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Hi guys!
I'm pretty new here but have few questions.

I will start BASE jumping this spring and as I'm traveling to US before I want to bring back a BASE gear from there.

For now I'm thinking of ordering a Gargoyle (with dynamic corners) and a Troll MDV 265 (I weight about 200lbs with skydiving gear).

I've been reading a lot, got advice from local BASE jumpers and considering Tom's advice I'm wondering if my choice is good.
I live now where it could be possible to jump A's and B's, but I'm from the French Alps (parents still live there, and grand-parents have a spot over their garden ) and will start over there (B first).
I'm not keen on low height jumps, but I know that sometimes you have objects you want to jump that are rather low.

Thanks for your advice.

Julien.

Rig selection is fine, everyone has different opinions. But to start off on a B seems a little misguided. Maybe you were implying B as Bridge and NOT Building.

See:
http://www.blincmagazine.com/cms/article_307.shtml

Edit to add:
I don't know how to make it clicky

Now it's a clicky

I had JFK on MSN a couple of days ago, I think he indeed means S, and not B

Julz, B is Building, not Bridge

Yep sorry guys, I shortened my message too quickly.
I meant S of course.
Thanks for your advices I will check the link.

Jul.

The same article is linked right at the top of the page. My First BASE Rig

Yep I've read this one and I was wondering about the MDV on the Troll but seems that Troll without MDV and Troll with MDV have different behaviour. After reading a bit more seems Troll+MDV is a good combination.

What do you think?

Jul.

I like the Troll with MDV. Also the Troll is quite popular in Europe generally, so you ought to be able to find folks who have them if you need help/advice with the canopy as you progress.

Since I wrote that article, it's become increasingly difficult to find Visions. The closest thing, in my opinion, is Ray Losli's Soft Cock (cue skinflicka with witty comment). Unfortunately you can't get them over there.

The Gargoyle is an excellent rig, especially if you are planning on trips to Norway (or the Alps) for big walls.

Troll MDV in Gargoyle sounds like a good choice for your application.

Yep this canopy has been advised to me many times already.


Thanks, I think that confirm my idea and I will order soon ;-)

Jul.

Hey Tom, In that article you advise against vents n' valves...


Do you honestly believe that vents are not safe for beginners

Interesting... Maybe Ray will make me a dealer.

RAY!

Some separate thoughts:

1) I wrote that article some time ago. At that time, in my opinion, there was not sufficient field evidence to declare bottom skin inlets "proven in the field" and I think beginners should stick to rock solid, tried and true, simple gear. Were I writing it today (there's a rewrite somewhere on my hard drive, amongst my seemingly endless "to do" list), I would probably recommend secondary inlets for some jumpers.


2) Whether or not secondary inlets are worth the money depends greatly on your particular jumping conditions.

Dwain once said to me "well, what are you going to do when your beginner has a 180 off an underhung cliff?" My gut response was "what the heck are you doing putting a beginner off an underhung cliff?"

But, in truth, there are parts of the world where low and/or underhung objects are jumped by beginners. Usually this is (as in Australia, which I think you are in) because there isn't a terribly good selection of objects.

So that whole exchange between Dwain and I was based on the fact that he was used to seeing beginners jumping those objects (in Oz) and I was used to seeing people rack up many (sometimes several hundred) jumps off much safer objects (in Northern California) before moving to such sites.

I believe it is silly to recommend that everyone get canopies with bottom skin inlets. I know many jumpers who paid the extra 400 bucks for valves, and jump terminal walls, or only wind-through towers (or some other set of sites where the valves aren't really very important). In fact, I'd guess the majority of folks with secondary inlets fall into this category.


3) Canopies with overly deep brakes and vents _do_ experience back surge on opening. I've had it happen, when testing some things. I've also seen a jumper hung on an object due to backsurge (which, despite an on-heading opening, pushed him back into an underhung tower--precisely the kind of situation where you'd think vents would be recommended).

At least one major manufacturer (the one that pushed secondary inlets for all jumpers) told people to never, under any circumstances customize their DBS (my thoughts on this are a whole separate thread, but suffice to say I think it borders on criminal negligence). Combine these two and you create a situation where someone could easily find themselves with overly deep brakes, which they have not customized (per manufacturers recommendation), and with secondary inlets (creating backsurge, when combined with the overly deep brakes) pushed by the canopy manufacturer.

Given this, I think it unwise to universally endorse the addition of secondary inlets on a canopy without further evaluating the situation.


So, there you go, my rant for the evening...

So other than cost, vents and valves don't make much of a difference one way or another where the chances of an object strike are low. However they would add flexibility for more technical jumps in the future.



I agree completely.



Yep, therefore they would have to be on the conservative side, as they wouldn't want people opening in a stall. (I agree though, that everyone should customise their DBS)



So in other words, the higher the wing loading, the more inappropriate the standard DBS with respect to backsurge, or is it the lower the wing loading?

But back to the topic, with a customised DBS would you then recommend secondary inlets?


Thanks Tom, actually very informative.

Definitely true. But recognize that there are areas of the world where jumpers never progress to what you might consider more technical jumps. I know jumpers with hundreds of jumps who've never had to worry about that.

And if that's the case, you probably ought to buy a second canopy for the nasty stuff, after (a) canopies advance for another year or three, (b) you know better what you like, and have seen more canopies in action, and (c) you've worn out that first canopy anyway.


Lower wingloading. Lower wingloading will make the same (absolute) brake setting point "deeper" relative to the jumper. So more weight = deeper (further toward the cascade) brakes.

One of the things that concerned me at the time was that I'd see new jumpers hearing Dwain say "get a canopy with vtec" and also "lighter wingloading will save you in bad situation" (both of which were solid advice), but they'd also hear BR saying "don't touch our brake setting." But Dwain was talking about wingloadings pushing .6, and BR was setting their brakes for their recommended wingloading of .75. End result? They'd follow all the expert advice and manufacturer recommendations, and end up with a low wingloading, vents, and brakes they didn't customize (which were set for someone substantially heavier than they). That's a classic backsurge scenario--and I saw it happen (several times over my own head).

So back to your original question...

As of last night I am the lucky owner of a shiny new Gargoyle and Troll 265 MDV. I spent most of the night going over every line, cascade, crossport, valve and everything else you could think of and all I can say is that it is top class workmanship all the way.

Will hopefully be jumping it tomorrow and will be able to add more comments then.
(shit-eating grin)

G

Thanks Tom, this is a very interesting thread.

I need to make something clear : isn't the backsurge on opening the beginning of a stall ? If it is, what has this to do with vents ?
I thought that stall on opening could occur if wingloading was too low and brakes too deep, but i also thought that precisely, one of the purpose of vents was to make the stall point "further"...

I'm interested in getting a vented canopy, my wingloading is a bit low, and I never customize my gear... So this thread is of a great interest for me !

No. The reason I say this is that I have taken exactly the same canopy and sewn vents (no valves--this was before valves were released) into it. Using the same deep brake setting as before (which was properly set), the canopy began experiencing back surge. When I reported this phenomenon to the manufacturer, their response was "don't worry, we're taking the deeper setting out of all future canopies, and telling people not to change them, so it shouldn't be a big issue for most people."

I believe the backsurge occurs because the air forced up into the canopy through the nose is then pushed out the nose, forcing the canopy backward in a classic "action-reaction" way. This backward motion momentarily stalls the wing. However, if you experience back surge, but do not touch the control inputs (I did this too, off a bridge, to examine this phenomenon), the canopy then begins to fly (slowly, as it is in deep brakes) and is not stalled.

In fairness, I do not know that anyone has really analyzed this phenomenon in depth. The closest I've seen to an attempt was done by Consolidated Rigging, during the development of the Blackjack canopy, when they attached streamers to various points to track air flow, and the canopy was deployed numerous times in various brake configurations (some of them too deep).

Another thought that just hit me.

Every manufacturer is willing to retrofit their canopies with secondary inlets of some kind. It would be just as easy to have them added later, when you know you want the, (and know you want to spend the money).

Could be interesting but for us in Europe it means spending money in shipping too... so might be worth the investment at the beginning... don't you think so?

Could be. Although if you are buying a Troll, wouldn't you just have to send it to Stane in Slovenia? So that would actually be the least shipping for retrofit of your canopy options.

Still, I think that the Troll in particular has poor enough openings unvented that it's worth buying the MDV option up front. It's also got very well designed valves, which, in my opinion, are superior to the other options on the market (I feel strongly enough about this that I once had another manufacturers canopy retrofitted with MDV style valves by a third party).

True.. still lot of things to learn, like manufacturer addresses ;-)


Yep, now I'm sure of my choice, Gargoyle+troll 265 MDV
Order this weekend ;-)

Thanks.

Jul.

AIRLOCKS with bottom skin vents!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Seriously, if there is a manufacturer out there that is willing to make one, (again?) I'll buy one...
There seems to be another potential advantage!

I am a new at BASE also. I went for the Gargoyle/ Troll MDV 265. Absolutely love it . Workmanship , quality , design and performance are excellent.

I've long wanted one of those. As an added bonus, the canopy ought to stay pressurized in full stall, which would make double riser stalls (to avoid imminent object strike) much nicer, and less costly of altitude.

I know that Vertigo was once talking about prototyping an airlocked BASE canopy (I believe it was called the Shaman). I'm not sure where that project ended up, other than the obvious (it never made it to public release). But perhaps now that they've got the valved Rock Dragon, Apex might consider revisiting the topic (hint, hint--I know you read these forums Jimmy).

