ridetofly 0 #1 June 28, 2002 Hey everyone, I was wondering if someone could tell me the biggest difference/advantage/disadvantage there is between a 7 cell and 9 cell canopy. I'm sure there is a lot of other factors that also come into play, but in general can you help me out? Hope everyone is enjoying there Friday! Aaron Live as you will want to have lived... Quote Share this post Link to post Share on other sites
freeflir29 0 #2 June 28, 2002 I just flew a 7 cell for the "Pre-second" time last weekend. I normally jump a Stilletto 170 and a friend wanted to jump it. So I took his Spectre 170 for a ride. It sniveled nice but I didn't find it excessive at all. About the same as my Stilletto. However, it was much more stable in the snivel. It was fairly "ground hungry" but also seemed to glide nicely in rear risers. Carved great but the toggle pressure was pretty high. Surfed nice. I guess the big differences are: A 7 cell tends to be trimmed "steeper". IE DOesn't glide as far as a 9 cell. Openings are "Slow" according to some. I found it about the same as my Stilletto. Toggle pressure is higher on a 7 cell. Umm....thats about all I can think of. I liked the Spectre. Didn't turn quite as fast as my Stilletto but is a really solid canopy in turbulence. Winds were probably 15 MPH or so when I landed and it was ROCK solid even in a carve. Quote Share this post Link to post Share on other sites
landmissle 2 #3 June 28, 2002 Clay, pretty much hit it on the head. In general, a 9 cell has a flatter glide than a 7 cell. What this means is that for a given unit of descent, the 9 cell will travel further horizontally than a 7 cell. One is not necessarily better than the other. It's a matter of style and preference. The difference between the two most dramatically makes it self appearent during the landing flare. A 9 cell has a "flatter approach" while a 7 cell comes in "steeper". So in general, a 9 cell can give a nicer swoop but a 7 cell can be made to sink easier. Many folks, like 9 cells for the "swoop" capacity and others like 7 cells because they can be easier for accuracy landings. That's not to say that you can't swoop a 7 cell or land a 9 cell with accuracy, it's just the general charectoristics of the canopies. If you're undecided about what you prefer, diffently demo both types from various manufactorers, to get a clearer idea of how they handle. I've not noticed that one type snivels more than the other. I will say that most 7 cells that I've flown tend to open more on heading than 9 cells but that's more due ( I suspect...) to the more elliptical nature of the 9 cells as compared to the 7 cells I've flown. A notable exception here is the "Diablo" which is a very elliptical 7 cell ( a fun canopy by the way, but I still prefer 9 cells.) Hope this helps!Feet up, heads down, blue skies WWOD? Landmissle Quote Share this post Link to post Share on other sites
PhreeZone 15 #4 June 28, 2002 >Openings are "Slow" according to some Thats weird, then why are base canopies and reserves 7 cells? A canopy can be designed to do what ever the intended purpose is, but the glide rate is dependent on the aspect ratio, the smaller the ratio, the less the glide. A spectre is way up there on the 7 cell ratio'sYesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
skybytch 259 #5 June 28, 2002 Like Clay said, 9 cells have a "better" glide ratio than 7 cells. A 7 cell will come in steeper than a 9 cell will; a 9 cell is likely to get you back from a long spot better than a 7 cell. I jump a 7 cell because I find it to be easier to land and easier to be accurate with. Openings have more to do with the shaping of the canopy and how it is packed than the number of cells. I've been whacked by nine cell rectangular canopies many more times than by seven or nine cell "tapered" or "semi-elliptical" canopies. Quote Share this post Link to post Share on other sites
polarbear 1 #6 June 28, 2002 You are right in saying that 7-cells tend to glide more steeply. That is a function of the aspect ration, not neccessarily line trim. 7-cells do not necessarily have to be trimmed steeper than 9-cells. Toggle pressure is also not neccessarily higher on a 7-cell...that is mostlty a function of the planform shaping and the steering line setup (cascade lengths, where the lines are attached to the canopy, how many are attached to the canopy...). Other characteristics of 7-cells are that they tend to roll in to a turn faster, but they have a slower ultimate rate of turn. The tend to be more stable and open on-heading. Given equivalent wing-loadings, 7-cells will also tend to malfunction less violently. They are also less prone to line-overs. The stability, opening, and malfunction characteristics is why they are often chosen for reserves. Phreezone: Base canopies and reserves open fast because of the way they are packed (nose flaked open and exposed to airstream) and because the sliders are often small, have holes cut in them, or are missing completely. "Holy s*** that was f***in' cold!" Quote Share this post Link to post Share on other sites
