*


All times are UTC + 1 hour



Post new topic Reply to topic
 [ 133 posts ]  Go to page Previous  1, 2, 3, 4, 5 ... 14  Next
Author Message
 Post subject:
PostPosted: Thu Jun 19, 2003 12:02 am 
Offline
Very Frequent Poster
User avatar

Joined: Wed Oct 16, 2002 1:00 am
Posts: 1549
Location: Dublin, Ireland
At the end of the day, no matter what anyone says.
i'll continue to fly lei's simply because this is what i like to use and what i feel comfortable with. i dont think that any of the foil v leis arguments will ever change anbody minds.


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 12:53 am 
Offline
Very Frequent Poster

Joined: Fri Jan 24, 2003 1:00 am
Posts: 700
Inflatables are vastly superior to ram airs.

Why do ram lovers make patently ridiculous, over-the-top claims like "Chris Calthrop doing 8m jumps in 8 knots." It is just not possible... ram lovers making such ridiculous statements only serves to draw attention to the inadequacies of rams - if you have to lie about them, they can't be much good.

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 output steady power but generally lose out in ability to turn suddenly and generate sudden upward pull.

- Because large rams (eg Warrior 16.5) 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 2003 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 cranking 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.

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 and Flexifoil are actually moving to make their kites MORE rigid by joining the struts firmly to the leading edge.

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
- If you want a flat luff curve, choose an X2 or similar
- If you want a deep luff curve, choose a Rhino2 or similar
- If you want in-between, choose a Slingshot or similar
- Because rams sit further back in the window than equivalent inflatables (due to drag) they "feel" a bit like the R2, but without the other benefits of an inflatable.

7: Relaunch
- Ram lovers make a big issue of this. It isn't a big issue. Beginners find relaunching inflatables a cinch after a few sesssions. Just make sure you choose an inflatable that is easy to relaunch (eg Toro). Yes, rams can reverse launch, but so what? Rams can launch directly downwind in the water, but so what? This is dangerous for a beginner, if anything, because it increases the chances of being flung or carted.

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 I've seen have involved ram users walking along beaches in slightly 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 catastrophic 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 sail 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 hammered by a wave, at least you've got a chance if it is an inflato. If it is a ram air, it's curtains.
-- Bridle tangles and failures - Scary (eg see thread: Flysurfer Warrior Exploding)

9 Pre-inflating
- Ram users struggle to pre-inflate their kites in a lot of situations eg slightly offshore conditions.
- Without pre-inflation, ram users find it very difficult to water launch. This skill is often required eg downwind of promontories.

10 Resale
- Contrary to the propaganda of the 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 Competition
At the start of this year, ram lovers held up the Psycho as the salvation of rams in comps. They said that the Psycho would dominate comps and prove its worth on the PKRA and KPWT. It hasn't happened. No ram riders are in the top 50 on either tour. Rams are aerodynamically inferior - they can't cut it in comps.

Ignore the ram propaganda. Ignore the lies. No kite can jump in 8 knots. Rams are aerodynamically inferior to LEIs and nothing can change this.


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 8:01 am 
Offline
Very Frequent Poster

Joined: Tue May 06, 2003 10:29 am
Posts: 775
Location: Hawaii
Foils :argue: Inflatos


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 8:47 am 
Offline
Medium Poster
User avatar

Joined: Mon Mar 17, 2003 12:16 pm
Posts: 77
PMU you sad troll, why don't you just link to your previous drivel instead of cutting and pasting it all over the shop.

Go and play with you pump (geddit?) and leave the serious debate to the grown ups.


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 9:01 am 
Offline
Very Frequent Poster

Joined: Tue May 06, 2003 10:29 am
Posts: 775
Location: Hawaii
Cockney lad wrote:
PMU you sad troll, why don't you just link to your previous drivel instead of cutting and pasting it all over the shop.

Go and play with you pump (geddit?) and leave the serious debate to the grown ups.


PMU is not the troll!!

He was gone and quiet,but some trolling foil freak had to go trolling and bait him !

PMU U R DA MAN !


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 9:52 am 
Offline
Very Frequent Poster
User avatar

Joined: Fri Nov 08, 2002 1:00 am
Posts: 652
Location: Not where its bloody cold...
oh yes and about foils not wining hangtime contests, how about in australia with steffan cook coming second behind robbie naish in hang time comps on f arcs
robbie naish with 6.51 seconds and steffan cook with 6.05 seconds......

and he also won a few as well, also if th efoil idea is useless what about a number of lei companies experimenting with a bottom skin? obviously lei manufactorers have nothing to learnand pump me up is mr troll, .....when i was a child i remember having those cute trolls that had purple frizzy hair, quite amusing, espicially when we cut their hair... Pump me up show some credentials and lets see proof of your knowledge, i want to see certificates and qualifications proving you know what you say.......or at least experience at a manufacturer for a number of years desgining kite therefore a wealth of experience.....


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 10:12 am 
Offline
Very Frequent Poster

Joined: Fri Jan 24, 2003 1:00 am
Posts: 700
Alf wrote:
Then why is k48 spending approx. 50% of his time on the Storm2 ????


K48 is spending much more than 50% of his time on the Storm 2 - it's more like 95%. The other 5% is for promotional reasons alone.


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 10:49 am 
Offline
Frequent Poster
User avatar

Joined: Tue Feb 26, 2002 1:00 am
Posts: 318
Location: Holland
Well, the flexi representative I spoke said it was about 50-50.

And for Stefan Cook, I saw him earlier this year getting indeed rediculous hangtime (consistently) on the G-Arc. But the thing is, that the inflato-riders were doing tricks. the G-Arc goes big, but does not seems fit for tricks... And whenever the inflato guys were going for big-air they normally had a little less hangtime, but their highest hangtime was a little longer than Cook on the G-Arc.

I must admit I was impressed by his jumps on the G-Arc. But the kite didn't seem as allround as inflato's.


Top
Profile
 Post subject:
PostPosted: Thu Jun 19, 2003 11:23 am 
Offline
Frequent Poster
User avatar

Joined: Tue Feb 11, 2003 10:42 am
Posts: 306
Location: uk
wakeboy wrote:
and he also won a few as well, also if th efoil idea is useless what about a number of lei companies experimenting with a bottom skin? obviously lei manufactorers have nothing to learnand pump me up is mr troll, .....


Exactly.

I mean, hell are we arguing about the shape of the profile ( the wing shape from leading edge to trailing edge ) ?? Is that what this argument is about? Single skin vs two skin?

Or different profile shapes? Hell, every kite out there has a different shaped profile.

Arc's and gurilla's blend the shape of a LEI and two skins... but use a good profile shape so the 10 meter g-arc has less power than an 8 meter LEI.... so it seems they have the high end sorted, while LEI's are still looking for that good high wind profile....

So what is this argument about?

Single Skin vs Two Skin?
Ram Air Inflated vs Pump Inflated?

If you're keen to carry on the LEI vs ram air, then please back up everything you say with XFOIL analisys. Cheers!

john.e.boy


Top
Profile
 Post subject:
PostPosted: Mon Jun 30, 2003 12:43 pm 
Offline
Very Frequent Poster
User avatar

Joined: Tue Nov 05, 2002 1:00 am
Posts: 8736
well regarding mr calthrop, he was down at our local event this weekend and he spent all of his time out on blades.

he likes his blades he does, perhaps he gets a cent for each one sold...


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic
 [ 133 posts ]  Go to page Previous  1, 2, 3, 4, 5 ... 14  Next

All times are UTC + 1 hour


Who is online

Users browsing this forum: Bing [Bot], Google [Bot], mr moon, Rbgar, unbob and 24 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group