And in a former life, I used to amateur race production sportbikes (a 1997 GSX-R750, to be exact). Metal caps with gaskets were indeed required and part of the tech inspection. I didn't often near 150mph as the tracks I raced on didn't have long enough straights... Thunderhill was the fastest, probably mid-140's every lap. Sears Point (now Infineon) was a bit slower, but a lot hairier, and almost more fun in a sadistic sort of way (those of you who have turned a wheel in angst there know what I mean.)
I've found cracked plastic caps on some of my vehicles in the past. I try to use only metal caps with gaskets on all my cars (and bike). Be careful, some are better than others - some metal caps have no gaskets, or poor gaskets. Plastic caps are useless except to keep dirt out of the Schrader. =) +dm > ------------------------------ > Date: Thu, 15 Dec 2005 20:32:47 -0500 > From: Mitch Haley <[EMAIL PROTECTED]> > Subject: Re: [MBZ] Filling tires with nitrogen>> > > > I used to work for a guy who raced production and showroom stock motorcycles. > Tech inspection required metal valve caps with gaskets inside. Unless you've > got caps like that, The Schrader valve is the only thing holding the air in. > (on the motorcycles, the valve is precisely radial to the axle, and the valves > can open from centripetal force at 150mph, so the caps are needed) >
