: Which design features make a container less restrictive once the RPC is out? Examples?

Racers will come on top of the list, I guess, due to the lack of stiffeners and closed corners.

What about the others?

Basik Advance Out / Basik Seven. Very unrestrictive.

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[Deimian 43]

riggerrob

The more stiffeners, the slower the free-bag extraction.
The longer the stiffeners ....
The wider the stiffeners ....
The tighter the corners ...
The more flaps above the free-bag ....
The narrower the container ...
The farther that riser covers overlap the top of the free-bag ...
The more tuck tabs ...
The more Velcro ....
Top flap stiffeners have greater affect than flap width.

Well, all that is somewhat obvious . I intended to get a deeper discussion to try to extract a bit the knowledge that all of the riggers out there have, but is not written anywhere. Something like:

"Brand X extended the sides of the container towards the RPC to cover the risers when they go down the main tray at the sides of the reserve tray. In my opinion, in the case of a total malfunction, this can cause a larger extraction force than brand Y solution, that used secondary riser covers that do not slow down the extraction of the free bag."

Or

"The way brand Z sewed their corners is better because it is down in an angle that do not enclose the freebag, but as a result they had to change whatever other feature that causes whatever other effect".

Or

"Tuck tabs in container W are too long. That protects better the risers, but increase the extraction force. Instead, brand M uses a different shape that is equally effective but......"

Basically discuss the trade offs of the different design decisions that affect extraction force. That was my idea of the thread, but maybe it is overly ambitious. Possibly it is also a bit too much to expect to get that kind of knowledge for free and without spending years and years on a rigging loft. But I think it would be an interesting discussion for everyone, maybe I am wrong. Maybe a better way of looking at it would be to explain why everyone thinks that each brand is better than others in this regard, but then for sure it will end up in a brand war :-P.

[Deimian 43]

piisfish

Basik Advance Out / Basik Seven. Very unrestrictive.

That's what I thought when I saw them for the first time! I wonder why nobody else follows the same approach. What are the downsides to it? For those who are not familiar with that design: Those rigs have the RPC partially exposed, and hold in place by just a couple of flags (I think just 2). What looks like the side flaps is the freebag, wrapped in cordura.

[sundevil777 102]

My memory is that the Basik has upper corner features that are specifically designed to overlap the corners and retain the free bag. Perhaps it retains it just enough, or perhaps it retains it too much? Hopefully those with first hand knowledge can say it is good.

It seems that there is a general acceptance that among rigs where the problem is perceived to exist, the larger sizes are less affected.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[hackish 8]

While the TSO process is far from 100% perfect you can be assured that the manufacturers of TSO'd rigs had to do some testing to show that the reserve deployment happened fast enough.

I like is to stay with one of the larger brands because you know that the companies themselves were financed well enough to afford a good testing program and that they have enough test jumps, users and reserve rides that if there was a significant problem it would have already been found and reported here.

-Michael

[Hooknswoop 19]

Isn't restricting the free-bag from coming out of the container a good thing? Friction holding the free-bag in the container ensures the deployment sequence happens in the correct order.

This is the same for a main. You want the bag to stay in the container until pulled out by the pilot chute.

The issue then becomes how much friction? You want some, but not too much. How much is the minimum and how much is too much?

If I was on my back, at terminal+, I would want a lot of friction holding the free bag to prevent that bag going one way while the reserve PC went to the other. I want the free bag staying in the container until the reserve PC pulls it out.

If I was on my belly, sub terminal, I don't need very much friction holding the free bag at all. It just slows the reserve deployment and I'm not worried about the free bag leaving the container too soon.

Very complicated question, I think.

Derek V

[skydiverek 63]

Staging/hesitator loop solves that. Kind of like on Strong Tandem, or on Sigmas now.

[piisfish 140]

skydiverek

Staging/hesitator loop solves that. Kind of like on Strong Tandem, or on Sigmas now.

or on the Basik/Advance since the beginning.

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM