While I've been momentarily distracted for a few years trying to figure out why single line kites (don't) fly- and thinking about the ultimate pilot kite, the world of traction kiting has expanded a lot, but apart from de-power foils becoming ever more dominant in buggying and snow kiting, it hasn't changed a lot.
Skin - 5.5 sq.m rigged for bar. Skin- 5.5 sq.m on a bar.
Time it did.
So, yes, I thought (about 2 years ago), single skin kites have untapped potential and sooner or later will take over significant bits of traction kiting- and open up some new areas as well.
I wasn't wrong about this trend either; judging by the large number of emails I've had from people of a like mind since I came out with the Skin design two newsletters ago. Many enthusiasts have been quietly working away on single skin developments for years - mainly with NASA style design variants (generally called NPW's).
And in the last 2 months, Ozone have shown photos of their prototype (I expected them to be first to market with a new single skin kite given their successful single skin parapent ), and Flysurfer have released their "Peak"- also a 'foil style traction kite that they've obviously been developing for some time. I've only seen photos of the Ozone version, but I expect that it will be a kite to reckon with, judging by other products they make. For Flysurfer's "Peak", there is an action video which can be viewed at http://vimeo.com/77198501 , and it looks pretty good to me- jumping even!
The Ozone and Flysurfer versions have wrapped around leading edges while the Skin doesn't have- and NPW's don't have either except in their centre sections. But rather than one or the other of these approaches being best, I expect their relative advantages and disadvantages will make these different styles complementary. Having a lower leading edge extending to say 10% or so of the chord dimension can be expected to improve L/D (upwind performance) so this style should have a good chance of competing with 'foils at the performance end. But they are more complex to make and the wrap-around also creates a pocket which might limit some snow and water applications. Even if the Skins have marginally lower L/D , their simplicity and other virtues will ensure they get a share of the market (and they already are, though this may just be initial curiosity).
It's all happening!
So what have I got to grump about?
Very simply, I like flying with handles, DONT like flying with a bar. And while I wasn't watching, it seems that the entire world took to using bars. Today's fliers can't use handles, they barely even recognise what they are.
And yet handles provide an extra dimension of control; every four line kite ever made flies better off handles than with a bar because handles allow one tip to be pulled in or let out relative to the other, whereas bars don't . Flying off a bar is like flying an aeroplane without being able to bank into turns. Steering is by applying the brakes one side or the other- like a bulldozer. How crude, how primitive!
But fliers overwhelmingly favour bars now so they can wave to the admiring crowds, and do showy board grabs -and possibly even things that would be best kept out of the public view- with the hand it frees up.
Watching current generation bar users trying to fly the Skins with handles has verged on the comical at times. Basically they just can't. Their problem is that the Skins are set up to require a fine balance between front and brake line tension. Fly completely off the front lines and they crumple their leading edge and won't steer, jerk aggressively on the brakes and they stall. The technique required is exactly what Rev fliers do - they dial into the Skins immediately- and won't give them back (especially when there's zero wind).
Not Enjoying Myself
But making good kitefliers look bad is not a path to acceptance for a new design, so having spent the last month taking every possible opportunity to do something else, today I rigged a 5.5 sq.m 5 cell Skin on a bar and went down the back to try it out.
The whinge is having to wear a ridiculous harness thingy- which wouldn't be at all out of place in a sex shop. Seeing as it's a chore getting into it, I tend to leave it on during the day while I'm doing testing- which occasioned strange looks when I delivered some files to our accountant's office this morning. Another problem with harnesses is weight- around 1.5kg, equivalent to two 3sq.m Skins complete with lines and handles- which will therefore be left behind every time I have to travel within a weight limit and need to take a harness. Also, you can't get your hands into your pockets (so at least I wont go blind).
And the flying?
It was hopeless, basically wouldn't fly at all- initially- but after an hour or so stuffing around with the rigging it's now not too bad- for a bar- and I never threw up either- surprising self control!.
Skin - Bridle for handles - de power mode.
Skin - Bridle for bar and beginner handles.
Actually, I learnt a few things which made this kite easier to fly even after I put it back on handles (in an attempt to un-grump myself before some visitors were due). In essence, (and this was suggested to me by one of the NPW experts I've begun corresponding with- thank you Ian ) it's to rig the brakes so they can't be let out by more than a set amount. This is done by adding a bridging line between each main bridle set and that side's brake set. With these bridging lines, the kite holds form when the brakes are fully released . Works a treat- and without adding any extra bridling.
The bridle and brake line lengths that seem to best suit this set-up are listed in the chart below and are retro-fit-able to Skins already supplied. The best length for the bridge lines that I've found so far are such that the flying line ends of all the bridles are exactly together when there is no brake line tension (see photos). This is a huge coincidence considering that it's critical within 20mm or so and there was no thought of using this style of rigging when the bridling was originally developed.
Bridle lengths for 5 cell 2.75 sq.m Skin at 29th October 2013: for handle and bar flying
- Tip bridles: 2.35m (both), tip brake: 2.52m difference: +170 mm
- Outer rib bridles: 2.50m (all) Outer rib brake: 2.70m difference: +200mm
- Centre rib bridles: 2.60m (all) Centre rib brake: 2.92m difference: +320mm
- Leaders/bridge lines: 4 required, each 750mm
And if the bridge lines are made up as per the photos, then the kite can be either rigged for bar flying (and no-brains handle flying for beginners) or for handle flying with de-power and zero wind capabilities.
Intriguingly, when rigged for bar flying the Skin is very close to flying 2 line as well - and does with a bit of extra bridle tweaking (because bridle lengths then become very critical- as for NPW's). Skin - 2.75sq.m Bar Bridle.
Skin - 2.75 sq.m De-Power Bridle
Intriguing, because I'm increasingly excited about how far this design can eventually go. Is it just an NPW with ribs: of commercial interest because it's simpler, cheaper, and easy to fly? Or will it carve out a new place for itself in kiting? I don't know yet, but I sure am enjoying finding out - and at least I now know what I'll be doing for the next 5 years or so.
And here's the moan: I'm not going to get as much time as I expected playing with all the great toys I've acquired in the last many years.
But then again, there's no "bugger" in C'est le vie (pardon my French).
Peter Lynn, Ashburton, New Zealand, November 1 '13
PS: for even more rabbit-ing on, try: