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Since I'm nowhere near the experience level to take a BASE FJC or anything of that sort, I find that doing as much research as possible helps me pass the time, and hopefully I'll be well-educated when I get to actually start in the sport.

It seems that a .6 to a .75 wingload is considered the de facto norm in BASE, and I'm somewhat curious about what happens when you're a big guy. I'm 6'3" and about 225lbs, so assuming 15lbs or so for the rig (not even including body armour, etc), I'm looking at a 400 square foot canopy to get a .6 wingload.

Insofar as I've been able to find, the biggest BASE canopies are in the neighbourhood of 330sqft, and that's towards the high end of the recommended wingload, which is probably inadvisable for a newbie jumper.

Surely I'm not the first person to run into this issue, so what's typically done in this sort of situation?

-jump naked
-loose weight
-cut a limb


question to experienced people ... Would a 330 loaded at .75 perform more docile than a 210 at the same wingloading ?? My logic would be yes, as with skyding canopies, the smaller, the twitchier (at same wingloading)...

Question for Grue : what size canopy did you have for your 1st jump ??

Haha, I don't have that much weight to lose, actually. I -might- be able to get down to 220 :P

In any case, my canopy progression:

Jumps 1-5: Skymaster 290 (Static line)
Jumps 6-10: Skymaster 230 (Ripcord)
Jumps 11-44: Raven IV (Throwout from this point on)
Jumps 45-current: Fusion 210

Uhm....

245 / 330 = 0.74 < 0.75

So you'd be okay with a 330. There is actually another canopy-sizing rule besides the 0.6 to 0.75 rule that says; take your naked body weight in pounds and add 100.

Some say this rule more accurately describes the ideal wingloading since heavier people can actually benefit from slightly higher wingloading; e.g. the 0.6 to 0.75 rule is actually non-linear.

Jumping with a canopy this big does bring some considerations that not everybody is aware of though. When the time is right, I would recommend getting in touch with other people jumping canopies in that range and asking their advice.

Also, note that higher wingloaded BASE canopies can be great for some areas (terminal jumps with easier landings) and poor for other areas (low jumps with sketchy small landing areas that require deep approaches). Adjust your jumping to your abilities.

Ok, I guess what I read confused me a little. I thought the .6-.75 rule was for BASE in general, not just newbies. So in other words, I thought ".6 is for newbies, .75 is for very experienced jumpers"

Thanks for your help!

Typically, folks just buy the largest size canopy they can find. Be aware that the size numbers given by manufacturers aren't really that comparable between brands (for example, I once laid a Troll 290 on top of a Blackjack 310 and found them to be almost identical in size). So, don't be fooled into thinking you need to buy the canopy with the largest "size number." Decide which canopy you want (and demo several different canopies when making this decision), then order it in the largest available size.

Jumping skydiving canopies (which are available in larger sizes) isn't really recommended. Some people have tried to use military canopies, tandem canopies, etc, because they were available in such large sizes. Virtually every one of those I've ever seen has had some very strange (and undesirable) slider down openings.

You might also seek some input from other people in the same boat (i.e. folks whose body weight is high enough that they are "overloading" even the largest size canopies by traditional measures). There are a couple on this forum (if you need help finding them, drop me a PM).

Also, be aware that there are going to be jumps that you just aren't going to want to do, as a result of the wingloading and canopy size issues. Tiny people can land in bad areas, especially broken ground, much better than large people. This is just one of those things that you are going to have to accept, and shape your jumping style around.

Ouch. Nope, that's not the way it works.

In fact, in BASE, very experienced jumpers tend to jump lower wingloadings, usually because they've seen enough bad stuff go down that they want the extra safety margin (sometimes also because they are trying to land in more questionable areas, or for other reasons having to do with attempting more advanced jumps).

Ok, that makes good sense. I was avoiding studying when I was reading all this stuff the other night, so it was late at night and I was tired

Are BASE rigs in the same boat as skydiving rigs, in that the container's sized for a small range of sizes? Or does the nature of the way a BASE canopy is packed allow for more container size variation?

Should probably say: "very few experienced jumpers"?

Please self-destruct this post after reading.

The very simple method I've seen for the proper BASE canopy size goes like so:

Weight of your naked body + 100. At 225, you'll want a 330.

aye... my first base gear was .79/1, and my new rig is .55/1.
That little dagger was crazy fast. is crazy fast. still jump it in moab...

Good catch. Thanks. I fixed it.

