Mini 3-ring risers strong enough?

[BUBLHED 0]

I would like to get Mini 3 rings and louie loops. My question is at an exit weight of 245 lbs. would this be wise? Are there any louie loop risers for standard 3-rings? I know a rigger can make them but I'd rather just buy them pre-made.

I've read over some older posts on this and there seems at that time no definitive answer. I was hoping for any new information or personal exp. from someone in the know.

ATTACK LIFE ! IT'S GOING TO KILL YOU ANYWAY!!!!

[JustChuteMeNow 0]

Type 17 or mini risers have a breaking strengh of 2500 pounds while Type 8 risers have a breaking strength of 4000 pounds. Both are safe for skydiving applications. In other words a breaking strength of 2500 pounds is more than adequate.

Put another way if the force generated during a deployment would be enough to break a riser then it would almost surely incapacitate or kill the skydiver. This would be true even if Type 8 risers were being used.

Think of how stupid the average person is and realize that statistically half of them are stupider than that.

[hackish 8]

There have been many reports of type 17's breaking. I know there were some reenforcements made around the grommet areas where they were breaking. Key point take care of your gear and make sure you inspect it before jumping. I personally don't like the mini-risers but I've jumped them many times before. I don't think they're specifically unsafe unless damaged... duh.

-Michael

[BUBLHED 0]

I thought that the mini's strength was 3500 lbs. I am curious if any other "Big Boys" have had a cut away from a spining mal? As I understand that under the increased G's in can get really difficult with the Mini's. Bill Booth said that mini's were harder to make properly several years ago. Have they got them down now so that they are more reliable.

ATTACK LIFE ! IT'S GOING TO KILL YOU ANYWAY!!!!

[AggieDave 6]

I'm what you would call a big boy around 285-295 out the door. My last chop I was spinning on my back on my Velo 111 that was twisted up on me. Worked like a champ FOR ME but there are obvious reasons that standard risers and rings have an advantage.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[riggerrob 558]

".... Bill Booth said that mini's were harder to make properly several years ago. Have they got them down now so that they are more reliable.

[paulbo 0]

Just be sure to remember that any posted breaking strength assumes new and undamaged material. Either size will be fine, just make sure that you inspect them regularly; like you should be doing with all your equipment.

Paul

"It's like a hamburger, with cheese on it"

[gearless_chris 1]

I'm about 270 out the door now. I deploy at speeds well above what the canopies are rated for on a regular basis. I currently jump a Cobalt that opens so hard that sometimes my video cuts out. I had a riser strike break the aluminum box my camera is mounted in. I've broken several steering lines. My monarch blew out 3 cells, bent hardware, and tore stitching out of the harness. I have not had an issue with risers breaking yet, but there's still time . When my Monarch exploded (3 cells blew out) I had the reversed mini risers with the 3 rings on the back of the riser to eliminate the grommet hole, maybe that's why I didn't break a riser on that one. I have pictures of the canopy damage on this site.

"If it wasn't easy stupid people couldn't do it", Duane.

My momma said I could be anything I wanted when I grew up, so I became an a$$hole.

[kkeenan 13]

As Chris alluded to, the grommet hole is the key to the weakness. The rated strength of the webbing is not valid when you punch a hole in the middle of it and set a grommet. That was the source of the failures of the mini risers and is still the weakest point.

Kevin K.

_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

[gearless_chris 1]

I forgot to mention how awesome Louie Loops are! I got them when I ordered my new rig, then ordered a set for my back up rig. I don't know if the extra reach length made a difference for me, but the fact that they are ALWAYS open is worth the price. The dive loops on my old UPT type 8 risers are always folded flat against the riser and required some fluffing to get them open. They didn't always stay open either which sucks when you're planning on using them. Louie Loops rock, no fluffing, no searching for them.

"If it wasn't easy stupid people couldn't do it", Duane.

My momma said I could be anything I wanted when I grew up, so I became an a$$hole.

[BUBLHED 0]

Damn!!! Glad your not shorter now. I guess I'm safe with the minis, cool. Thanks to you all. I keep my gear checked religiously, until I grow wings that's all I've got.

Blue Skies

ATTACK LIFE ! IT'S GOING TO KILL YOU ANYWAY!!!!

[gearless_chris 1]

Quote

Damn!!! Glad your not shorter now. I guess I'm safe with the minis, cool. Thanks to you all. I keep my gear checked religiously, until I grow wings that's all I've got.

Blue Skies

Yes you do need to check them often. I'm a little paranoid since I have a RSL now. I also clean the cutaway cables once a month during the season.

"If it wasn't easy stupid people couldn't do it", Duane.

My momma said I could be anything I wanted when I grew up, so I became an a$$hole.

[d123 1]

This is an interesting subject.

Is it possible that the loop or the cut away cable could brake before the risers?

From the mechanical advantage point of view I'm aware of the following models:
- Type8 risers with large rings (200 to 1 m.a.)
- mini force (unknown m.a. but better than mini risers)
- mini risers (30 to 1 m.a.)
- reverse mini risers (unknown m.a. but lower than mini risers due to a missing lever effect from the closing loop)

Is it possible that on the models with lower mechanical advantage, for the loop or the cut away cable to brake before the risers (even if the riser has a hole in it)?

Lock, Dock and Two Smoking Barrelrolls!

