Click to view our Accessibility Statement or contact us with accessibility-related questions
Showing 1 of 675 conversations about:
arthast
2
Feb 1, 2019
bookmark_border
Hi Dan, If using fixed length 48" CF poles, will tilting the pole to lower the overall height to ~46" make them more susceptible to damage due to the forces being applied at an angle instead of down the length of the tube? Would appreciate your thoughts. Thanks!
Feb 1, 2019
dandurston
5116
Dan Durston
Feb 1, 2019
bookmark_border
arthastThe physics of this get pretty complicated and counter intuitive, but basically even with an angled pole the force is still applied down the length of the tube. I know that sounds crazy, but take a pencil and hold it between two of your fingers tips. No matter how you move your hands around, you can only apply a force down the length of that pencil and not at an angle to it. To apply force to the side of it, you actually have to grasp the side of the pencil rather than just push on the ends. What happens to a tent when the pole is on angle is that the force on the tent from that pole is not straight up like it would ideally be, but rather off to one side. So the pitch suffers, not the pole. If you imagine a simple 1 pole pyramid shelter with the pole angled severely, that shelter will be very robust to the wind from one direction but very vulnerable from the other. The pole isn't going to fail but the shelter might. So if it is stormy then you should mostly be concerned with the well being of the shelter. With your angled pole, you would ideally angle it so the pole is tilted towards the end wall (pink line below), rather than away from it (green line), so it becomes more wind resistant on that exposed side rather than less.
search
Since you would have two poles doing this - one on each end - it might actually be stronger in a storm that with your poles straight up and down. Note that some tents actually do this as an intentional part of the design like the Nemo Veda 1P:
search
Really though, the peaks are typically 46.5" so it doesn't take much of an angle to fit a 48" pole in there. You're only going to have the base off to the side by 4-6", so it's not really going to matter much.
(Edited)
Feb 1, 2019
arthast
2
Feb 2, 2019
bookmark_border
dandurstonThank you for such an informative reply.
Feb 2, 2019
Inertiaman
15
Feb 14, 2019
bookmark_border
dandurstonIf I do the trigonometry on a 48" pole versus a 46.5 pole, the base shifts 12", not 4-6". At what point does a longer pole become too long for this design? Given that the design requires inverted tips-up poles, the handles will become vulnerable to slipping at some point. I'm now realizing that the X-Mid may not work with my current poles (Black Diamond Z style non-adjustable) since they are 51" (I'm 6'3"). Such poles will need to be offset 21" = a 24deg angle. I'm skeptical that they would stay in place.
Feb 14, 2019
dandurston
5116
Dan Durston
Feb 14, 2019
bookmark_border
InertiamanFirst, kudos for actually doing the trigonometry. My 4-6" statement was an estimate that obviously wasn't that accurate. When I do the trigonometry I also get 11.9" base for right angled triangle with a 46.5" height and 48" hypotenuse. One thing to clarify is that the design doesn't require the poles to be tips up. It allows for this, but it can easily pitch handles up too. The grommets are located as high up as possible (without the tips damaging the tent) because that is better structurally (e.g. top of pole is closer to the peak where the main forces meet) but this also means it's no problem to pitch handles up. So you could pitch handles up, and also push your tips into the dirt by an inch or two which would have the advantages of (1) securing the bottoms of the poles in place and (2) shortening the height discrepancy. Certainly you don't want the bottom of the pole sliding out, but otherwise I don't think a 12" offset is a big concern structurally as my earlier diagram shows (e.g. the Nemo Veda is designed with what appears to be a huge offset - perhaps 25 - 30" - and reviews find it robust). One other variable is how high you pitch the tent. The fly has about 10" of cord at each corner which acts as basically an extension of the fly in a pitch. The length of this cord is adjustable (with LineLoc3's). I normally pitch it fairly short because I like my fly pretty close to the ground for maximal wind blocking, but most tents can't come this low to the ground so if you pitched it higher it would still be quite good here relatively. If you extend the cord you can lift the fly up so it pitches at more like 48 peaks. To sum it up, 51" poles is pushing it seemingly, although I haven't tried it. I suspect they would work fine if you used some or most of these tricks (handles up, dig the tip in an inch, maybe pitch it up an inch higher) but if you simply pitched it tips up normally that would be quite an angle on the pole and the handle would be at risk of slipping out.
(Edited)
Feb 14, 2019
View Full Discussion