Forums: Skydiving: Gear and Rigging:
reversed 3-rings and triple risers

 


Kirils  (D License)

May 24, 2001, 6:32 PM
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reversed 3-rings and triple risers Can't Post

i just purchased an AR-11. It came with reversed 3-rings and
triple risers. Is it safe? I sent it back to AR for inspection and steering line replacement, but they said nothing about the risers.

Thanks!

Kirils

Skydiving is not a static excercise with discrete predictability...


riggerrob  (D 14840)

May 25, 2001, 8:27 AM
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Re: reversed 3-rings and triple risers [In reply to] Can't Post

Assuming good quality control, reversed 3-rings on three-leged risers are fine.
Reversed risers were popular in the early 1990s before we worked out all the bugs with mini risers.
Three-legged risers are designed for the hardest-core canopy pilots who want their canopies to spread a little more for flatter glide and more stability. Three-legged risers also reduce friction on the steering lines because they eliminate a corner.



Kirils  (D License)

May 25, 2001, 9:04 AM
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Re: reversed 3-rings and triple risers [In reply to] Can't Post

Thanks! A little peace of mind now....

Skydiving is not a static excercise with discrete predictability...


mikefarmer  (D 19948)

May 25, 2001, 11:16 AM
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Re: reversed 3-rings and triple risers [In reply to] Can't Post

Just curious, Reversed like integrity risers, or reversed like big ring on top???

Mike

Veni, Vidi, Velcro...I came, I saw, I stuck Around


miked10270  (D 10270)

May 25, 2001, 11:31 AM
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Re: reversed 3-rings and triple risers [In reply to] Can't Post

Hi there,

Reversed as in the rings sitting behind the riser (against the harness).

In the early days of Type 17 (skinny) risers, there was some concern expressed about loss of riser strength with the grommet hole for the loop. The answer offered was skinny risers without the grommet through the riser & hence the reversed rings.

This unfortunately resulted in a loss of mechanical advantage over & above the loss incurred with mini rings! In addition, several manufacturers grounded their reversed risers in the last 2 years (for various reasons).

Kiril,

Can I suggest that you identify the manufacturer of your risers & check with them if they still consider these airworthy!! Better safe than sorry.

Mike D10270.



mikefarmer  (D 19948)

May 25, 2001, 11:43 AM
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Re: reversed 3-rings and triple risers [In reply to] Can't Post

In reply to:
In the early days of Type 17 (skinny) risers, there was some concern expressed about loss of riser strength with the grommet hole for the loop. The answer offered was skinny risers without the grommet through the riser & hence the reversed rings.
OK, I believe these are called Integrity risers.


Mike

Veni, Vidi, Velcro...I came, I saw, I stuck Around


DBTECH  (B 21186)

May 25, 2001, 12:35 PM
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Re: reversed 3-rings and triple risers [In reply to] Can't Post

For the record, I thought some of you may have interest in this question asked on rec.skydiving. db

Jaime asks:

>>Can anyone tell me anything about integrity risers?
>>Thanks for your time.

Integrity risers were first dreamed up because of the fear of riser failure only on the side with an RSL connection, during a very fast/hard opening, which would result in a main-reserve entanglement.
(Yes, it has happened.

Integrity risers are built without a grommet in the riser for the cable loop. Instead, there is a tab on the ring side of the riser that has the grommet. Integrity risers are installed on the harness ring in reverse (riser rings toward rig). Integrity risers are stronger because of their absence of a grommet hole.

There are two negatives regarding integrity risers. The first is the fact that the loop mechanical advantage is close to half that of conventional risers, which in fact reduces the total mechanical advantage to close to half also. The reason that they have reduced mechanical advantage is because there is no longer a loop around the small ring, but a near straight line between the loop attachment point and the locking cable.

There is in fact recorded cases, where under a high G spinning malfunction, where the release cable was pulled into the grommet somewhat, due to the higher forces, which resulted in a very hard release cable pull. When you consider this factor combined with the high friction of soft housings, you can see the potential of a deadly combination.

This is not just my opinion, but is one shared by many in the industry.

As far as stainless housings, I recommend keeping them clean, along with clean cables with a little silicone applied. Regular maintenance will keep them at a low coefficient of friction.

The second negative is the possibility of not getting a riser release because of a combination of lower harness rings locations and a somewhat face to earth under a low drag malfunction. Rigs/harnesses made today are made with this in mind to assure high harness rings locations.
I do not use an RSL, but I do like the strength advantage of a hole-less TY-17 riser.

As far as a canopy with high spin rates associated with malfunctions being used with integrity risers, I myself have no problem with integrity risers, because of the factor of housing/cable maintenance.

I once had a very fast/hard, brutal opening on my Spectre 170 with integrity risers. When I examined the loop/grommet/cable point there was no evidence of penetration of the cable into the grommet, which in my opinion, gave me a better "feel" for the total mechanical system.

I recommend the use of the short metal excess cable housings installed in the stow channel in all risers, be it type 8 or type 17. These housings will prevent release cable capture/binding after a severe riser twist due to a severe canopy spin. 1/4" OD X 0.035" wall Teflon tubing works great also. One tack with Nylon wax cord 1/4"-3/8" from the inserted end holds it in place.

I'm not trying to put down type17 integrity risers, as I have used them myself.

Ultra blue skies,

Dave Brownell

DB Technologies

Mesa, AZ




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