[BUBLHED 0]

Don't really know. I really think that if properly maintained and not nicked in any way that the yellow cord would ever break from compressive forces. I could see it possibly flattening out at the closing loop location. I really can't see it breaking though. The red cable as I hear it is inharently weaker but still couldn't see breakage as long as it wasn't previously damaged. JMO as I'm not a rigger or engineer.

ATTACK LIFE ! IT'S GOING TO KILL YOU ANYWAY!!!!

[TonyJ 0]

its possible for the cutaway cable to get sucked into the grommet...tony

[gearless_chris 1]

Paragear lists Type 2 nylon as 400 lbs. strength. I don't think you can double the strength just because the fingertrap has double the thickness, the loop is only single thickness. 2 of my broken steering lines were in the center of the loop, so it must be weaker there. I doubt you're going to shear a steel cable with a piece of nylon.
How did you calculate the m.a.? The guy I was talking to from UPT at Rantoul said the mini force advantage is crap. Virtually insignificant leverage advantage, but with a much greater chance of binding. I wish I still had my reversed mini risers, it's been a while since I've seen how they route the loop. I thought it comes straight off the riser instead of making the 180 bend.

"If it wasn't easy stupid people couldn't do it", Duane.

My momma said I could be anything I wanted when I grew up, so I became an a$$hole.

[siddacious 0]

Quote

Paragear lists Type 2 nylon as 400 lbs. strength. I don't think you can double the strength just because the fingertrap has double the thickness, the loop is only single thickness. 2 of my broken steering lines were in the center of the loop, so it must be weaker there. I doubt you're going to shear a steel cable with a piece of nylon.
How did you calculate the m.a.? The guy I was talking to from UPT at Rantoul said the mini force advantage is crap. Virtually insignificant leverage advantage, but with a much greater chance of binding. I wish I still had my reversed mini risers, it's been a while since I've seen how they route the loop. I thought it comes straight off the riser instead of making the 180 bend.

I'm inclined to believe that you can theoretically double the rated number because the load is being by the two (2) sides of the loop.

A dolor netus non dui aliquet, sagittis felis sodales, dolor sociis mauris, vel eu libero cras. Interdum at. Eget habitasse elementum est.

[d123 1]

It's calculated in Poynter and Jumpshack has an article on m.a.

edit to add:
http://www.dropzone.com/gear/articles/The3RingWhatItIsAndHowIt.shtml
http://www.dropzone.com/gear/articles/Reversedvs.Non-ReversedR.shtml
http://www.dropzone.com/gear/articles/AnalysisofaRiser.shtml

Lock, Dock and Two Smoking Barrelrolls!

[gearless_chris 1]

That's awesome, thanks. I'm glad I don't have my reversed risers anymore. It was okay with my Monarch but not with my other canopies.

"If it wasn't easy stupid people couldn't do it", Duane.

My momma said I could be anything I wanted when I grew up, so I became an a$$hole.

[riggerrob 558]

The white loop is a simple 2:1 pulley, so it halves the side load on the (yellow) cable.
That is why reversed risers are not as easy to release.
Bill Booth once told me that he tested a variety of reversed risers and they failed at 20 to 80 percent of the strength of mini risers built to 3-Ring Inc.'s sepcs. Bill's biggest complaint was that no dimension have been published for building reversed 3-Ring risers.
The bottom line is that reversed 3-Ring risrs are not as strong.

[BKR 0]

We proceed to strength test with different risers years ago and the strongest mini riser tested was the PdF reversed one then the UPT and the weakest the Sun Path.
This was in 99 and I have the full report.

Jérôme Bunker
Basik Air Concept
www.basik.fr
http://www.facebook.com/pages/Le-Luc-France/BASIK-AIR-CONCEPT/172133350468

[erdnarob 1]

With your weigth I recommend you large 3 rings release since the force reduction factor is 200 (10x10x2) instead of 128 (8x8x2) for small ones. In case of cut away especially while spinning and experiencing a lot of G forces you will be more pleased to have large rings because of the force reduction.

Learn from others mistakes, you will never live long enough to make them all.

[BUBLHED 0]

I agree. I have always had the large rings and don't have any problem with them. I still think I've read somewhere that you can't get Louie Loops on type 8 risers but I'm not sure. If not I'll have something made. I had "Super Swoop Loops" made by my rigger on my other rig so no biggie.



S.S. Loops attach at the bottom of the front riser and run up through a ring at the top of the riser then to a hand loop. When you pull the loop the ring acts like a pulley and the riser collapses giving you a mehanical advantage when doing front risers. Greatly decreases riser pressure.

ATTACK LIFE ! IT'S GOING TO KILL YOU ANYWAY!!!!

[linebckr83 3]

Quote

The guy I was talking to from UPT at Rantoul said the mini force advantage is crap. Virtually insignificant leverage advantage, but with a much greater chance of binding.

www.flyaerodyne.com/download/miniforce.pdf

Seems pretty legit to me. Obviously a guy from UPT is going to say its crap, because the rig he is trying to sell you doesn't have it. What business doesn't work that way.

"Are you coming to the party?
Oh I'm coming, but I won't be there!"
Flying Hellfish #828
Dudist #52

[d123 1]

Am I doing the right calculation for the mechanical advantage?
674.4 pounds / 3,34 pounds = 201.79640718562874251497005988024 to 1 m.a. for the mini-force. That's better than the theoretical m.a. of the large rings.
Also the test done for the mini-rings shows a 75.605381165919282511210762331839 to 1 m.a. which is closer to what Andre posted (BTW thanks) than my 30 to 1.

Lock, Dock and Two Smoking Barrelrolls!