THE INEFFICIENT BACKPACK

[Chris C]

All this discussion for “280 cu in” i.e. 4.6L???

Was there a typo like this backpack prototype is 2800 cu in (45.9L)?

For a capacity less than 5L, it seems to me that almost any backpack configuration with a sternum strap would be workable.

[S. Steele]

Chris C: Did you have an opportunity to review the post regarding the V02 treadmill tests?

[Paul S.]

I think you need to get your money back on those tests.

[Chris C]

S. Steele: I’ve had back problems since my teens and am conscious about ergonomics. I saw and reread that VO2 post. I’m not sure why that tester could not go 10 minutes during the third trial period.

In evaluating weight and volume, refer to my personal experience of living in NYC without a car. All groceries, etc., are carried home by myself. The subway is 10-15 minutes away and my walk home is all uphill. Cabs are too costly.

When my son was 15 to 25 lbs, I would front-carry him in an Ergobaby carrier and with my daypack carrying even more stuff. I even carried my son while standing–and dancing–through an entire David Byrne concert in Brooklyn. Now that he’s older, he goes camping with Osprey Ace 50 since the torso size is adjustable.

While working at a camping store, it was invaluable to try on backpacks with weights or actual tents and sleeping bags.

That VO2 study would be more compelling if done with 30L (avg size of my daypacks) or 55L (camping) or 80L (winter camping).

I’m happy to test out your design around NYC. However, since the capacity is significantly less than what I’m used to, I’m not sure I will be able to feel the difference.

[S. Steele]

Paul S: The tests told me that the fellow who performed the tests was incapable of finishing the last test. If you or any others think that what was performed was a ruse then I’ll be happy to provide the report prepared by the doctor which includes heart rate data graphs for each test.

Chris C: The pack is comfortable as it provides about a third of the weight in front. When the water is depleted the pack is essentially balanced front and rear. It’s advantage is for a comfortable day and overnight pack as well as for day trips from a base camp.

[Woubeir (from Europe)]

Well, I want the test report. In the first place just to know already how exactly the test was performed. Without that, it is hard to say if the results are actually meaningfull or not.

[Roger Caffin]

The Science community is moving hard to full disclosure of all data these days.

Cheers

[S. Steele]

Woubeir and Roger: Here’s the V02 test results:

[Greg Mihalik]

 

 

[Roger Caffin]

Interesting, but not all that scientific.

Only one test subject as far as I can see – so applicability to the general public is entirely unknown. The physical fitness of the test subject is unknown as well.

The heading mentions ‘stages’ but does not explain what they are. It says the Regular pack only completed 8 stages, but the table says instead ‘Time 8 minutes’. This suggests that only a single run was done in each test. Variability in results is therefore completely unknown. It may be significant.

The test time is of the order of 10 minutes. This is meaningless for a walker who might be going for 8 HOURS. Quite a few walkers are barely warmed up after 10 minutes. The relevance of the test is therefore minimal for us.

The test uses VO2 max, but this is only a measure of how much oxygen was used. It does not measure the efficiency with which the inhaled oxygen is used – it can’t. I note that at 4 kph the test run with the regular pack has the lowest VO2 max: does this mean the regular pack required the least effort?

There is no heart rate data provided. Without this very basic information we cannot deduce anything about the tests.

The order of the tests is not specified. So we don’t know which tests were done while the single test subject was fresh, and which test was done at the end when he (or she) was most tired.

The difference seems to be a few percent after 10 minutes. Since we don’t know what order the tests were done in, nor what sort of variability was found in test runs, this difference is meaningless.

I could go on, but I won’t. Instead I will rant for a moment. These sorts of psuedo-scientific tests are the typical output for people who have bought some shiny new equipment but who have not been trained in research and experimental design. They haven’t a clue what they are doing. These results are little more than anecdotal, and would not be accepted in any respected refereed journal. They might prompt an interest in a properly planned experiment, but that is all.

