voodew1 0 #1 December 5, 2005 I don't use one nor do anyone I know but I would like to know why it is not recommended to use one. I am sure there is low pressure over the back and a slightly higher pressure under the chest..........but I can't see that it is enough to really make a difference. And if anything the reading would be slightly higher not lower which I would be ok with Has any one actually tried to compare wrist to chest and see what kind of difference there is. The reason for the question is I was approached by a jumper who only uses a chest mount alti and it made me think do I really want to tell him he can't use the altimeter he has been using for the last 4,000 jumps?? The pimp hand is powdered up ... say something stupid Quote Share this post Link to post Share on other sites
The111 0 #2 December 5, 2005 I didn't know it wasn't recommended - is this for all skydiving or for WS flight only? If it's for all skydiving, that doesn't make any sense because I know a lot of very experienced people who do that. If it's for WS flight only, I'm still confused, because I didn't know anybody had 4,000 WS flights yet. It's actually funny you made this post today because I was thinking about buying a chest mount today or tomorrow. I spent this whole weekend jumping with Scary Perry and some other Zflockers, and Perry and another guy ("My eyes" Jeff) both had chestmounts and were raving about them, especially for backflying, which I'm spending a lot of time doing now. Perry even had his student chestmount her alti. I use a Neptune on my wrist and have an old Galaxy that just sits around and collects dust, so I could spend a couple bucks and put it on my chest no problem. Then I could easily make some jumps in different orientations and compare numbers - I'll post my results. www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
notsane 0 #3 December 5, 2005 For belly flying a chest mounted altimeter is just fine, but for most everything else the alitmeter will be in the burble at some point. I'm sure that wingsuit backflying with a chest mounted altimeter would give you readings that are too high because of the lower pressure. I had a friend in the early 80's that nearly bounced because he was depending on a chest alimeter while falling on his back. The easiest way to check this out is to use 2 Neptunes .. 1 wrist mounted and the other chest mounted. Alternate flying belly first and back first for the dive, then download and compare the graphs. If you want to try it this weekend Matt I'll provide the 2nd Neptune. Scott Quote Share this post Link to post Share on other sites
Costyn 0 #4 December 5, 2005 QuoteAnd if anything the reading would be slightly higher not lower which I would be ok with Sorry to nitpick, but if there is a higher pressure region on your chest, and this is where your altimeter is located, it will indicate a lower altitude than what you really are at. Or is this what you meant? And Notsane's idea with the neptune is an excellent idea. I'd be pretty interested in the results too. Cheers, Costyn.Costyn van Dongen - http://www.flylikebrick.com/ - World Wide Wingsuit News Quote Share this post Link to post Share on other sites
LouDiamond 1 #5 December 6, 2005 We had this discussion a while back, the thread is out there somewhere still. I conducted tests with a chest mounted analog and digital altimeter over a series of 10 jumps. I wore a digital alti on my left wrist, a SUUNTO on my right and I had my GPS all as a means to measure against the alti on my chest. Long story short, the readings varied depending on the flight with the analog being the most affected, meaning giving a false reading as well as the Digital but to a lesser extent. The deviation was as low as 500 feet off and as high as 1000 feet off on 2 seperate but consecutive jumps with the other 8 jumps having a deviation of anywhere in between those two extremes. IMO, there isn't a good reason why you should wear your alti on your chest,(especially when we already know that it can read wrong when worn in this position) instead of on your wrist. The altitude deviations I saw ranged randomly depending on the flight and were large enough that they could potentially put you in a bad situation. I will caveat this by saying I know several people who use chest mounts with no discernable problems and they are aware that they sometimes get erroneous readings. Again, I think it is a poor choice to make when there is nothing to be gained by it's being placed there and the fact that a erroneous reading is a very high likelyhood."It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
avenfoto 0 #6 December 6, 2005 Quotenothing to be gained by it's being placed there in max distance position your chest should be in your chest, looking more where youve been then where youre going.... hence the reasoning behind a chest miunt alti on a ws jump.... match this w/an audible or two and i think you have a fairly solid setup.... Quote Share this post Link to post Share on other sites
voodew1 0 #7 December 6, 2005 I asked this question as to why not wear a chest mount alti (I can see lots of reasons why it would be easier to read a chest mount) I personally don't look at my alti until under canopy In the FAQ at the top of this page and from what I have been told and what I teach is it is not recommended to use a chest mount-------I want to know how far off will the readings be --- I don't see how it could be that much (unless you were backflying) The pimp hand is powdered up ... say something stupid Quote Share this post Link to post Share on other sites
LouDiamond 1 #8 December 6, 2005 QuoteQuotenothing to be gained by it's being placed there in max distance position your chest should be in your chest, looking more where youve been then where youre going.... hence the reasoning behind a chest miunt alti on a ws jump.... match this w/an audible or two and i think you have a fairly solid setup.... I agree with the chin on chest position when in a maxed out position. However, I and everyone else on the planet is capable of moving their eyes without having to turn their head enough to be able to see an altimeter mounted on their hand if it is rotated towards their thumb, as it should be for WS flights. Again, if your chin is on your chest and your altimeter on your chest strap, what does that put directly in front of your altimeter? The answer is your head of course and that can have a detrimental effect on the altimeter reading correctly. If holding a maxed out body position is that important that one cannot take a few seconds to peek at ones wrist alti then perhaps dual audibles (primary and alternate) a wrist mount( contingency) and most important out of them all, ones eyes(emergency) could be used. The only thing I mount on my chest strap is my larger GPS receivers( Vista, etc) and that is strictly for data collection and post flight analysis when I don't have time to helmet mount the receiver."It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
