The111 1 #1 September 7, 2003 I recently bought a Pro-Track and tried it out for the first time on 4 sitfly solo jumps. In the Pro-Track log, all of them had an exit of about 13500 and a deployment of about 3300 (I'm assuming this is when I'm full seated since I dump at 4k). The freefall time recorded for each was about 57 seconds. It doesn't make much sense to me that I would average 5.7 seconds per thousand feet on a sitfly... I thought on your belly it was only 5 seconds? Any thoughts?www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
webracer 0 #2 September 7, 2003 This all depends on you. It logs until about the time your canopy is inflating, not until you're fully seated. Maybe you have a slow sitfly, or are kinda on your back, or maybe the protrack is wrong. Mine registers about 55-60 seconds from 13.5 to 2.2 where I am usually open. I do go a bit faster though, about 150. Do a belly jump and see what it reads. I usually get about 70 for the same altitude belly jump. TroyTroy I am now free to exercise my downward mobility. Quote Share this post Link to post Share on other sites
mjosparky 3 #3 September 7, 2003 QuoteThis all depends on you. It logs until about the time your canopy is inflating, not until you're fully seated. Maybe you have a slow sitfly, or are kinda on your back, or maybe the protrack is wrong. Mine registers about 55-60 seconds from 13.5 to 2.2 where I am usually open. I do go a bit faster though, about 150. Do a belly jump and see what it reads. I usually get about 70 for the same altitude belly jump. Troy If you are getting 70 sec. from 13.5 that means you are averaging 110/112 mph. Thats pretty slow? SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
The111 1 #4 September 7, 2003 Ok... I read in the documentation that for accurate speed measurements you should mount the thing on your foot or something. Mine is inside my helmet, so I wasn't expecting accurate speed measurements, but here's the worst thing. Apparently the software in this thing has no feature that checks "avg speed" vs time and distance of your freefall. For example on one jump I fell 10200 ft over 54 sec (both according to the Pro-Track). Simple math says I have avg speed of 128 mph. Which is way too fucking slow for a sit anyway and reinforces my belief that the time log is wrong. However, the "avg speed" according to the Pro-Track for that same jump is 145! Now that is a number I can believe... but what boggles my mind is not that the freefall time is obviously wrong... but that the freefall time, distance, and avg speed don't all match up!www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
Hazarrd 1 #5 September 7, 2003 Is this something that has been covered in other posts before? I recently purchased a Pro-Track. I was wondering how accurate it really is. Just curious if this is something that has been discussed before and is known to be an issue. For $300 the damn thing better work like a diamond. .-. Quote Share this post Link to post Share on other sites
Kris 0 #6 September 7, 2003 Are you using SAS or TAS? The time actually sounds about right compared to the sitfly dives I've done from 13K. Also, don't forget about the forward throw on exit. You don't immediately start doing terminal, it takes about 7-10 seconds to get off of the "hill".Sky, Muff Bro, Rodriguez Bro, and Bastion of Purity and Innocence!™ Quote Share this post Link to post Share on other sites
The111 1 #7 September 7, 2003 QuoteAre you using SAS or TAS? TAS. QuoteThe time actually sounds about right compared to the sitfly dives I've done from 13K. Also, don't forget about the forward throw on exit. You don't immediately start doing terminal, it takes about 7-10 seconds to get off of the "hill". Good point... I guess that explains the time issue... as far as the speed issue, maybe the Pro-Track is smart enough not to use the speed data from those first 7-10 seconds to calculate avg speed... which is why the numbers for freefall time and avg speed don't match up. Guess it all does kinda make sense... thanks.www.WingsuitPhotos.com Quote Share this post Link to post Share on other sites
Chrisky 0 #8 September 7, 2003 I've read somwhere that it takes the protrack about 5-7 sec before accurately logging the dive. This could be because the pressure change is not strong enough before that time. Maybe a standard "acceleration time" is later added to te exact data resulting in strange freefall times? Whatever, I've compared Data with others after n-ways and it pretty well matched up.The mind is like a parachute - it only works once it's open. From the edge you just see more. ... Not every Swooper hooks & not every Hooker swoops ... Quote Share this post Link to post Share on other sites
kallend 1,647 #9 September 7, 2003 QuoteOk... I read in the documentation that for accurate speed measurements you should mount the thing on your foot or something. Mine is inside my helmet, so I wasn't expecting accurate speed measurements, but here's the worst thing. Apparently the software in this thing has no feature that checks "avg speed" vs time and distance of your freefall. For example on one jump I fell 10200 ft over 54 sec (both according to the Pro-Track). Simple math says I have avg speed of 128 mph. Which is way too fucking slow for a sit anyway and reinforces my belief that the time log is wrong. However, the "avg speed" according to the Pro-Track for that same jump is 145! Now that is a number I can believe... but what boggles my mind is not that the freefall time is obviously wrong... but that the freefall time, distance, and avg speed don't all match up! Read the f------ manual! All is explained in there.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
Staso 0 #10 September 8, 2003 it doesn't measure your speed for first 10 or so seconds after exit and like 5 seconds before deployment. even when i have my average speed for the whole dive about 240 mph (speed dives) i still have about 40 seconds of freefall time. that will explain difference in average speeds you calculated and the average on the protrack display. don't blaim pro-track, it's a nice device :) stan. -- it's not about defying gravity; it's how hard you can abuse it. speed skydiving it is ... Speed Skydiving Forum Quote Share this post Link to post Share on other sites
sducoach 0 #11 September 8, 2003 How does it know 5 seconds before I deploy to stop reading? Man I thought my wife could read my mind!! Don't say it, I know, short story.............. I believe if you check, the unit backs up 200' prior to the last reading and indicates that altitude as opening altitude. Blues, J.E.James 4:8 Quote Share this post Link to post Share on other sites
Staso 0 #12 September 8, 2003 QuoteHow does it know 5 seconds before I deploy to stop reading? Man I thought my wife could read my mind!! Don't say it, I know, short story.............. I believe if you check, the unit backs up 200' prior to the last reading and indicates that altitude as opening altitude. Blues, J.E. after you deployed, it takes all the data 10 seconds after exit and 5 before deployment and ignores the rest. what's the problem ? numbers may be inaccurate. it could be 12 and 5 or somthing like that. it's all in the manual. opening altitude is determined as altitude where "significant decrease in vertical speed" was registred. stan. -- it's not about defying gravity; it's how hard you can abuse it. speed skydiving it is ... Speed Skydiving Forum Quote Share this post Link to post Share on other sites
