8a main wheel shimmy

[ERJDriver]

Landed the other day, nice smooth touchdown, rolling through 50kts or so the mains started shimmy-ing. Neighbor that saw said it looked like the right main was moving 8 inches back and forth 😳 onlything that has changed is i aired them up to about 45 last week.

Ideas?

[David Paule]

Drop the pressure down to where it was?

Dave

[gasman]

You can reduce the pressure and risk tube damage. Try 40#. As you go lower, you risk tube damage., or you can brake through it. At first sign of shimmy, apply brakes for a few seconds then release. You will find the zone of needed brake to avoid the shimmy.

This will buy you time to resolve the issue.

[ERJDriver]

Originally Posted by gasman

You can reduce the pressure and risk tube damage. Try 40#. As you go lower, you risk tube damage., or you can brake through it. At first sign of shimmy, apply brakes for a few seconds then release. You will find the zone of needed brake to avoid the shimmy.

This will buy you time to resolve the issue.

Yeah tried to get on them and get it slowed down, basically shimmied through 20kts

[Taltruda]

Some people have had luck with balancing the wheels, seems that an out of balance wheel can help “excite” the shimmy. Also others have added leas shot mixed with epoxy to the front inside the wheel pants, seems to shift the CG of the pant forward and may help. Other than that, as you’ve discovered, adding too much air can cause a shimmy. I don’t feel the risk of damage to a tube is a problem down to 30psi with proper landing techniques, don’t side load the landing my landing sideways, proper cross wind technique, ect.. I start at 40psi and if they still shimmy, try 35, then 32..

[Tim Fitzpatrick]

Sent my main tires in to Anti-splat, quick turn around and great service. Also fiberglassed wooden brace on main legs, psi at 36ish. My shimmy around 25 knots of ground speed is gone. Just my experience, good luck hope you find a solution.

[jrs14855]

What does anti splat do to the tires?

[N82VM]

They will balance and true the tires. They also can machine the wheels and replace the old bearings with sealed bearings. Supposed to be smoother.