Joe, My J3 Cub and also my Piper PA17 Vagabond may have the same wheel and tire type as you describe and I go by the Book which says 12-15 PSI for these balloon tires. I do have a low pressure type gauge that is commonly available in auto stores but I have always found it very unreliable for the testing of tire pressure as it is difficult to get an accurate reading. I try to keep my tires on the soft side a bit, however if too soft then these old wheels will slip the tire and tube enough causing the valve stem to break off causing a ground loop should too much braking be applied. I have found that it is better to keep pressure somewhat higher such that when I push down by hand on the tire top that I can feel some give.. If you have to go on the softer side then stay off the brakes. Applying even a bit too much braking can rip the valve stems off. Not a good way to start you day. After having that experience last year, I now keep the tire pressure a little higher and a complete spare wheel ready to mount just in case. Those 800 4 tubes are very expensive as are the tires. Many people have switched to more modern wheels and tires types.
Ron Hynes , Alberta , Western Canada --- On Thu, 9/24/09, joe_boucher <[email protected]> wrote: From: joe_boucher <[email protected]> Subject: [ercoupe-tech] Another Tire Pressure Question To: [email protected] Received: Thursday, September 24, 2009, 12:15 PM Hi All, I've read the archives about tire pressure and shimmy, and found that my nose tire was seriously over-inflated after my last annual, probably accounting for the sudden shimmy after it came out of the shop. I've reduced nose pressure to the recommended 17 psi and it has helped a lot. My question regards the mains. My Coupe is a 415C, manufacture date 12/6/1945. I understand that above a certain serial number the mains are 6.xx-X, but on my bird (s/n 164) the mains are 8.00-4. Easy question: any ideas on the recommended tire pressure for these larger tires? I think I'm actually getting shimmy from one of the mains now, as the plane tends to skitter across the runway. Again, I suspect overinflation of the mains during annual, and I'm reluctant to just bring them down to 17 psi to match the nose. Any advice would be greatly appreciated. Thanks, Joe Boucher N86991 s/n 164 __________________________________________________________________ Looking for the perfect gift? Give the gift of Flickr! http://www.flickr.com/gift/