Sorry – but we see far too much of this psuedo crap stuff these days.

Cheers

[Woubeir (from Europe)]

Well, I want the FULL report, not just the results.

And +1 to Roger

[Roger Caffin]

That might be all there is?

Cheers

[Woubeir (from Europe)]

If that’s all there is, the test is worthless to me. No info about testprocedures and -conditions, no analysis of the data, …

[BCap]

If a single test like that cost a non-trivial amount of cash then I would recommend not doing them. I cannot see any possible conclusion you could draw from the test results given.  While your pack design may be more efficient, and that efficiency might make a meaningful difference when integrated over the course of a full day, it is likely that the difference would be small enough that a treadmill study would have a very difficult time picking it out.  The most important variable is clearly going to be how much weight is in a pack and does the pack have straps — everything after that becomes a small effect.  You’d need a few dozen of such tests to establish your controls/baselines in any remotely meaningful way and even then I am betting the results would be worthless from a scientific perspective (might be useful for marketing however).

You’d be better off getting your pack on forum members and trying to convert them into believers and report back.  I think that would be the closest thing to a meaningful test that you could do.  And if you really do want to market this, at the end of the day it will likely be the perceived effort that is more relevant than the actual effort — also note that this is linked to your brand likability, which you have not done a very good job promoting on this forum.  After all, most backpacking gear seems to be sold based on fads, not facts.  For example (not to pick on them, there are many other examples) look at Palante packs.  What do they do that’s meaningfully different from any of the other cottage gear makes?  But for some reasons reddit seems to have a torrid love affair with them.

[Nick Gatel]

You’d be better off getting your pack on forum members and trying to convert them into believers and report back. I think that would be the closest thing to a meaningful test that you could do. And if you really do want to market this, at the end of the day it will likely be the perceived effort that is more relevant than the actual effort — also note that this is linked to your brand likability, which you have not done a very good job promoting on this forum. After all, most backpacking gear seems to be sold based on fads, not facts.

+1

[Bob Moulder]

But for some reasons reddit seems to have a torrid love affair with them.

‘Cause the Z-man does epic hikes with ’em!     ;^)

And that’s not criticism; he’s a likable guy, intimately involved in the design process and actually uses them a LOT, and does mega promotion thru social media. He’s quite literally walking the walk.

[bjc]

I will add one more piece to Roger’s critique of the vo2max test. Research has shown that vo2max is not a reliable predictor of performance.  We used to think it did, but all it really does is tell us what range of performers you probably belong in. Lactate threshold is a better predictor, although as Roger has pointed out there are a number of significant variables that effect performance. Adding or subtracting weight in a vo2 max test has always changed its value. But does a lower vo2max value by itself mean lower performance? The answer is no.

[S. Steele]

Roger: Per each of your comments, I’ve provided the following:

Sorry about that but the one test subject was all I could afford and was meant to determine some kind of result. I agree that more tests need to be performed. Perhaps you’ll pay for them.

The stages are one minute intervals in which the treadmill was incrimented 7% higher.

The test is a standard recommended V02 stress test to determine patient limits.

He couldn’t get his heart rate higher because the pack prevented him from attaining a higher rate.

You failed to notice HR = heart rate.

Each test was performed once a week.

Same as previous comment.

I had previously commented that I had hoped to have a University Performance Lab do the testing such as NOLS, Pennsylvania, USA, however no bite. Perhaps you could offer a solution and pay for it as well.

Cheers

[S. Steele]

I just don’t understand it. All i’ve done is present THE  iNEFFICIENT BACKPACK, for review and it results in a I don;t believe it with a lot of childish responses included. I then hoped to clarify it by presenting the fact that it was supported by the fact that a hiker and runner performed testing and received disbelief with additional nonsense. I’m surprised at the community thinking that I’m some phony. I submitted actual bio-mechanical results regarding the backpack as well the testing of same. I’m principally disappointed that the community thinks ill of me. My intent was honorable and sincere. This is my last comment

[Roger Caffin]

Hi Steele

Well, I guess your article or idea has been reviewed. It sems to have received some negative reviews. That happens. Accept or reject the feedback as you see fit.

