Forums: Skydiving: Gear and Rigging:
Need new risers - any recommendations?

 


Maxx  (D 9594)

Jan 8, 2013, 8:42 AM
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Need new risers - any recommendations? Can't Post

Hello,

I have a Teardrop SF and need new risers, because the rig came with triple risers and now my new slider grommets are smaller, so that the old triple risers hardly fit through. I now have a Crossfire2 119 and a little swoop ambition here and there, but nothing serious.
Dive loops are a must.
Any recommendations which risers I should get? What is the right length? I just wanted to research a bit, before I consult my rigger..

Thanks,
Max


phoenixlpr  (D 3049)

Jan 8, 2013, 8:48 AM
Post #2 of 15 (2274 views)
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Re: [Maxx] Need new risers - any recommendations? [In reply to] Can't Post

Not longer you can reach Wink


piisfish

Jan 8, 2013, 8:49 AM
Post #3 of 15 (2272 views)
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Re: [Maxx] Need new risers - any recommendations? [In reply to] Can't Post

I like my risers with "regular" mini rings, but with PdF style toggles, long enough so I don't have my arrms bent when grabbing the top of the riser


dpreguy  (D 835)

Jan 8, 2013, 9:14 AM
Post #4 of 15 (2238 views)
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Re: [Maxx] Need new risers - any recommendations? [In reply to] Can't Post

Consider the length too. I have been going to shorter risers (16 inch) for years. Even though I have long arms I still like the shorter risers. Easier to get to the toggles and the slider. By the time your body slumps in the harness after opening shock, and you have a couple of inches or more of air over your shoulders, standard length risers are sometimes a stretch. This is just my personal preference, and I have seen no reason for myself to go back to standard length risers. Maybe hang yourself in your own rig in a suspended harness set up and see what length is good for you.


JohnSherman  (D 2105)

Jan 8, 2013, 10:52 AM
Post #5 of 15 (2162 views)
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Re: [Maxx] Need new risers - any recommendations? [In reply to] Can't Post

Quote:
Any recommendations which risers I should get? What is the right length? I just wanted to research a bit, before I consult my rigger..

Riser lengths should be specified by the canopy manufacturer but rarely are. The Arc of the canopy and therefore the shape of the skins are dependant upon the length of the risers and lines as they are the radials of the canopy.

As to reach: Judging the length of the risers by reach is futile if you do not consider the riser mounting point on your harness and its relationship to your body. I like a lower mounting position as it sits me in the harness, not hang me by the top of my shoulders.


dpreguy  (D 835)

Jan 8, 2013, 10:11 PM
Post #6 of 15 (1976 views)
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Re: [JohnSherman] Need new risers - any recommendations? [In reply to] Can't Post

Riser length has nothing at all to do with the arc of a canopy if your slider stops at the connector links- soft or rapides. The slider width, determined by the manufacturer is what determines the arc of a canopy if it stops at the slider stops at the links. If your slider stops at the links, your risers could be 10 feet long and the arc of the canopy will remain the same.

(Of course, if you pull the slider down behind your head, then yes, the arc will be slightly changed with different length risers, and even your chest strap tightness if it is a wide slider)


bofh  (D 13995)

Jan 9, 2013, 6:24 AM
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Re: [piisfish] Need new risers - any recommendations? [In reply to] Can't Post

In reply to:
I like my risers with "regular" mini rings, but with PdF style toggles, long enough so I don't have my arrms bent when grabbing the top of the riser

I don't like PdF's risers, but their toggle mounting is the best!

I got myself a pair of vector 25" risers with Louie Loops and had chuting star do the "russian mod" on them - installing PdF style toggles (from Paraavis) and I'm really happy with them.

See http://www.chutingstar.com/...paraavis-pin-toggles for more info (check under the expert advice).


jerolim  (F License)

Jan 9, 2013, 6:46 AM
Post #8 of 15 (1908 views)
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Re: [dpreguy] Need new risers - any recommendations? [In reply to] Can't Post

Riser length changes force distribution ratio between AB : CD lines ! For example if this ratio is 60:40 with 20 inch risers (60 percent of mass is on A&B lines) it will be different if you use 25 inch risers. Canopy will be more loaded on C&D lines than usual. Such canopy would fly less steeply. For example Eiff Classic specifies riser length for their canopies.


piisfish

Jan 9, 2013, 7:04 AM
Post #9 of 15 (1896 views)
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Re: [bofh] Need new risers - any recommendations? [In reply to] Can't Post

In reply to:
I don't like PdF's risers, but their toggle mounting is the best!

I got myself a pair of vector 25" risers with Louie Loops and had chuting star do the "russian mod" on them - installing PdF style toggles (from Paraavis) and I'm really happy with them.

See http://www.chutingstar.com/...paraavis-pin-toggles for more info (check under the expert advice).
thanks for that info. I had mine get such a modification by GrandMasterRigger Colin Thompson in Empuriabrava Smile


dpreguy  (D 835)

Jan 9, 2013, 7:46 AM
Post #10 of 15 (1877 views)
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Re: [jerolim] Need new risers - any recommendations? [In reply to] Can't Post

Not if the slider stops at the connector links.

