Date: Mon, 14 Nov 1994 21:56:12 -1000 From: andrew@tug.com (Andrew Beattie) Message-Id: Organization: /usr/lib/news/organisation Subject: Buggy Weight There has been passing reference to buggy weight here... The biggest problem with a heavy buggy is that the increased mass is more difficult to accelerate or decelerate. When starting, the power pulls the pilot both across (sideways and/or forward) and up. The upwards portion of the pull makes it particularly difficult to transfer the pull to the buggy, you tend, in particular to stand up on the foot-pegs (if this isn't a problem, then you simply arn't using a big enough kite...). Likewise, when you try to stop using the kite as a brake, the kite will stop you while the heavy buggy will be inclined to run away from beneath you. Idealy, all the mass should be in the pilot and none in the buggy. Hmmm... let me theorise a little... Let's presume that a short course is won or lost on acceleration and decelaration. (for simplification, we are assuming that everyone has much the same top speed and they arn't staying at it for long anyway) If the pilot weighs nothing, the kite won't fly, it'll just drift down the field. If the pilot is far too heavy, he's not going anywhere. A light guy (say a 7-year old), is limited to a smaller kite because the buggy is a significant portion of the buggy/corpse weight. He will tend to be pulled out of the buggy before he can get the buggy to accelerate. On the other hand, a more massive pilot (let's consider Mr Benson as an extreem example...) may put up a 10m kite and still not be over-powered. He cannot put up a bigger kite, because it would be too large to control. He does, however have the advantage that the buggy is a small portion of the buggy/corpse mass and will have little difficulty in getting the buggy to keep up with him. This leads to the conclusion that the acceleration advantage goes to the smallest pilot who can control a 10m kite on the day. The other limit is the traction limit. The heavier you are, the more sideways force you can put on the buggy before it slides. The buggy geometry is such that it is the rear that breaks away first. To counter this, you want the pull coming from near the front and the weight over the rear axle. Thus we can conclude that the winner will have long arms and a big bum. Andrew -- You can FTP the kite FAQ's from ftp.hawaii.edu (directory /pub/rec/kites/faq) /-\ () >< () |\/| () >< () /-\ For sale: 10' Flexis with std & UF Spars, 10m Peel (I want the new reefers) What should I know? I can't even axel yet :-( = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 16 Nov 1994 00:00:35 -1000 From: andrewh@phoenix.harvard.edu (Andrew Hawken) Message-Id: <3acl83$t41@beta.qmw.ac.uk> Organization: Queen Mary & Westfield College, London, UK Subject: Re: Buggy Weight [Andrew B. suggested that long armed pilots with big bums would win races. And lots of other stuff about relative weight of buggy and pilot...] Doesn't the addition of buggy hooks (such as on Andrew B's buggy) make the effective mass be a combinaiton of the pilot and the buggy, as the power is transfered to the frame and not to the pilot? In order to get around the big bum long arm thing, would it be possible to run the fly lines through buggy hooks nearer the front of the buggy then back to the handles ? Andy -- ____________________________Andrew Hawken______________________________ "However many ways there may be of being alive, it is certain that there are vastly more ways of being dead" R Dawkins. Home : 0895 420110 QMW : 071 975 5542 AIIT : 0494 677045 Email : A.Hawken@QMW.AC.UK = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =