IceWater 0 #1 November 12, 2009 For a new 'A' with less than 100 jumps - what type of line is good for a beginner chute? Thanks for the help & the votes!Life is not about how many breaths you take; but rather how many moments there are that take your breath away. Quote Share this post Link to post Share on other sites
JohanW 0 #2 November 12, 2009 The advantages of Spectra and HMA over Dacron are not things you would notice. Dacron takes the edge off harder openings, goes out of trim slower, and lasts longer. It packs a little larger though, because the lines are fatter. If it's lined with Spectra now and packs tight, get a rigger's opinion. If it's lined with Spectra now and doesn't need a reline, don't not buy it because it's not Dacron. But if you have the choice, go with Dacron (don't pay extra for it though).Johan. I am. I think. Quote Share this post Link to post Share on other sites
billvon 2,402 #3 November 12, 2009 For a larger Triathalon, dacron is a good choice. The drag penalty is not as high at larger sizes. Quote Share this post Link to post Share on other sites
faulknerwn 36 #4 November 13, 2009 I just installed dacron on my Triathlon 99. The openings seemed to be softer afterwards. I don't notice any reduction in speed. In fact the lines they shipped were so similar in size to the the original spectra that we had to compare them for a few minutes to make sure I got the right thing! W Quote Share this post Link to post Share on other sites
parachutist 1 #5 November 13, 2009 QuoteFor a new 'A' with less than 100 jumps HMA lines have damaged the sliders on both my Vision 117 and my VX109. I really dislike HMA for this reason. I much prefer Vectran because it doesn't shrink like Spectra, stretch like Dacron, or shred fabric like HMA. Aerodyne has a big hole in their offerings by not making Vectran available as an option on any of their canopies Quote Share this post Link to post Share on other sites JohanW 0 #6 November 13, 2009 QuoteFor a larger Triathlon, dacron is a good choice. The drag penalty is not as high at larger sizes.But a smaller one would have shorter lines, so the drag penalty would not be as high .. colour me stupid, but I don't get it. Does this assume equal wingloads or equal suspended weights?Johan. I am. I think. Quote Share this post Link to post Share on other sites pchapman 261 #7 November 13, 2009 QuoteQuoteBut a smaller one would have shorter lines, so the drag penalty would not be as high .. That's certainly a point. It gets messy though and I don't quite know the answer. There is often some assumption of higher wing loading for smaller canopies (as you suggested), and higher speed, where one cares more about drag. On the other hand one can ask why one cares more about drag of lines in particular, as the actual amount drag of everything goes up with speed? In that way lines can't be singled out. However, it seems so having less drag is more important for having the energy for a good flare, when dealing with higher wing loadings and speeds. (E.g., if one had to jump a Manta at 2.3 wing loading, one might care more about line type!) Also, due to the square-cube law type stuff, the line length will vary slower than the area. (E.g., scale a canopy down to half size in every dimension = half the line length but one quarter the area) So lines have relatively bigger for small canopies. This holds only because we don't scale lines down in thickness -- if one downsizes by one size one doesn't change 600 lb Dacron to 550 lb Dacron. The canopy is smaller but the lines are just as thick. So the answer isn't exactly clear cut, but I think in general there are still reasons to be more concerned about line thickness for smaller canopies. Quote Share this post Link to post Share on other sites timmyfitz 0 #8 November 13, 2009 QuoteQuoteFor a new 'A' with less than 100 jumps QuoteHMA lines have damaged the sliders on both my Vision 117 and my VX109. Quoteshred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. Quote Share this post Link to post Share on other sites parachutist 1 #9 November 13, 2009 QuoteQuoteQuoteFor a new 'A' with less than 100 jumps QuoteHMA lines have damaged the sliders on both my Vision 117 and my VX109. Quoteshred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. Quote Share this post Link to post Share on other sites timmyfitz 0 #10 November 14, 2009 Quote Quote Quote Quote For a new 'A' with less than 100 jumps Quote HMA lines have damaged the sliders on both my Vision 117 and my VX109 . Quote shred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. I can see your point. I guess the point I was trying to make is that if HMA was causing these types of problems consistently, we would have heard about it. But there are many things I have not heard of. There is obviously something peculiar going on in your case Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0 Go To Topic Listing
JohanW 0 #6 November 13, 2009 QuoteFor a larger Triathlon, dacron is a good choice. The drag penalty is not as high at larger sizes.But a smaller one would have shorter lines, so the drag penalty would not be as high .. colour me stupid, but I don't get it. Does this assume equal wingloads or equal suspended weights?Johan. I am. I think. Quote Share this post Link to post Share on other sites