However, if the slider is effectively eliminated, by pulling it behind your head, then you are correct - it will change the flight charcteristics.

I have a large canopy demo rig with a separable slider. When I separate it after opening, my chest strap is tighter. (of course) and when I loosen the chest strap, the angle gets even bigger.

I fly a stiletto and love my 16 inch risers. I have slider stops at the links.

Whatever risers you buy, you still have to be able to easily reach the toggles. That's about it. If you have to lunge to get to your toggles, they are too long.


mark  (D 6108)

Jan 9, 2013, 3:23 PM
Post #11 of 15 (1785 views)
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Re: [jerolim] Need new risers - any recommendations? [In reply to] Can't Post

In reply to:
Riser length changes force distribution ratio between AB : CD lines ! For example if this ratio is 60:40 with 20 inch risers (60 percent of mass is on A&B lines) it will be different if you use 25 inch risers. Canopy will be more loaded on C&D lines than usual. Such canopy would fly less steeply. For example Eiff Classic specifies riser length for their canopies.

Ok, I'll bite. How much does the angle of attack change if the risers go from 20" to 25"? Alternatively, how much does the force distribution change for such a change in riser length?

Mark


jerolim  (F License)

Jan 10, 2013, 2:04 AM
Post #12 of 15 (1723 views)
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Re: [mark] Need new risers - any recommendations? [In reply to] Can't Post

In reply to:
In reply to:
Riser length changes force distribution ratio between AB : CD lines ! For example if this ratio is 60:40 with 20 inch risers (60 percent of mass is on A&B lines) it will be different if you use 25 inch risers. Canopy will be more loaded on C&D lines than usual. Such canopy would fly less steeply. For example Eiff Classic specifies riser length for their canopies.

Ok, I'll bite. How much does the angle of attack change if the risers go from 20" to 25"? Alternatively, how much does the force distribution change for such a change in riser length?

Mark
I agree change will be minimal. But if you go from 20" to 25" risers, canopy will fly slightly more steeply with more force on front lines. This is from eiff manual :

Risers

The angle of incidence of a canopy is set by the suspension geometry (we often call it the "line program") as measured from the bottom of the canopy, through the keel or flare, including lines, connector links and risers, down to the "node" point of the risers that is, to the point where the risers "split" into front and back risers, just above the 3 ring confluence wrap.

The suspension geometry of the Classic is based on 16 inch (40 cm) risers, measured from the top of the riser to the top of the confluence wrap. If you use longer risers, the center of gravity will move forward. The canopy will fly more nose down, and will be more difficult to stop. If you use shorter risers, the center of gravity will move aft. The canopy will fly more nose up, stalling with less brake deflection.

Risers are considered part of the harness, and are provided by your harness/container manufacturer. Therein lies a potential problem. If your system comes with very long (20") or very short (12") risers, your Classic will not fly as designed. The maximum variance from the 16" riser length figured into your Classic line program is plus or minus 2 inches (+/ 5cm).


mark  (D 6108)

Jan 10, 2013, 4:35 AM
Post #13 of 15 (1697 views)
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Re: [jerolim] Need new risers - any recommendations? [In reply to] Can't Post

In reply to:
I agree change will be minimal. But if you go from 20" to 25" risers, canopy will fly slightly more steeply with more force on front lines. This is from eiff manual :

<snip>
Risers

<snip>

I read that. I'm not convinced that difference will be noticeable after taking into account variations like canopy speed, load drag, density altitude, and Coriolis effect. Using your own canopy as an example, exactly how much change in riser pressure would there be by switching to 25" risers. Or, exactly how much change in the angle of attack would there be?

Mark


jerolim  (F License)

Jan 10, 2013, 7:18 AM
Post #14 of 15 (1681 views)
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Re: [mark] Need new risers - any recommendations? [In reply to] Can't Post

In reply to:
I read that. I'm not convinced that difference will be noticeable after taking into account variations like canopy speed, load drag, density altitude, and Coriolis effect. Using your own canopy as an example, exactly how much change in riser pressure would there be by switching to 25" risers. Or, exactly how much change in the angle of attack would there be?

Mark

I think you can get ratios by measuring (A lines + riser length) : (C lines + riser length).
Ill use metric system as I am from Europe,..
For example if your A lines + risers = 400 cm long
And your C lines + risers = 600 cm long
400 / 600 = 0,6666 ratio. This would be 66% of weight on front risers.

If we take 5' (12 cm longer risers)
Now we have 412 / 612 ratio = 0,673 witch is very similar to original ratio.

So I think that this difference is hardly noticeable on any canopy.
I did't experiment with high-performance canopy, I have jumped with Classic with shorter risers (and normal ones) and it is hard to tell if it is little slower on short risers,..


airgord  (D 15258)

Jan 13, 2013, 2:42 PM
Post #15 of 15 (1527 views)
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Re: [mark] Need new risers - any recommendations? [In reply to] Can't Post

Coriolis effect?



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