Tire Pressure

[cleach]

Hey Guys,

I have a M4 2-seater (gross weight 2300 pounds). I recently changed from 7.00x6 to 8.50x6 on the mains. They seem to be a lot more susceptible to bouncing. Goodyear recommends 30 psi, Maule recommends 24 psi, and I have seen some bloggers recommending as low as 18 psi. I am currently running 22 psi. Is there a better pressure? What should the pressure be for paved surface landings versus dirt or grass?

Comments appreciated.

[Kirk]

Really anything in the 18-26 range works fine. Lower pressure in the 18-20 range helps a bit on choppy surfaces like rocks or pasture that has had cattle on it.
Watch your sidewall clearance of tire to brake assembly at lower pressures. My old tires would rub the brake housing slightly at 18 lbs Now with Goodyears there is more clearance.

Kirk

[Victor Gennaro]

21 lbs with my m7 235 spring gear seems like the sweet spot for pavement and good grass surfaces. Although it is attractive to blame my episodic "bouncing" on the tire pressure, it is more likely related to my touchdown speed and poor technique.

[TomD]

I run 22 psi or so when on hard surfaces, and drop a couple of pounds when on soft surfaces.

[cleach]

Thanks for the info. I do find that I need to really keep the touchdown speed low on those 8.50s or I will bounce.

[TomD]

I do find that I need to really keep the touchdown speed low on those 8.50s or I will bounce.

That's my story too and I am sticking with it.

TD

[iceman]

12 lbs on pavement no lower than 9 on dirt and rock... oh I'm sorry you have those itty bitty tires.....lol

[Flyhound]

Low touchdown forward speed and low sink rate are both important. I had trouble early on because I was slowing down too much and getting sink rates that were too high as a result. Timing the re-application of power or an aggressive flare to offset the higher sink rate is challenging and resulted in some pretty spectacular bounces. So, watch both forward, and vertical speed and you'll be golden.