Yes. It varies depending on the specific container, but many BASE rigs can accept a size up or down.



It usually allows for less variation than a skydiving rig.


Be aware that it's much safer to vary sizes with a velcro rig than a pin rig. In general, it's a good idea to jump a pin rig sized specifically for your canopy. Velcro rigs allow you a bit more wiggle room while still maintaining some safety margin.

I disagree.
I have noticed the opposite to be true. Through the years I have seen many experienced BASE jumpers (including myself) start jumping a lower wing loading (usually a one size bigger canopy). The lower wing loading does give you less penetration but having a larger canopy over your head is a lot more forgiving while doing steep accuracy approaches and dealing with turbulent air.

Higher wing loadings are definitely the trend in the Skydiving environment for swooping and jumping in higher winds.

That's what he meant, he has since edited the post.

Thanks for the clarification Johnny. I'll actually admit that I've always found the term wingloading confusing. I prefer to speak in terms of bigger canopy and smaller canopy since it appeals instantly to intuition; big is slow, small is fast.

Quick, anybody, answer this question in a millisecond without thinking; how do you calculate wingloading, weight over area or area over weight?

Did you cheat?

Obviously at some point the weight to area ratio is a useful metric, but in general discussions I like big and small.

And in life in general I like big; really big. But that's another story...

In skydiving people tend to downsize their canopy to a higher wing-loading as they gain experience, so I understand your thought process completely and you are sort of correct, whereby a more experienced BASE pilot should be able to handle the higher wing loading VS a new BASE jumper. BASE is not like skydiving in this way though, because experienced jumper still want the lower wing loading knowing the reality of the demands a BASE environment puts on the jumper.

I think its more like a ballance thing..
Yes i want a big forgiven canopy over my head,but i like the fact that smaller canopyes crack open faster..

wingloading = load placed on the wing

it becomes challenging as we just throw out numbers and ignore dimensions.

wingloading is simply a pressure, i.e. how much weight must each square foot support.

correctly stated, it's 0.75 lbs/sq ft.
(giving dimensions also permits people to convert to kg/sq meter.)

hope that helps!

I totally agree with you Faber, it is about finding a good balance.
A canopy that is too big can have negatives traits about it. Bigger canopies pressurize slower on opening like you said (even to the extent of end cell closure problems), and they turn slower, and have less penetration.
So you want to try and get the best of both worlds.

I think i fall into the category of the larger jumper. I currently weigh 225lbs without gear. I jump the following configurations

ace280 for slider up jumps with larger landing areas which allow faster (skydiving type) toggles up, let it fly then flare approaches.

ace310 which i use for the whole range of jumps but not for jumps where i expect less than 5 seconds of canopy time, as i do experience more end cell closure and wierd pressurisation and jelly fishing.

troll305 which so far has been going great and i'd be happier to jump the lower stuff where i think canopy time is going to be under 5 seconds. The vents and valves mean it bangs open and pressurises solidly a lot more quickly than the ace.

As a bigger guy under a bigger canopy i currently avoid freefalls under 210ft. I just seem to get a lot less canopy time than my jump buddies, although there are too many variables involved to say with any certainty that it is down to the canopy size alone.

It is important to know your own limits. Not just ability but psychological limits and maybe even physiological limits. Just because you're a bigger guy doesn't mean you have stronger bones. Extra body mass puts more stress on your bones in an impact situation which lighter jumpers may just walk away from. Just because all these weedy little freaks can land in an area and be okay doesn't mean it will be okay for you.

Buy a good pair of boots (hanwags or the like). Your ankles will be pushed to their limits when 220+ pounds of man and rig comes banging down on them at 15mph. Your tib and fibs are seriously at risk. I've broken both mine left and right.

Seriously think about perfecting a good plf. It's better to be laughed at for plf'ing than to be laughed at for being on crutches.

Be prepared to have the piss taken out of you constantly, and don't be surprised if you land yourself a less than flattering nickname.

My one personal recommendation to a larger BASE jumper would be to try and build up a lot more upper body strength (which i lack in spades). It could prove very useful for climbing over fences, builders hoardings, suicide nets and barriers,hoists, trees, ladders, ropes and cliffs. You'll be wearing big sturdy boots which make it really difficult to climb in so you need to rely on your upper body strength (or the shoulders of a friend) and it means you'll be able to punch them harder when they start taking the piss out of you.

Your weight isn't necessarily helping you, but it certainly shouldn't stop you when the time comes for you to decide whether you want to get into BASE or not.


ian

Sort of, but I bet it took you longer than a millisecond to type that answer. I'm well familiar with wingloading and what they mean. I was trying to convey that wingloading always takes a fraction of a second longer to understand than big and small does.

dude, I'm a blonde. my brain doesn't work at millisecond speed at ANYTHING.

"big" and "small" might be useful shorthand, but make comparisons difficult. how can you use these adjectives and provide guidance?

if you want to be totally geeky, realize your wingloading is the same as the average pressure differential between the upper and lower skins.

a canopy loaded at 2.25 must generate 3 times as much aerodynamic forces as one loaded at 0.75.

and actually, I was surprised by your original question. I didn't think my reply would contain anything new to you.

I'll chime in as I'm 220 without gear.

I also jump a Troll (MDV DW)305 now -I love it. I have a Mojo 280 that I've used on mostly slider-up jumps with clear, open landing areas -also frequently landing into a moderate headwind. I wouldn't want to land it on pavement or rocks.

I can easily see getting a 320+ in the future for more technical jumps and tight or knarly landing areas. Bigger is definitely better canopy-wise, but not in terms of pounds. I really like and emphasize the previous advice: 1) think hard about the types of jumps you plan (or DON'T plan) to do. 2) Use good boots 3) PLF's are OK

good post mate

I totally agree. I was mostly referring to Tom's original post where there was initial syntactial confusion about whether experienced BASE jumpers fly canopies with a lower or higher wingloading. I find it much more intuitive if I read: "experienced BASE jumpers will tend to choose larger canopies."

Two cents...

I'm certainly not a big guy at 6'0" and 168lbs and I'm only an average rock climber, but the mechanics of climbing work pretty much the same for most people, so your advice of focusing on adding upper body strength to facilitate easier climbing confuses me, as it goes against conventional rock climbing wisdom, which is to focus on using your leg strength for climbing, especially on the relatively easy climbs needed to access most basejumps, improving your climbing technique and footwork will be of much greater benefit to you than some increased upper body strength.

I also find my boots (hanwags) to climb much better than most casual footwear, i.e. sneakers and even most hiking boots, due to the good edging ability and decent rubber soles.

sounds like some time in the climbing gym will make your base life much easier

Hi Sam

My own personal experience is the absolute opposite. Leg strength (which i have) is of very little use to you when you're trying to clamber over a smooth builders hoarding around a site. You end up hanging off the top, scrambling away with your legs trying to get a toe hold on anything (a screw head or splinter of wood) to push up off . If you had upper body strength then you'd jump, catch the top of the wood and pull yourself up without all the kicking and thrashing and noisiness.

The most common barrier for BASE jumpers i would say is your standard link fence with barbed wire across the top. They also tend to overhang to hamper climbing them. My experience is that climbing anything which overhangs requires upper body strength, arm strength, chest strength (again which i lack in proportion to my body weight). That famous shot of Cruise hanging in MI2. I don't see strong legs helping him out at that particular moment.

Now your experience may be different to mine but then your not as heavy as me, and they don't call you 'hippo'.

What i can tell you with 100% certainty is that if i could be arsed to work out and build myself into a better BASE jumper, the thing i'd be working on would be my upper body.

But then don't just ask me, ask the poor bastards I jump with.

ian

ps. and hanwags couldn't be further removed from the rock climbing specific shoes that are used in that sport (canyons etc)

Depends what you're climbing.

Anyway, I'd like to go back to Faber's comment:


Does anyone have any views on how true this is? I'm curious to know how much altitude is lost (or time taken to deploy; although I think this may give a slightly different answer) for a given canopy type over a range of sizes and wing loadings: has anyone ever compared this?

Ian is right, he is fat and weak. Sam, try using more than one sentence per paragraph.

Dude, whereas you have moved to that bastion of civilization and highly evolved grammar, i have moved to the continent of bigger is better and as I start doing as the romans do i am permanently so caffeinated and sugared up that slowing down for anything is not really an option especially silly things like punctuation!!! that's why I climb 600 ft in the time it takes you to do 400 ft so give Ian a break at least he's NOT fat weak AND a saffer like you!

Now, as much as a size or so bigger would be nice I currently jumpa Troll MDV 305. I am hovering around 240 lbs in the buff! (down Jaap, I am still straight!)

I do wear armour and have a had a couple of hard-ish landings but generally I am very happy with the way it performs for me even at moderate elevations ASL like 4000ft. +

If it requires really sinking it in I am in PLF mode before I exit.

Feel free to contact me with any questions although keep in mind I only have 43 jumps and mostly terminal.
sabredave@yahoo.com

Later

Not just slider down. I finally got to see the BD '05 video and my MT-1 just looks all funky and scary as it's inflating. It's in the first jump section at 39 minutes. I'm the B.U.F.F. with the redshirt and chrome helmet. Watch the opening, it's just ugly, ugly.

Definitely broke me of any lingering desire to do anymore BASE with the MT-1.

-Blind

Several years ago, I tested this out with several Mojo's of different sizes. All my factual data is from those jumps, all on Mojo canopies. While you can decide what to extrapolate from there, be aware that I'm not saying anything about any other parachutes.

My experience was that the difference between the smalles size we tested (Mojo 220) and the largest (Mojo 280) was between 35 and 50 feet (depending on the jump, as there was variability). These are all for slider down go and throw freefall deployments.

I am of the opinion that the canopy model is far more important than the canopy size in these kinds of variabilities (so that I'd rather jump a Blackjack 310 than an unvented FOX 225, if it was critical).

Got a clip of that?

I weight 260, 6'5" and had a fine time with my ace 310. In deep brakes there was air flow out the front of the canopy, which is not good, but wasn't bad enough to worry about.

the big guy story made me cry. i think i am going to quit jumping due to all the "limitations" the "big" guys face.

Yo baldy. Wind yer neck in.

ian

So far, I am the biggest jumper to post on this subject. I currently jump a vented FLiK 322. It does well for me - better than my Mojo 280 did. I found the Mojo 280 was loaded up so high that it was very sensitive to body position on opening. Anything less than a perfect body position and I was off heading. This is not the case with my FLiK 322.

If you are jumping lower objects - get a vented canopy. I found it makes a huge difference on low objects, as the canopy will pressurize faster and thus get flying faster. This will give you a better flare. I originally bought the FLik unvented and it didn't do so well on low jumps (sub-300). I cracked my tailbone on a low jump because the canopy didn't have enough time to get flying before it was time to flare. (Click here for a vented vs. nonvented video comparison.) I feel that the FLiK lands me well given my size. I land hard sometimes and that is par for the course, so I am prepared for it (i.e. PLF). However, I wouldn't jump it in a place that would require me to fly in deep brakes for landing as the flare would be on-existent and I would just pound in. I prefer to fly it in as little brakes as I can so that I can get some flare out of it.

I have jumped a larger canopy and it landed wonderful - even with just rear risers. But, there's a reason tandem masters like their passengers to help them steer and flare. On a canopy that big, I didn't have the strength to fly it in deep brakes very long and toggle pressure was very high. But, it did land me great. This is something the canopy designers will have to work on.

Also know that, generally, the bigger the canopy, the longer it takes to get open and flying (i.e. pressurized and creating lift). And your PC sizes will most likely be a size bigger than you smaller buddy’s. What this means to you is that when your 160 lb buddy freefalls a 210' object jumping his 220’ canopy, you probably should not. I won't even consider freefalling below 250' just because it takes longer for my canopy to get open with full pressurization. As for the PC, when your buddy is using is 38" off an object - you might need a 42" because you have all that extra fabric and weight to get off your back. The gear manufacturers can tell you exactly what size PC you need for you canopy at a given delay - so don't quote me.

You're doing the right thing - asking other big jumpers about their experiences and opinions. Check with the various gear manufacturers too. They make the big gear and know the details about jumping it and how it differs from the smaller gear.

and you are how big? or..what is your WL on the 322?

I think your absolutely right on that one. I only have an exit weight of 235 lbs so the larger 300+ square foot canopies are ok for me, but I think it's high time someone designs a BASE canopy for the bigger jumpers. Not just scale a 240sq ft up to 300 sq ft or more.

was it at the same wingloading ?? the difference is huge indeed.

Yeah, I am interested in that info. Right now I'm tryign to decide between the Flik 322 and 350. A 350 would give me around a .9 WL while the 322 would be a hair about 1 to 1.

-Blind

Wing loading was the same for both jumps although they were done some time apart. I didn't lose/gain any weight and wore the same gear in each jump. The first jump (unvented) is when I busted my tailbone. Thank goodness for those inflatable doughnuts!

I will not post my weight or wingloading in the public forum - don't care to get flamed. If you want to discuss it via PM, then I'd be happy to. For the few that know me, they know my statement is truthful.