Billboard tire pressures

[BMK]

I know I am duplicating a Thread that I just started over on the Kirkham site but...

I have billboards on a Kirkham and I was wondering if anyone has experimented with lower pressures..

I was just told that lower pressures give a softer wall and better ride..



Has anyone experimented with tire pressures. - front and rear pressures.

Thanks

Bernie

[crossram_426]

I run them on my Kirkham and the person Inpurchased them from told me 26lbs when hot?

[rub35]

I've been running 22psi cold. Seems to work well.

[dcdoug]

I run 28 in front and 26 in back. I find 28/27 front and 26/25 rear reduces the hunting these tires exhibit. Regardless of pressure, try 2psi more in the front and see if you like it.

[ACademic]

Reduced pressures will also enlarge the size of the flat spot that these tires tend to create after each drive. They always work themselves out after a couple miles, but the "whop, whop, whop" shake will be more pronounced when you run low 20's psi vs. mid/high 20's. My rule of thumb is above 25psi for purely the street and at/below 22 for any spirited driving.

[BMK]

Thanks guys.

The variations give me a good range.

The billboards currently are at 28 lbs. This was the auto set at the tire shop.

As the Cobra is quite light with the aluminum block I am prepared to experiment. Being out of town I will run the temperature up on the highways so will look at a hotter temp pressure - as a start point.

The difference in the pressures suggested makes me feel comfortable in reducing and experimenting.

I have a high quality pro tire pressure gauge and a compressor in the garage so have the option to play until I find the optimum for me and my driving style - erratic..

Thanks again. I will run the pressure on the garage wall and change over the next few weeks. Thanks again.

Bernie

[ACademic]

Bernie, another thing to think about. The billboards' thin bias ply construction doesn't necessarily hold air as well as a radial would. So don't be surprised if you started off the week at 26psi and one week later that same tire was at 25...or 24...or even 23. I've had bleed-off of a couple psi in a week's time depending on the weather.

[BMK]

ACademic

Thanks fir the feedback, I will keep an eye on that. I did notice there was a slight variation in pressure from wheel to wheel when I swapped them onto the Cobra - I have a set of Avons on new Vintage wheels as spares.

As I mentioned, I ave a very good quality gauge and compressor - ex my business where pressures are dead accurate. So will get them right with the gauge. The compressor and the lines, gauges etc are within easy reach for me to check each time I drive.

Thanks again for the help and recommendations.

Bernie