From Usenet. Our esteemed engineer, Chuck Rogers offers some advice. In article <11652@tekig7.PEN.TEK.COM> bradl@tekig5.pen.tek.com writes: > >With the exception of BMW System and the odd Bieffe >hinged-mandible-helmet wearer, the rider afflicted with a full-face >helmet cannot readily eat an ice cream cone. Well, it depends on what you mean by "readily" and "eat", doesn't it? Rather than trot out the Hurt Study and beat you about the head and shoulders with it, I'll suggest instead that you try this simple experiment developed by the reknowned safety researchers of the DoD, and easily attempted by anyone on the planetary surface except Dick Floyd, Joan Claybrook, Homer Simpson, and Lance Holst. Step 1. Select your favorite size and flavor of ice cream on either a standard or a sugar cone (careful analysis has shown any differences in cones or flavors have no significant effect on the outcome of the test.) Step 2. Assemble/Install/Stick/Attach/Ploop your helmet onto your head, and fasten the chin strap as if you were preparing to ride. Step 3. Open the visor to its widest aperture and lock it there. If it will not remain securely open by itself, do not proceed further with this test, since horrible and grisly outcomes may be likely, and the DoD lacks sufficient worldly resources to serve as a litigation target. Step 4. Grasp the ice-cream cone firmly by the base in your (gloved, of course) hand-of-choice, and slam it directly into the center of the viewport as quickly as you can, before your natural reflexes take over and cause your head to dodge out of the way. It is *extremely* important that you target the *center* of your viewport. If, like many novices, you try to slip it in the side, your peripheral vision will sense the movement, and will direct your brain to cause your other hand to intervene, saving you from the impact, but wrecking the experiment. Step 5. Remove the helmet, and quickly, before the ice-cream impact profile, (ICIP) or "splat" deforms beyond useful information retrieval, mark the outline of the ICIP with an indelible marker or exacto knife. Step 6. Remove your helmet (unfasten the chin strap first) and wipe the mess off your face with a balaclava or some other suitable absorbent material. At this point, if you didn't follow directions properly when instructed to grasp the *base* of the ice-cream cone, you'll find numerous small slivers of cone-material imbedded in your face, and your carefully outlined ICIP will be rendered useless for any coherent research purposes. You may attempt to re-run the experiment starting at step 1, but your success at following written procedures doesn't bode well for even a modicum of success further on, so you probably should select some activity a bit less challenging. Why don't you read a little Netnews or something? Step 7. Those who managed to grasp the proper end of the ice-cream cone, and who have removed all experimental traces save the ICIP outline from the target area, may now proceed as follows: select another ice-cream cone identical in size and composition to the first, and grasp it by the *base*, as before. Now open your mouth as you would to orally acquire the business end of an ice-cream cone, close your eyes, visualize the viewport area of your helmet, and slam the ice-cream cone into the center of the visualized viewport, as before. Step 8. Quickly, mark the outline of the Second ICIP, preferably via the same mechanism previously employed, so that the two ICIP outlines will be simultaneously distinguishable. Clean up the mess, as before, then go to step 9. Step 9. Calculate the area of the region of your face covered by those portions of the two ICIPs *outside* the intersection of both ICIPs. Yes, it's not a rectangle, but somewhere in all that calculus you had to take, there must be something that will do this. (If you used the exacto knife instead of the indelible marker, your task is easier: just peel off the thin strips of face material, lay them on a rectangular grid of engineering graph paper, and calculate the area via the partial rectangles method.) If your earlier success in selecting cone-ends was a fluke, and you now find that you have a handfull of ice-cream and a face full of cone slivers, go over there and sit on that bench next to the giggling fellow with the laptop. No, no, we don't want the ice-cream back, just take it with you. Step 10. If the total area of the two ICIPs outside the intersection represents less than 10% of the total area of the largest of the two ICIPs, then you have successfully "eaten" the ice-cream cone via the certified DoD method, and the differences in targeting accuracy attributable to helmet presence are considered trivial. Step 11. If the two ICIPs do not intersect at all, forget the experiment, and instead, accept an honorary membership in the DoD. Don't worry about a membership number: you couldn't use one of 'em anyway. :-) Chuck Rogers car377@torreys.att.com