We run 23 to 25 psi to control any shimmy tendencies. Lower pressures seem to shimmy less at the expense of tire life. Much under 20 and I start worrying about where we'll have the rubber spin on the rim, but we haven't had it happen even at very low pressures of around 15. Harder to push in the hangar below 20 and I'm sure the takeoff roll is longer...
The original builder of my RV-3 listed 29psi as the desired tire pressure for my 3. I?ve always just used his recommendation. My plane is on the heavy side so maybe that?s why I?m at a bit higher psi.
__________________ Rod Woodard
Brighton, Colorado (CO12)
RV-3 IO-320
Anything over 26 in ours gives us noticeable gear leg shimmy - and that is WITH wooden dampers installed. Airplane handles fine at that pressure, and we’ve run through two sets of tires in 750 hours, so I call wear acceptable.
__________________ Paul F. Dye Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34) http://Ironflight.com
I used to run ~25 psi in my -3, but now run closer to 50 psi. I've never had shimmy throughout that range. Not only is the plane easier to roll around there's no chance of slipping a tire on the rim. When we do formation ground maneuvers we often spin on one of the mains.
At 23psi, no shimmy. At 26 psi and over lots of shimmy on the left leg at the end of the roll. I found this out by letting the tyres gradually deflate. No science!
Tire pressure
Hybrid Mode