I suggest that the testing you chose to pay for is not suited to the product. 10 minutes might be relevant to Central Park, but it is irrelevant to backpackers.

Several have suggested putting the packs out in the field to get feedback from other walkers. That works, and is probably the only thing which will convince customers. Aarn’s packs work well for Aarn, but are pretty awful for many others. That is a trap for any product: it can be too tuned to one person.

Looking at the Heart Rates, I can see no statistical difference across the lot – but that makes sense for a 10 minute test. Try a 4 hour test instead, with 10 walkers and on 10 different walks, all going at the same speed with the same pack weights and shoes. Then repeat allowing them to travel at their own speeds. Then repeat under different weather conditions. For this you could use the simplest Heart Rate Monitors.

Cheers

[Luke F]

I just don’t understand it….

I mean this in the nicest way possible, but that about sums up the problem. Perhaps take a break and re-read this whole thread in a few weeks and see if any of it makes more sense, or have a third party read the thread and give you feedback. Public perception is often more important then the merits of the design itself, consider this an early test of public perception for your product, figure out why this thread went sideways and then learn from it.  Most products make concessions (sometimes massive ones) in order to be appealing to the public, the less interested you are in selling products the fewer concessions you have to make.

You could also try presenting your product to other online communities and test the perception there, I could recommend a few sub reddits that have varying levels of skepticism, you have pretty much started at the top as far as scientific rigor, maybe you could work your way down until you find your target audience.

In the end you probably have to decide whether it is more important to you to be right or to sell your invention.

[jimmy b]

Mr Streele

If you are so convinced in this products viability put YOUR money where your mouth and/or test results are. Kinda like sh*t or get off the pot in layman’s terms. Invest in a first run of you packs, get your self a web sight or hit the road and get them in the retail stores. Then you will actually prove its worth in the real world. Hard as you try I doubt your going to sell this crowd. That says nothing about us other than in general this group is a pretty savvy bunch who are not quick to bite unless the product is a proven commodity.

IMO you have sold yourself on your product and are blind to objective feedback. After all there is no reason for anyone here to unfairly give it a poor critique. I don’t see anyone here with a competing product or any other dog in this fight. My sense now is this was some kind of intellectual exercise more than an actual plan to develop a marketable product.

[Roger Caffin]

Another option could be to make up 10 packs and to ask BPL to find field testers for them. After a period of testing, the testers’ comments could be published here. This is possible.

However, you would have to accept that the responses from the field testers would NOT be subject to any editing by yourself beforehand. They would be strictly as each tester writes. It’s a gamble.

Cheers
Roger Caffin
Online Community Monitor
Backpacking Light

[Jeffs Eleven]

I just dont see how anything <5L is even relevent here. Try an ultra running site?

Nobody here wants you to fail.

[JCH]

According to his last post, the OP has left the building so none of our subsequent comments, no matter how logical or well intentioned, are likely to make any difference.

This thread reminds me of a co-worker I had several years back.  When faced with a problem this person would routinely ask for my opinion as to the source of the problem, or it’s solution…having already decided in their mind what the answer was.  If my investigation did not quickly mirror this person’s predetermined answer, they would start arguing their point, often without waiting for my complete answer. It soon became clear that they did not want an honest analysis of the situation, nor an exploration of the possibilities, but rather were only interested in validation of their pre-determined ideas.

Our personal opinions are, by definition, correct…otherwise they would not be the opinions we have chosen to hold.  That said we must be willing to entertain the notion that our opinions are not correct, no matter how much thought or energy has been thus far invested in selecting them.  With rare exception, I find the BPL community to be open to new ideas, especially when presented logically, fairly and with data to back them up.  And when not, as evidenced, this same community can be a royal bitch.

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