Round tires?

ColoCardinal · #1 03-22-2012, 06:58 AM

Does anyone know of another manufacturer of the nose gear tire for the two place RVs? The tire supplied with my kit is so out of round (1/4"?) that I think it's unuseable. Is a larger sized tire / wheel combination an option which could give me more options?

Wayne Gillispie · #2 03-22-2012, 07:47 AM

I thought the same. Mine were all 1/4-3/8". Fine after 40 but I will be replacing soon.

Guy Prevost · #3 03-22-2012, 07:56 AM

Mostly because of the poor quality tubes we have to use, I eventually switched to a Beringer wheel with a tubeless tire. I believe it to be a significant step up in quality of the wheel, bearings, and tire.

PerfTech · #4 03-22-2012, 09:12 AM

...In the course of doing our upgrade bearing mod for the nose wheels I have had over 100 of these mounted and spinning on our balancer. So far I believe I may have seen 2 or 3 that were what would be considered usable for run-out. One (the best) was a garden tractor tire from northern hydraulics and the other must have been a mistake and they: got one right. The balance on all of them were terrible as well, averaging 2 oz on most (a huge amount for these small tires) We are in the process of building a truing machine for these small tires and should have it up and running in a few days. I trued and precision balanced all three wheels on my 9 and can't believe the difference. All the noise, shaking and vibrations are gone, it feels like a new or different airplane. Anyone interested or wanting more information please contact us. Regards all, Allan...

pkill · #5 03-22-2012, 09:53 AM

The Nose and the Mains were all dang near perfect right out of the box, spun true, no balance necessary. But a few months mounted, with the weight of the Plane on, and they all have a serious flat spot. I’ve been turning them occasionally during the build and I’m thinking they will round out again once we start flying ?

pk

Rupester · #6 03-22-2012, 10:22 AM

I called Desser the other day and asked if they had a higher quality tube for Vans nosewheels. They said that in the 11x4.00-5 size there really is no "aircraft grade" tube that they know of. I took that to mean the ones we have are "garden tractor grade". It sounds above that even garden tractor TIRES are better than the Chinese ones we get.

ColoCardinal · #7 03-22-2012, 10:07 PM

Allen, how do you true a tire. Can you actually make the carcass round? Im still curious as to whether there is a larger size tire or tire and wheel combo that we could use. I have your gear mod installed. Not the easiest install but the mod itself is genious.
Thanks for everyones input. At least i now know i have some good company!

Walt · #8 03-23-2012, 06:52 AM

I switched to the Beringer for the same reason, to get rid of the cheap tube. The new 8 ply tire that Desser sells is not to bad though and seems adequite to do the job. The way I've seen tires trued in the past was to basically trim the rubber off like a big lathe would do, not sure that's really necessary for the relatively low speeds the tire sees.

gasman · #9 03-23-2012, 12:26 PM

Quote:

Originally Posted by Walt

I switched to the Beringer for the same reason, to get rid of the cheap tube. The new 8 ply tire that Desser sells is not to bad though and seems adequite to do the job. The way I've seen tires trued in the past was to basically trim the rubber off like a big lathe would do, not sure that's really necessary for the relatively low speeds the tire sees.

This happens every time you land on hard surface. As long as it's in a different spot on the tire each time then no problem.

LarryT · #10 03-24-2012, 01:13 PM

It is more than just being "round." At the tire manufacturing plant all passenger car tires are actually mounted on special two piece wheels and run against a large drum. the center to center distance is held constant. there is the nominal load that varies slightly as the tire rotates. The variation is the "radial first harmonic force variation" (Imagine the tire as a series of radial spokes that are springs with slightly different spring rates and you get the idea). the colored wax dots on the sidewall of the tire indicate how well it was made. OEM car manufacturers get the best tires, the rest are "downstreamed" to tire stores in the following priority: Company tire stores; independent tire stores; gas stations. There is no such thing as a "cosmetic" blem. If the tire is labeled blem it is square.

the spring rate variation occurs because of tolerances in the tire building process.

One car company i worked for had a specification of 12 lbs. maximum radial force variation. Not much for a tire designed to carry 1000 Lbs @ 1g. the gushier (engineering term :-)) the suspension bushings are, the more sensitive the vehicle is to vibration input from tires.

I suspect the Chinese hand-building the nose wheel tires have never heard of "radial first harmonic force variation."

Larry Tompkins
N544WB -6A
W52 Battle Ground, WA