freeflir29 0 #7 June 28, 2002 QuoteOpenings are "Slow" according to some I threw that in because most of the 7 cells I see being flown today are either a Spectre or clone thereof such as an Omega. They are known for slow openings but after jumping that one I don't know why. It didn't snivel any longer than my Stilletto on a good day. Quote Share this post Link to post Share on other sites
skybytch 259 #8 June 28, 2002 QuoteIt didn't snivel any longer than my Stilletto on a good day. Right. And Stiletto's are known for slow openings. Try comparing a Spectre opening with the opening on an all F111 seven cell like a Fury or PD160, or an original Sabre with a Sabre2/Hornet/Safire... the difference is in the shaping, not the number of cells. Quote Share this post Link to post Share on other sites
freeflir29 0 #9 June 28, 2002 QuoteTry comparing a Spectre opening with the opening on an all F111 seven cell like a Fury or PD160, True...my PD 190 did tend to open faster than a Spectre. Although once I learned to Pro Pack I got it sniveling quite nicely. Probably 4 seconds or so of sniveling. The DZO at Rome packed it once and snivelled for 6+ seconds OUT OF THE BAG. That was silly for that canopy!!! Quote Share this post Link to post Share on other sites
billvon 2,396 #10 June 28, 2002 >I was wondering if someone could tell me the biggest > difference/advantage/disadvantage there is between a 7 cell and 9 > cell canopy. About the only one that's hard and fast is that 9 cells tend to glide better; 7 cells handle steeper approaches better. Everything else depends on design (i.e. there are fast turning 7 cells and doggy 9 cells.) Quote Share this post Link to post Share on other sites
ridetofly 0 #11 June 28, 2002 Thanks for the info everyone, enjoy you weekend!Aaron Live as you will want to have lived... Quote Share this post Link to post Share on other sites
skymedic 0 #12 June 29, 2002 look what happened to anne(fallinwoman) last week on a spectre though....BANG open...HARD broke lines and got a cutaway..Just to say..that just cause it's made to open slowly doesn't mean it always will...alot more than just design goes into the buttery openings.... Marc otherwise known as Mr.Fallinwoman.... Quote Share this post Link to post Share on other sites
skybytch 259 #13 June 30, 2002 Line dump can happen on any canopy. Which is why it's important to be sure your stows are tight... Quote Share this post Link to post Share on other sites
Nightingale 0 #14 December 15, 2003 first time I jumped a spectre (jump #11) I almost grabbed for my handles because the snivel felt so much longer! I gave it another few seconds though, since I'd pulled high, and it opened no problem. Was just slower, but a very nice opening. Quote Share this post Link to post Share on other sites
ianmdrennan 2 #15 December 15, 2003 not to sidetrack the thread but lets not forget about the bandless bags out there. I think it's safe to say that line dump doesn't happen (at least in the manner it's traditionally thought of), now if the canopy comes out of the bag before line stretch....well that's a whole new story. Blue skies IanPerformance Designs Factory Team Quote Share this post Link to post Share on other sites
skygod7777 0 #16 December 15, 2003 Quotenot to sidetrack the thread but lets not forget about the bandless bags out there. I think it's safe to say that line dump doesn't happen (at least in the manner it's traditionally thought of), now if the canopy comes out of the bag before line stretch....well that's a whole new story. right, i have taken my canopy, just put in the first 2 lockin stow and free stowed the rest and couldn't tell a difference in the openings from when i stowed all the line but about a foot. i usally leave about 2' or 2.5' from my last stow. but like you said, if the canopy gets out of the bag before the rest of the lines let go, then you have a problem. but the lines letting lose before the locking stows, well that makes almost no difference. later Quote Share this post Link to post Share on other sites
Jimbo 0 #17 December 16, 2003 Quoteright, i have taken my canopy, just put in the first 2 lockin stow and free stowed the rest and couldn't tell a difference in the openings from when i stowed all the line but about a foot. Agreed. I've been leaving 6 to 8 feet of unstowed line lately (maybe more) and my openings are just fine. I've also stowed just the locking stows and had great openings. - Jim"Like" - The modern day comma Good bye, my friends. You are missed. Quote Share this post Link to post Share on other sites
DJL 232 #18 December 16, 2003 Hey guys, I'm starting a new thread for questions about line dump and bandless stows. Will edit to link. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=812398;#812398"I encourage all awesome dangerous behavior." - Jeffro Fincher Quote Share this post Link to post Share on other sites
