Date: Wed, 24 Feb 1993 09:31:25 GMT From: andrew@tug.com (Andrew Beattie) Message-ID: Organization: Negligible. Subject: Peels Someone wrote to me, asking about Peels. I think that my reply is woth posting. I acknowledge that including quotes of private Email is a breach of netequitte, but I think that the quotes are sufficiently innocuous that he/she won't mind. (And I havn't told you the name anyway) > I heard two things about the Peel: > 1. It is now made out of carrington r.s. nylon Is it? This is news to me. The usual Peel material is similar to the stuff used in Rev's. It is thick, waxy and the front and back surfaces are very different. I was under the impression that PL had chosen it carefuly for these properties. I think that Carrington may not be strong enough for the abuse that Peels tend to take. In fact I was thinking of asking him to make me a special racing Peel, with a one-way vent and rip-stop-repair-tape re-inforcing on the seams. As you get more experienced, you can shift the compromise between strength and weight to weaker and lighter as you learn not to do things that strain the foil. My special kite might give me an edge in racing, but a beginner would probably destroy it in a few minutes. (through ground contact) > 2. It has some sort of fancy bungee-bridle system that makes the > Peel have a 'more' constant pull throughout the wind window. This is the "Reefing" bridle. One of the things that a buggy racer designing kites needs to look at is the ratio between the maximum pull (usually at full speed through the middle of the window) and the minimum pull (usually when the foil is hovering at the edge of the window. The ideal Max-Min-Ration (MMR) is 1. Flexifoils have a very poor MMR. The pull hard in the middle (in fact, a single 10' foil doesn't quite pull enough unless you've got *loads* of wind) but at the edge, there is nothing there at all. If you stack enough flexies to give decent pull at the edge (perhaps 4 or even 6), you havn't got a hope when you fly it through the centre of the wind (together with the fact that a stack is more difficult to re-launch when you drop it). The Flexi is also two damned fast. You spend all your time weaving it round the sky, trying to catch the wind. The Peel is *much* slower. The Peel does two main things to aim for a MMR of 1. The foil has a kick-up in the tail. This gives extra lift when the wind speed is low but collapses when the wind speed is high. This gives extra pull at the edge. The new "Reefing" peels contain a special patented bridle. The bridle is split so there is one bridle that connect to every even cell and one bridle that connects to every odd cell. Because the two bridles are connected by a bungee chord, when the pressure increases, the canopy collapses into a concertina thus reducing it's effective size by up to 30 That description was inaccurate, in order to keep it simple. In fact the bridle attaches to ribs, not cells. Every other rib has no bridle attachment. The bungee chord is arranged to be pre-loaded. By changing the line attachment point you can disable the reefing feature. The bridle is of course split in two for each control line and each half has a bungee. The Reefing Peels are not much more expensive that the non-reefing Peels. I would advise anyone to go for the reefing option. > 1. Have you tried flying the smaller 360 cm Peel or the > Larger 640cm ? Peel? What do you think about these? The small peel doesn't come in a reefing version. You can fly it is just about as much wind as you dare. I think that Peter Lynn has travelled fastest with the smaller Peel. This is because: 1) the fastest speeds are attained in the strongest winds. Too big and you can't handle it. 2) as you get *really* fast (after a while in a straight line), with the medium Peel you stop weaving the sail and can hang it ahead of you in a fixed position. The thing just keeps getting faster and faster until the drag of the kite becomes a problem and the buggy starts to overtake the kite! The way out of theis problem is to take a *smaller* kite, spend longer (miles?) getting up to speed, but since you've got less drag, you can go faster in the long run. (I've not done a speed run myself - I've not even got a buggy yet, but I'll have one just as soon as I can afford it.) The large Peel is really built to take advantage of the Reefing. With a normal bridle, it would be too big for racing, but the reefing brings it down to the size of a medium Peel when the pressure builds up. In turn, the Medium reefer goes down to about the size of a small Peel. > 2. I noticed in the Peel advertisement that the minimum > wind range for the 5m Peel is about 3m/s. What kind of > pull (actually how strong of a pull) should I expect? > Will I be sliding across the ground in this type of wind > (assume avg weight for me) 3 meters per second? that's nearly 7 mph. You may need to use 300' of line on it to persuade it to drag you at that speed. With *skill* you should be able to fly it in about half that much wind. > BTW, My friend at the local kite shop has one of the buggies at his shop, > and offered me to use it once in a while (nice guy). Nice guy? Smart guy! Trying a buggy is a one-way route. Believe me you'll buy one :-) Andrew -- andrew@tug.com = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =