I've read through a few older threads that talked about rolling resistance, but I'm wondering if anyone here as done significant research or is aware of any research regarding the change in takeoff distance relative to tire size/pressure?

I ask because when I had the stock tires on my 182, pushing it into the hangar was a breeze. With the 8.00's at 20PSI I can barely push it up the very slight incline to my hangar, and I'm no small dude. Loaded to gross, the tires are looking pretty flattened at 20PSI, and I'm considering leaving the mains at 25PSI instead, and leaving the nose at 20... if nothing else just to at least avoid a hernia.

How much does this increase in rolling resistance affect the aircraft in the real world?

I run 25psi on my 182E with 850x6 on the mains, rolls pretty good.

That depends on the surface your on. On 8:50s I can push it really easy on pavement, much easier than on the 31s. Put it on the beach or soft gravel and your not going to budge it on 8:50s by hand but can easily roll it on the 31s.

Set your plane up for the best performance for your mission and what you like to do.

akavidflyer wrote:That depends on the surface your on. On 8:50s I can push it really easy on pavement, much easier than on the 31s. Put it on the beach or soft gravel and your not going to budge it on 8:50s by hand but can easily roll it on the 31s.

Set your plane up for the best performance for your mission and what you like to do.

What he said. And if you have an incline into your hangar, do your back a favor and install a winch.

MTV

On smooth hard surfaces, tire size has a very weak role in rolling resitance. Rolling resistance is dominated by tire flex in this case, so it is driven by construction and pressure. The lower the pressure, the more the flex, and rolling resistance rises slightly.

On uneven and soft surfaces, tire diameter can can become important for geometric reasons, and lower pressure can actually reduce rolling resistance as geometry outweighs tire flex.

I find the winter temperatures have the largest impact on rolling resistance in and out of the hanger....tires get much stiffer.

akavidflyer wrote:That depends on the surface your on. On 8:50s I can push it really easy on pavement, much easier than on the 31s. Put it on the beach or soft gravel and your not going to budge it on 8:50s by hand but can easily roll it on the 31s.

Set your plane up for the best performance for your mission and what you like to do.

Excellent point, hadn't looked at it that way.

Thanks guys

So yes I have done that type of research with 31 inch bushwheels 3 vs 4lb can cost you 15-25 ft in takeoff distance depending on load. as far as a 64 year old pushing into a hanger 8 psi is MUCH BETTER than 4 psi!!! I carry a 12vt air compressor in the plane for off field work, go in low come out high.
DENNY

For whatever it's worth, I aired up to 25 psi last night, and pushing the plane back into the hangar was much better. I'm leaving them at 25 psi