Basejumper.com - archive

When im back home jump a lot of lower stuff and recently have decided to buy a "low specific" (made with with ultralight material replacing the 0-3 parts, but that's a different subject entirely) canopy and was hoping to get some advise/comparison on Fox XS and OSP.

A few things in specifically I'm interested in for comparison are as follows but all opinions are welcome

1 versatility
2 performance on low free fall
3 performance on SL and DBA
4 pressurization times
5 advantages/disadvantages of the foxes oversized vents

A few other things I just want to throw out there in case it effects anyone's advise. It will not be my only rig, I have a few others, but I live on the road and don't have a car so some versatility would be nice if I am limited on how many rigs I can carry to a perticular place, but not to the extent of sacrificing what I'm buying the canopy for, sub 100' DBA sub 160' SL and sub 240' FF. Also price is a bit of a factor, with both canopies being made from ultra light 0-3 cfm, the OSP comes in at 2212$ and the fox XS 3162$.

Cheers guys, any advice at all helps

I've had a stand-up landing from a 125' SL w/ my FoxXs. Doesn't really seem to open any higher, but it's presurized and flying a lot faster.

The same jump with my Blackjack was much more PLF.

Also done a 205 FF w/ it with satisfactory results.

I have no first hand experience, but I recently witnessed a friend freefall our local 170ft E. It appeared to open near/slightly lower than a typical SL opening, and landed in the same general area that the SL'd canopies land. A couple spectators thought he was tied in. It opened much higher than I expected.

No first hand experience with the Fox, But have made quite a few jumps on my osp. I like it, but not a whole lot. I have made about 50-60 jumps on it, and I still prefer my Troll over the OSP. I am weighing in a little high on the osp (.73 wing loading), but it seemed very hard to get the brakes to be set to very slow forward speed on opening. In fact I had to set them so deep that I cannot use a tailgate anymore because the tail comes all the way down to the lock and stow... Have to use a tape tailgate now...(With A higher wing loading I understand that its going to be deeper to get the thing to slow down, but with my troll its no problem to get it to slowly back up on opening) The one thing I will say is with the extra stabilizers it seems to sink much more stable than my troll. Not any deeper or steeper, just more stable. There is no rocking back and forth when you get it going real slow. The pressurization is very good and consistent. I am afraid to take the thing terminal after I got spanked pretty good with a two second slider up delay off the Perrine...For what its worth, that's my 2cents... The attachment is of my canopy packed up, before I would "Pull the tail down" ... As you can tell there is no pulling the tail down because of how deep the brakes are. This setting still has forward movement on opening.

I jumped my OSP once on terminal jump with big mesh slider. It opened very well, not hard but still very fast, I'd say way more comfortable than my other two trolls. Probably because I used direct control and rolled the nose pretty tight, whic hI never did with the trolls

what size of Pilot Chute was attached to the Fox during your SL jump and what size on your BlackJack . Do you take into consideration the size of the PC when judging flight performance of the canopy ?
I ve never jumped any of these canopies but both have an overall good performance reputation .

If it wasn't the exact same pilot chute I can assure you they were both 46NVZP

For what it's worth, I've had similar results with my old Vtec Fox. Very reliable stand-up landings with good flare down to about 130', and even from 111' in the right conditions (not a headwind). Freefalls from 210' were a breeze, with lots of time to fly and flare.

I'm surprised to hear the Blackjack had troubles. Was that over multiple jumps, or just a single jump?

Michael

But then again if you don´t get satisfactory results from freefalling 205 feet with any modern BASE canopy you´re doing something seriously wrong. :) 205 feet is still from my point of view considered quite "normal" freefalling altitude whereas I would assume that the real benefits from specialized gear only start to show when going for 180feet or below range. (assume because I never FF´d anything that low, my lowest ones for the record are 194feet (59m) with a 265 vented Troll over concrete and with satisfactory results).

My blackjack was great on a 118ft static line. Not a stand up landing, but I think that was due to my bruised heels
Plenty of time to get a flare in, but my deep brakes are really deep so I just left them stowed.

Other wise the BlackJack has been great always stand up on 140ft SL jumps with enough time for a 90 left turn.

Sounds like the fox XS will be a good one for you if you are going to have multiple rigs. I would never take it over 2 seconds of delay time or prepare to be ROCKED. It opens/pressurizes/flies really fast.

The only concern I have is that because it starts flying so quickly it could be problematic in the case of an off heading. My Flik opens and then takes a bit of time before it starts flying forward (we are talking a very small difference). That way I can react a bit slower and not have a strike. However, with more flying speed you can have a more powerful turn. So those are the options you have to weigh.

Personally I don't find jumping stuff that is low fun and would never be able to justify that amount of money on such a limited rig. However, if you have the cash it sounds like a good bet.

^ isn't that just a question of customizing your deep brake setting or am I missing something about the FOX xs???

No. The slower the pressurization, the more of a time lag between bottom skin expansion and full pressurization. The canopy has to be pressurized to become a wing shape (to generate lift and fly forward).

Pressurization speed/cleanness changes the length of this pressurization time lag--customized brake settings change the speed with which the canopy will travel forward _after_ full pressurization has been achieved.

The most marked difference in this regard is in vented v. unvented canopies. Vented canopies are flying almost immediately, giving less time (almost none) to react prior to forward motion.

This is an argument that can be made in favor of using unvented canopies for solid objects. They essentially give you a "pause" button right at the most critical part of the opening, so that you are more likely to respond correctly to the off heading.

There is a counter-argument in favor of vented canopies, and the debate is pretty old (it dates back at least to the inception of vented canopies).

For me personally, the deciding factor for using vents is the post-strike behavior of the canopy. Vented canopies appear far more likely to re-inflate and not drop the jumper all the way to the ground, instead experiencing a series of micro-strikes repeatedly until either reaching the ground or turning around.

Regardless, there is a good technical discussion to be had there, and in my opinion every jumper should familiarize themselves with the pro and con arguments before selecting their own canopy.

further more, the XS has shortened lines and over-sized vents, facilitating even faster pressurization than a standard vented canopy.

Thanks for clarification/education Tom and blitz

I would take a flying canopy over a not flying/stalled canopy any day.

The canopy isn't stalled when it's pressurizing.

Think of the canopy going through the stages of opening:

Line stretch
Bottom Skin Expansion
Cell Pressurization
Flight

The canopy only becomes a wing after cell pressurization. The parachute with bottom skin expansion but that hasn't yet experienced cell pressurization is not yet a wing shape (no airfoil because there is no pressurization).

Since it's not a wing it can't stall ("stall" is what we call it when a wing shape is not generating lift).

In this pre-pressurization state it's basically a big aerodynamic decelerator--like a round parachute. It's not capable of stalling yet because it's not a wing. For the same reason, it's not capable of flying (and moving in whatever direction it's heading) yet.

The time lag between bottom skin expansion and pressurization (the time period when the parachute is not yet a wing, but is slowing your descent rate) can vary a lot between different canopies, and especially between vented (where it is very short) and unvented canopies.

Yes I understand all that. My point is that people seem to believe that the deepest possible brake setting is what is going to save their ass when they end up facing an object. People seem to believe in their deep brakes to the point of disregarding the downsides/consequences of a brake setting that is too deep.
Like I said in my last post. I prefer a parachute that is flying. Not one that is taking its time to pressurize, not one that is set on the verge of a stall, not one that is gonna drop from the sky the second I make any kind of input what so ever. A parachute that isn't flying is next to fucking useless.