Sabre 2 with Lines trimmed to Sabre 1 spec

[dmhmetreo 0]

How much would this affect the performance on a sabre 2. I recently bought this canopy used and the seller said he was a rigger and relined it himself. I measured the lines and they are perfect to the sabre1 spec but this is different from the sabre2 spec. Not by much, the max difference I see in the 2 specs is about 1.75".

ref:
http://www.performancedesigns.com/support.asp?filter=sport

[Southern_Man 0]

Did he tell you he did that intentionally? Did he tell you why he did that?

I don't know the answer to your question but that just seems bizarre to me. I've only been rigging (and really even in the sport) a short time, though, so maybe I'm missing something.

"What if there were no hypothetical questions?"

[councilman24 37]

I doubt anyone besides PD could give you any answer because I doubt if anyone in the field as ever done it. And PD may not know either.

Is it really lined to different specs or is it just out of spec due to wear?

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[RiggerLee 61]

My first reaction is that the panel shape would not be optimized for that trim. The nose cut might also be less then ideal for that angle of attack. But that other wise it should behave more or less like a saber 1. Then I started thinking about the taper. It's not a lot but the cord length is shorter on the outer rib and with the saber 1 lines on there you would have a steeper angle of trim on the outer cells. So basically the outer parts of the wing are twisted nose down wards to a lower angle of attack. This bothers me a bit. I think you might be more prone to rolling under the outer cells if you let the canopy surge forward as you let off breaks or as you release break comeing out of a turn or in turbulance. the severity of this will depend on the taper ratio.

I obviously haven't jumped it but I would be suspicious of this canopy. I'd be carefull with it till you've really had a chance to play with, read that as "test", this canopy. But I'll go on record as thinking that this is not a good idea and you may have trouble with it.


Ok some time I'm a little to subtle. I felt the need to come back and add a translation. YOU'REGONADIEYOU'REGONADIE!YOU'REGONADIE! Ah, much better. I'll sleep easier now.


Lee

Lee
lee@velocitysportswear.com
www.velocitysportswear.com

[voilsb 1]

I have a friend who has done this with her Sabre2 150 for the past few years, and claims it is more true to the original Sabre2 trim. I don't know if this is true, but I do know that she likes how it flies and it doesn't appear to be dangerous for relatively conservative piloting. She doesn't do speed-induced maneuvers.

Brian

[RIGGER 0]

Hi

I would not jump it till talking to PD.

Few points:
The SA date of Mfg. & model: PO1 or PO2 ? look at the label.
Does the lines were made by PD ?
Which lines shows the 1.75" difference ?
No. of jumps on the line set ?

Don't be a TEST jumper - find out before use.

Cheers

[dmhmetreo 0]

Oh how I love DZ discussions. Thanks for the useful points. Thanks for the entertainment. I really like how one post had some intelligent points which were then totally diminished by summing it up in "your gonna die". I love it!

So in the end when I called PD they asked me if I was certain that it was trimmed to Sabre1 or just OOS. With about 200 jumps on the line set it is possible for a little deviation in the lines up to maybe 1" (says PD rep). The PD guys are awesome - the one I talked to also taught me how to spot the diff between spectra and vectran. So in the end I went back and for fun measured my previous canopy and found that the lines were very OOS. More like 10" OOS in some places. So if I was jumping that what does it really matter? In summary the canopy is great, flies fine, opens fine, etc. I guess it would have given me the best insight to just measure my old canopy first.

Out of this I made a spreadsheet for calculating OOS and comparing various trims on a sabre. I will clean it up and attach it if I feel so motivated....

[riggerrob 643]

If all the lines are 10 inches longer, no big deal.
The danger comes when you have a significant difference between the center-cell and end-cells.

I always start by measuring the difference across the left A-Lines. Quite often that is as far as I get before telling the owner that he needs to reline the canopy.