As long as I'm dreaming, why not add airlocks on the tail as well, so that the canopy could take in air from that end during a double riser maneuver, and essentially "fly" (yes, I know the airfoil doesn't work that way) backward?

Seriously- I'll put the offer there, again. I will work overtime at my crappy job to afford another canopy, if someone will build me an airlocked canopy with bottom skin vents. And I'll go to TF and knock 6 jumps a day until I have about 100 videos with belly mount DV shooting up to get video of the openings. I'll jump it from a plane with friends taping from the side, in all flight profiles. I've tried and tried to get interest going on this, I can't imagine that can be all bad... If it is a horrible idea, tell me why. If it just hasn't been tested as far as it could, build it...

Me too!

Hmmm. Maybe I'll start making some phone calls. But I bet I could just buy a stock canopy and have someone sew in valves in various places.

Yea, once upon a time, I had a shiny new vented/valved canopy. Everything about it kicks ass. This last year of heavy jumping has taken a toll on it, it isn't new anymore. And I have two new ones that were born to replace it.

Anyone know enough about airlock technology, and how to use a sewing machine, to give it a shot? Even if this idea doesn't work, I can take the airlocks out. I am willing to spend my own money to try this, if someone has the skills and knowledge to go in the right direction...?

I bet you could send off a new canopy to Brian Germain and have it retro'd with airlocks.

wonder what that would cost?

I have heard that Brian built one as a prototype, that was jumped by Clint here in Colorado many years ago. I believe it exploded on opening during a terminal jump from an airplane during testing.

This is starting to slip and slide from the original topic so feel free Tom to split this to another thread if you want to. I think we've discussed the openings of the unvented Troll before in some other thread but could you please elaborate your view a bit further ? How are they poor ? Do they open off heading or is pressurization poor or what is wrong with the openings from your point of view ? I jump a unvented Troll and have 40 jumps on it so far and I'm very happy with the openings. I've taken my unvented troll from full terminals to low short delays and I'm very happy with it. Of course since I'm a newbie to this sport and don't have much experience with other canopies, it just could be that I don't know of anything better.

My experience with my unvented Troll was that the openings were significantly slower and less consistent than with (for example) a Mojo.

(As an aside, this was one of the reasons I found the "Troll is just a copy of the Mojo" to be bunk--much as the later "Ace is just a copy of a Troll" urban myth is also totally wrong. The three canopies have easily noticeable differences in openings and flight, and I tend to think that anyone who believes they are knockoffs of each other--in whatever order--simply hasn't jumped all three canopies.)

When jumping my Troll initially (before the MDV was added) I made about 50 jumps on it and noticed that pressurization was very inconsistent. The canopy would experience (asymmetric) pressure waves during secondary inflation (after bottoms skin expansion) that would roll in different directions on different openings. I couldn't explain why this was happening, aside from the observations that the slider down openings seemed to take noticeably longer than the other canopies I had experienced. I speculated that the slow secondary (cell) inflation allowed more time for the random factors to come into play.

I think it's very important to note that I'm discussing my particular unvented Troll. This was a relatively early Troll in the US, although I do know that I know another jumper who demoed one prior to this and felt the low airspeed openings were so poor that he nicknamed it "the jellyfish." I believe this was prior to a crossport enlargement which improved pressurization.

Another thing to consider: I've often found folks with experience on only one canopy (or perhaps a handful of jumps on other canopies) touting their canopy as "opening best", or "having hard openings", or some other qualitative assessment of performance, with no basis for comparison. I've especially noticed this with a number of European jumpers reporting "hard" openings on Trolls. After some side by side comparisons, it turned out that the openings they thought were "hard" or "clean" were in fact much softer than openings on other canopies. At any rate, I always increase greatly the size of the salt grain I take when hearing reports on canopy performance form jumpers who have less than 100 jumps on at least two other canopies as a basis for comparison (this is one of the reasons I treasured DW's canopy opinions so much--he had more than 100 jumps on at least 5 different BASE canopies).

Sorry to lecture. I hope I'm not coming across as condescending or offensive. I've just run out of time to re-edit this, so I may come back later and try to soften the tone.

I've edited a significant portion of this thread to remove discussion of specific jumping in a specific location. I did this after discussion with locals in that area, and without effecting the original thrust of the thread.

I started that discussion in an aside, so I'm officially slapping myself on the wrist now.

Don't be sorry, I asked your opinion and got it. As I said in my post, I'm far from being expert in basecanopies and definately far from being able to give a good review since I do have very limited excperience with other canopies (than my uvented troll). I asked for your opinion conserning the troll because I wanted know what kind of behavior I should look and see wheter it exists in my troll and propably what things i should consider and pay special attention when looking other peoples jumping.