pchapman 261 #7 November 13, 2009 QuoteQuoteBut a smaller one would have shorter lines, so the drag penalty would not be as high .. That's certainly a point. It gets messy though and I don't quite know the answer. There is often some assumption of higher wing loading for smaller canopies (as you suggested), and higher speed, where one cares more about drag. On the other hand one can ask why one cares more about drag of lines in particular, as the actual amount drag of everything goes up with speed? In that way lines can't be singled out. However, it seems so having less drag is more important for having the energy for a good flare, when dealing with higher wing loadings and speeds. (E.g., if one had to jump a Manta at 2.3 wing loading, one might care more about line type!) Also, due to the square-cube law type stuff, the line length will vary slower than the area. (E.g., scale a canopy down to half size in every dimension = half the line length but one quarter the area) So lines have relatively bigger for small canopies. This holds only because we don't scale lines down in thickness -- if one downsizes by one size one doesn't change 600 lb Dacron to 550 lb Dacron. The canopy is smaller but the lines are just as thick. So the answer isn't exactly clear cut, but I think in general there are still reasons to be more concerned about line thickness for smaller canopies. Quote Share this post Link to post Share on other sites
timmyfitz 0 #8 November 13, 2009 QuoteQuoteFor a new 'A' with less than 100 jumps QuoteHMA lines have damaged the sliders on both my Vision 117 and my VX109. Quoteshred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. Quote Share this post Link to post Share on other sites parachutist 1 #9 November 13, 2009 QuoteQuoteQuoteFor a new 'A' with less than 100 jumps QuoteHMA lines have damaged the sliders on both my Vision 117 and my VX109. Quoteshred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. Quote Share this post Link to post Share on other sites timmyfitz 0 #10 November 14, 2009 Quote Quote Quote Quote For a new 'A' with less than 100 jumps Quote HMA lines have damaged the sliders on both my Vision 117 and my VX109 . Quote shred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. I can see your point. I guess the point I was trying to make is that if HMA was causing these types of problems consistently, we would have heard about it. But there are many things I have not heard of. There is obviously something peculiar going on in your case Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0 Go To Topic Listing
parachutist 1 #9 November 13, 2009 QuoteQuoteQuoteFor a new 'A' with less than 100 jumps QuoteHMA lines have damaged the sliders on both my Vision 117 and my VX109. Quoteshred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. Quote Share this post Link to post Share on other sites timmyfitz 0 #10 November 14, 2009 Quote Quote Quote Quote For a new 'A' with less than 100 jumps Quote HMA lines have damaged the sliders on both my Vision 117 and my VX109 . Quote shred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. I can see your point. I guess the point I was trying to make is that if HMA was causing these types of problems consistently, we would have heard about it. But there are many things I have not heard of. There is obviously something peculiar going on in your case Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0
timmyfitz 0 #10 November 14, 2009 Quote Quote Quote Quote For a new 'A' with less than 100 jumps Quote HMA lines have damaged the sliders on both my Vision 117 and my VX109 . Quote shred fabric like HMA. I see you have had problems with HMA damaging your equipment. Not sure HMA is the root cause. I have nearly 2000 jumps on a few different canopy's with HMA and have not had any damage due to the lines. (just my anecdotal experience) I can't say for sure that HMA does or does not cause damage or line burns more than any other line type but to claim it shreds fabric might be a bit of hyperbole. I think it may be a good idea to look for other causes. The reason I'm drawing this conclusion: Both canopies had other line types originally: spectra on the Vision and vectran on the VX. Sliders were in great shape on both canopies. Then line sets were changed to HMA on both canopies. The VX shows minor hredding on slider only near the grommets where they rub lines on the way down. Damage to the Vision slider is much more obvious... the red slider is shredded much farther inboard. The only variable that changed for these 2 canopies was the type of line, and after both were changed to HMA, both showed similar damage to their sliders. I can see your point. I guess the point I was trying to make is that if HMA was causing these types of problems consistently, we would have heard about it. But there are many things I have not heard of. There is obviously something peculiar going on in your case Quote Share this post Link to post Share on other sites
