Foil´s vs. Lei´s
Every year again till we die
How boring, better go to sleep
the future is bright, the future is foil
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the_lone_wolf
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haha, here we go again 
Last edited by the_lone_wolf on Mon Apr 04, 2005 9:11 am, edited 1 time in total.
Why?How can anyone be serious about using a foil on the water? Maybe foil kiters dont want to progress? Sorry, but thats just gay.
If you could tell me why and give me a valid reason then I could take you seriously. I use foils and tubes on the water and I know exactly what each style of kite does well or does not do well.
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johnmelton
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In my expirience Flysurfers and Peter Lynn's work well on water. But now it's going to take 95% depower and much better turning speed to get me back on a foil, except for the 26m Psycho. However I do miss the long floaty jumps of foils though, gave me plenty of time to correct all my mistakes during takeoff!
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Pump me up
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Inflatables are vastly superior to ram airs, including in light winds. I've summarised the reasons for the superiority of inflatables:
1: Lift to drag ration (L/D)
- The highest L/D ratio is not always optimal. A high L/D ratio is critical in large kites because they move slowly. Large kites generate steady power but generally lose out in ability to turn suddenly and generate sudden upward pull.
- Because large rams have a HUGE "D" coefficient compared to inflatables, they are unable to generate the sudden upward power spikes.
- For this reason, large rams can pull steadily enough, but will ALWAYS lack the jumping ability of a large, quality 2005 inflatable.
-Small kites move rapidly and therefore have large power spikes. These kites are INTENTIONALLY designed to move slower by ram and inflatable manufacturers. The lack or presence of a leading edge/ram cells is really irrelevant in the small sizes since SLOWNESS is a virtue in these sizes. The things to look for in these sizes are luff curve, chord, aspect ration for aerodynamic handling.
2: Inertia
- Because large ram airs have a much larger mass of air in them (filling the pockets) their inertia is enormous. It is very difficult moving this mass of air across the sky to generate sudden power spikes and therefore lift. The inertia and slow turning makes a lot of modern moves (eg kiteloops) incredibly difficult, if not impossible. Large ram air kites like the Titan 21.5 contain OVER 11kg of air in their cells.
3: Rigidity
- Small inflatables are better than small rams because they have a semi-rigid structure. This improves consistency, stability of turning, and precision in handling. Kite makers like Naish, North, and Flexifoil are actually moving to make their kites MORE rigid by joining the struts firmly to the leading edge and by adding fifth lines.
-Rigidity also facilitates turning. Bar pressure TWISTS the WHOLE kite, speeding up turns. Lack of internal rigidity means that rams can't twist as aerodynamically as inflatos.
4: Wing tips
- Far from being a hindrance, the tips of the inflatable act as rudders, enabling faster, more controlled turns (and therefore larger more controlled power spikes)
5: Foil shape
- Inflatables have a consistent foil shape because they are semi rigid. Rams deform and change their foil shape which causes an inconsistent aerodynamic profile.
6: Luff curve
- Luff curves vary extensively. Inflatables with flat luff curves sit forward in the window whereas inflatables with deeper luff curves sit further back in the window. It is the same principle as sailing: If you want more "bottom" end with a sail, you deepen the luff curve (eg letting out the outhaul on a sailboard). If you want more "high" end, you make the luff curve shallower (eg sheeting in the outhaul on a sailboard). There is a lot of difference amongst kites when it comes to luff curves and it determines a lot of handling characteristics. It's a matter of trying different inflatables until you find one you like.
- Because rams sit further back in the window than equivalent inflatables (due to excessive drag and inertia) there is less room for ram designers to play around with the luff curve.
7: Relaunch
- Ram lovers make a big issue of this. It isn't a big issue. Beginners find relaunching inflatables easy after a few sesssions. Yes, some rams can reverse launch, but so what... a lot of inflatables can reverse launch. Rams can launch directly downwind in the water, but so what... so can a lot of inflatables. Anyway, downwind launches are dangerous for beginners because of the risk of being flung or carted downwind. For intermediates and above, relaunching should not even be considered in the equation because a) they won't be dropping the kite much anyway and b) Relaunching inflatables is EASY
8: Safety
- Inflatables are safer than ram airs because
-- Downwind launches are bloody SCARY for a beginner
-- Rams deform, twist, wineglass, explode in the middle of the power zone etc when they are downwind of obstacles, in rotors, and in VERY gusty conditions. This is VERY dangerous. Some of the most frightening kitemares ever witnessed have involved ram users walking along beaches in cross-offshore conditions - their kites have been virtually uncontrollable and have endangered both the rider and other beach users.
-- Wind dropouts and gear failure
--- You will invariably experience a few gear failures (eg broken lines) and COMPLETE wind dropouts every year. If you are a fair way offshore, you can use the inflatable as a "sail" to get back in. Alternatively you can use the inflatable structure to support your weight.
--- All ram airs become hopelessly waterlogged after 45 minutes - unlaunchable and certainly unable to support your body weight.
-- Surf conditions
---While it is always a gamble if your kite gets caught by a wave, at least you've got a fighting chance if it is an inflatable. If it is a ram air, it's all over.
-- Bridle tangles and failures - Scary and expensive (US $500 plus) (eg see thread on this forum: "Flysurfer Warrior Exploding")
9 Pre-inflating
- Ram users struggle to pre-inflate their kites in a lot of situations eg cross- offshore conditions.
- Without pre-inflation, ram users find it very difficult to drift launch. This skill is often required eg Promontory/headland launches.
10 Resale
- Contrary to the propaganda of ram lovers, ram airs and inflatos have similar lifespans. The major determinant of a kites lifespan is obsolescence - in 2-3 years, whatever you're using now won't be worth much and will have been superseded.
11 Repairs
- Ram air repairs are generally a LOT more expensive. For example, most Flysurfer kites require a dedicated PARACHUTE repairer to do the job properly (eg bridle failures). The cost for this can be astronomical (thousands of dollars).
12 Competition
Ram lovers can't prove their claims in competitions. Whenever they make some ridiculous claim about how their kites will do well in competitions, they get blown out of the water. For example, they said that various kites from Flysurfer would dominate the pro kitesurfing circuit. It didn't happen. No ram riders made it into the top 50. They said ram airs would dominate the Cabo Verde Wave event... it didn't happen. Rams are aerodynamically inferior - they can't match it with inflatables in comps. The top pro riders ALL prefer inflatables because of their superior aerodynamic properties.
Ignore the ram air propaganda. Ignore the lies. Ram airs are aerodynamically inferior to LEIs and nothing can change this.
1: Lift to drag ration (L/D)
- The highest L/D ratio is not always optimal. A high L/D ratio is critical in large kites because they move slowly. Large kites generate steady power but generally lose out in ability to turn suddenly and generate sudden upward pull.
- Because large rams have a HUGE "D" coefficient compared to inflatables, they are unable to generate the sudden upward power spikes.
- For this reason, large rams can pull steadily enough, but will ALWAYS lack the jumping ability of a large, quality 2005 inflatable.
-Small kites move rapidly and therefore have large power spikes. These kites are INTENTIONALLY designed to move slower by ram and inflatable manufacturers. The lack or presence of a leading edge/ram cells is really irrelevant in the small sizes since SLOWNESS is a virtue in these sizes. The things to look for in these sizes are luff curve, chord, aspect ration for aerodynamic handling.
2: Inertia
- Because large ram airs have a much larger mass of air in them (filling the pockets) their inertia is enormous. It is very difficult moving this mass of air across the sky to generate sudden power spikes and therefore lift. The inertia and slow turning makes a lot of modern moves (eg kiteloops) incredibly difficult, if not impossible. Large ram air kites like the Titan 21.5 contain OVER 11kg of air in their cells.
3: Rigidity
- Small inflatables are better than small rams because they have a semi-rigid structure. This improves consistency, stability of turning, and precision in handling. Kite makers like Naish, North, and Flexifoil are actually moving to make their kites MORE rigid by joining the struts firmly to the leading edge and by adding fifth lines.
-Rigidity also facilitates turning. Bar pressure TWISTS the WHOLE kite, speeding up turns. Lack of internal rigidity means that rams can't twist as aerodynamically as inflatos.
4: Wing tips
- Far from being a hindrance, the tips of the inflatable act as rudders, enabling faster, more controlled turns (and therefore larger more controlled power spikes)
5: Foil shape
- Inflatables have a consistent foil shape because they are semi rigid. Rams deform and change their foil shape which causes an inconsistent aerodynamic profile.
6: Luff curve
- Luff curves vary extensively. Inflatables with flat luff curves sit forward in the window whereas inflatables with deeper luff curves sit further back in the window. It is the same principle as sailing: If you want more "bottom" end with a sail, you deepen the luff curve (eg letting out the outhaul on a sailboard). If you want more "high" end, you make the luff curve shallower (eg sheeting in the outhaul on a sailboard). There is a lot of difference amongst kites when it comes to luff curves and it determines a lot of handling characteristics. It's a matter of trying different inflatables until you find one you like.
- Because rams sit further back in the window than equivalent inflatables (due to excessive drag and inertia) there is less room for ram designers to play around with the luff curve.
7: Relaunch
- Ram lovers make a big issue of this. It isn't a big issue. Beginners find relaunching inflatables easy after a few sesssions. Yes, some rams can reverse launch, but so what... a lot of inflatables can reverse launch. Rams can launch directly downwind in the water, but so what... so can a lot of inflatables. Anyway, downwind launches are dangerous for beginners because of the risk of being flung or carted downwind. For intermediates and above, relaunching should not even be considered in the equation because a) they won't be dropping the kite much anyway and b) Relaunching inflatables is EASY
8: Safety
- Inflatables are safer than ram airs because
-- Downwind launches are bloody SCARY for a beginner
-- Rams deform, twist, wineglass, explode in the middle of the power zone etc when they are downwind of obstacles, in rotors, and in VERY gusty conditions. This is VERY dangerous. Some of the most frightening kitemares ever witnessed have involved ram users walking along beaches in cross-offshore conditions - their kites have been virtually uncontrollable and have endangered both the rider and other beach users.
-- Wind dropouts and gear failure
--- You will invariably experience a few gear failures (eg broken lines) and COMPLETE wind dropouts every year. If you are a fair way offshore, you can use the inflatable as a "sail" to get back in. Alternatively you can use the inflatable structure to support your weight.
--- All ram airs become hopelessly waterlogged after 45 minutes - unlaunchable and certainly unable to support your body weight.
-- Surf conditions
---While it is always a gamble if your kite gets caught by a wave, at least you've got a fighting chance if it is an inflatable. If it is a ram air, it's all over.
-- Bridle tangles and failures - Scary and expensive (US $500 plus) (eg see thread on this forum: "Flysurfer Warrior Exploding")
9 Pre-inflating
- Ram users struggle to pre-inflate their kites in a lot of situations eg cross- offshore conditions.
- Without pre-inflation, ram users find it very difficult to drift launch. This skill is often required eg Promontory/headland launches.
10 Resale
- Contrary to the propaganda of ram lovers, ram airs and inflatos have similar lifespans. The major determinant of a kites lifespan is obsolescence - in 2-3 years, whatever you're using now won't be worth much and will have been superseded.
11 Repairs
- Ram air repairs are generally a LOT more expensive. For example, most Flysurfer kites require a dedicated PARACHUTE repairer to do the job properly (eg bridle failures). The cost for this can be astronomical (thousands of dollars).
12 Competition
Ram lovers can't prove their claims in competitions. Whenever they make some ridiculous claim about how their kites will do well in competitions, they get blown out of the water. For example, they said that various kites from Flysurfer would dominate the pro kitesurfing circuit. It didn't happen. No ram riders made it into the top 50. They said ram airs would dominate the Cabo Verde Wave event... it didn't happen. Rams are aerodynamically inferior - they can't match it with inflatables in comps. The top pro riders ALL prefer inflatables because of their superior aerodynamic properties.
Ignore the ram air propaganda. Ignore the lies. Ram airs are aerodynamically inferior to LEIs and nothing can change this.
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Carlos_C
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But don't inflatables always have to be prinflated...dodgy launch or not??? what's your point ?9 Pre-inflating
- Ram users struggle to pre-inflate their kites in a lot of situations eg cross- offshore conditions.
- Without pre-inflation, ram users find it very difficult to drift launch. This skill is often required eg Promontory/headland launches.
.the only kites that don't are c quads and nasa wings
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