SCARYPERRY 0 #9 December 6, 2005 when flying cam, its a GENERAL referance, if I need to go to back at say 8000 ft i switch eyes and no cam wobble!!! instead of looking at hand, and then again??? if all belly flyers had same issue when tracking??? Still trust my eyes and wait till I smell dirt to pull!!Only he can be happy,who can make his the present hour,for today he has lived Quote Share this post Link to post Share on other sites
ernokaikkonen 0 #10 December 6, 2005 QuoteI am sure there is low pressure over the back and a slightly higher pressure under the chest..........but I can't see that it is enough to really make a difference. And if anything the reading would be slightly higher not lower which I would be ok with The explanation I've come up with is: -When you're flying with your head up, the altimeter reads correct(but you can't see the alti). -When you look at the alti, your head gets in the way of a clean airflow. Essentially, the alti ends up in a burble created by your head, not relative to your vertical speed but your horizontal speed. Or a bit of both. See attached picture. Quote Share this post Link to post Share on other sites
notsane 0 #11 December 6, 2005 I never look at mine either until I'm under canopy. Wouldn't it be sweet if we had an audible that announced the altitude every 2K or so. Right now I've got my audible (Neptune) programmed for 5K and 3.5K beeps. Quote Share this post Link to post Share on other sites
The111 0 #12 December 6, 2005 QuoteWouldn't it be sweet if we had an audible that announced the altitude every 2K or so. I get pretty close to that. I have ProTrack left ear and ProDytter right ear. I get 4 warnings. Left@9k, left@6k, [email protected], right@4k, and dual [email protected]. No, I don't depend on the audible, I watch the ground and I know what 4k looks like. www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
LukeH 0 #13 December 6, 2005 dude... 1 ProTrack, 1 ProDytter and 1 Neptune! (Is that where the name comes from?) You've gone gadget crazy. all these things beeping at me in freefall would piss me off. i sold my ProTrack over 150 skydives ago. If you don't depend on the audible why do you have two and why all the different beeps? Do you get lonely if you don't hear some electronic noise every few seconds? How did those poor skydivers ever survive back in the days before this junk. You are in for a shock when you start base jumping Quote Share this post Link to post Share on other sites
The111 0 #14 December 6, 2005 QuoteYou are in for a shock when you start base jumping You mean BASE and skydiving are different?www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
unclecharlie95 3 #15 December 6, 2005 QuoteYou mean BASE and skydiving are different? BASE is just like skydiving except with out the good bits... -only 1 parachute -1 hour pack jobs -you have to hike & climb up to exit altitude -1/2 the air space -boring canopy -crap landing areas -hardly any chicks -greatly increased risk of injury and death ... BASEstore.it Quote Share this post Link to post Share on other sites
pbla4024 0 #16 December 6, 2005 But rigs look much better. Ps.: 1 hour pack job? You are damn fast :-) Fido Quote Share this post Link to post Share on other sites
LukeH 0 #17 December 6, 2005 Quote You mean BASE and skydiving are different? Aparently if you go to a big cliff then jumping off is just like a skydive. The new trend is to put on a wingsuit as soon as possible as it's clearly safer. If you are far away from the cliif you can't hit it right! James has just the spot to combine your first Base jump and WS base jump. Quote Share this post Link to post Share on other sites
unclecharlie95 3 #18 December 6, 2005 Quote James has just the spot to combine your first Base jump and WS base jump. Best not to go there Come prepared and be welcome, otherwise stay home and train. Don't put your life and rare legal objects at risk.BASEstore.it Quote Share this post Link to post Share on other sites
The111 0 #19 December 6, 2005 QuoteCome prepared and be welcome, otherwise stay home and train. Don't put your life and rare legal objects at risk. Hey man, I have DYTTERS, I am prepared!!!www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
unclecharlie95 3 #20 December 6, 2005 QuoteHey man, I have DYTTERS, I am prepared!!! and a Cypres? BASEstore.it Quote Share this post Link to post Share on other sites
LouDiamond 1 #21 December 7, 2005 QuoteWouldn't it be sweet if we had an audible that announced the altitude every 2K or so Once it is released, the Titan will be the answer to this issue as all one has to do is shift their focus to the HUD to see anything from altitude, glide ratio, etc at any point in the flight."It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
phoenixlpr 0 #22 December 7, 2005 QuoteAparently if you go to a big cliff then jumping off is just like a skydive. BASE is not a skydive. PERIOD. If you are just talking about it, its quite lame. If you even BASE jump with that attitude you are going to get on the list, sooner or later. What list? The Base fatality list..... Quote Share this post Link to post Share on other sites
unclecharlie95 3 #23 December 7, 2005 Luke's post should be read out loud with a very sarcastic voice BASEstore.it Quote Share this post Link to post Share on other sites
The111 0 #24 December 7, 2005 Quote Luke's post should be read out loud with a very sarcastic voice Oh crap, I flew to Norway and made some BASE jumps yesterday, because of that post. Thanks a lot, guys!www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
jakee 1,254 #25 December 7, 2005 QuoteOh crap, I flew to Norway and made some BASE jumps yesterday, because of that post. Thanks a lot, guys! I hope you didn't track for very long, so that you could pull high. Y'know, for safety.Do you want to have an ideagasm? Quote Share this post Link to post Share on other sites
