Tire blowout!!

[92landyacht]

No need to find a wheel. The wheel that I had was not damaged enough to warrant replacement. I know have 8 new tires mounted and ready for the road.

[Suspenderguy]

Hello all. I'm looking to replace 20 plus yr. old Goodyear unisteels on a 79. They are the 8R 19.5. I have a quote for Hercules 14 ply Stronguard Regional All Purpose tires in a 225/70R19.5. In the forums here I get the impression the size is ok but the speedo might be a little off. My question is has anyone used this particular tire and what is your opinion of them . Thanks for any info.

To clarify it's a 28 ft "79" AS motorhome.

[CapriRacer]

Originally Posted by Suspenderguy

Hello all. I'm looking to replace 20 plus yr. old Goodyear unisteels on a 79. They are the 8R 19.5. I have a quote for Hercules 14 ply Stronguard Regional All Purpose tires in a 225/70R19.5. In the forums here I get the impression the size is ok but the speedo might be a little off. My question is has anyone used this particular tire and what is your opinion of them . Thanks for any info.

To clarify it's a 28 ft "79" AS motorhome.

Here's the math:

If you start with 8R19.5's, they are supposed to be 8.0" wide on a 6.00 rim, with an overall diameter of 33.8", a minimum dual spacing of 9.1", and a load carrying capacity of 3525# at 110 psi for a Load Range F.

A 225/70R19.5 is supposed to be 8.9" wide on a 6.75" rim, with an overall diameter of 31.9", a minimum dual spacing of 10.0", and a load carrying capacity of 3640# at 95 psi for a Load Range F.

Assuming for the moment that you have 6.00 wide rims to start with, the 225/70R19.5 will be about 8.5" wide on that 6.00" rim. Since it is common for chassis manufacturers to specify minimum dual spacing rims, the net effect is that there will be a loss of about 1/2" space between the duals. I urge caution in this area.

Also, the diameter change results in 6% change - which means the speedometer will read 60 mph when it is going 57 mph.

And lastly the load. In order to carry the same load the 8R19.5 does at 110 psi, the 225/70R19.5 only needs 92 psi.

So the real danger areas are the rim width (minimum 6.00" for a 225/70R19.5) and the dual spacing (9.6" for the 225/70R19.5 on a 6.00” rim)

[Suspenderguy]

Thank you CapriRacer. I tend to agree with you . I think the original size is what the motorhome and wheels were engineered for and so I'm sticking with that . I have seen a lot of posts indicating quite a few have switched to the 225/70R19.5 and haven't seen any negative outcome reports. The unit I'm buying is about 70 miles north of me on I5 . I'm reluctant to drive it home on the current tires. Lots of tread but cracks in the grooves . I'm looking at the Dynatrac due to price and availability. Do you see any ride advantage in shelling out the extra 150 or so per tire just on the fronts for Michelin's or Goodyears and put the Dynatracs in the rear? Thanks very much for the input . I'll be looking at your site. Here's the AS I'm purchasing . https://www.facebook.com/marketplace...ssenger_banner

[92landyacht]

The Samson 8R19.5's have serviced me quite nicely over the years. I would not spend the boat load of money on Michelin or Goodyear's. Most tires are made overseas now anyway. All are DOT certified and trucking companies tend to use Samson or other "off brand" companies more today. They have a very good history on MH's. When you think about it, most motorhome tires are replaced due to age rather than wear.

[Suspenderguy]

I just went and saw a mechanic friend of mine . I didn't realize he was a tire dealer . He got me 6 Hankooks for 1600.00 . He's also had numerous motorhomes over the years and says I won't be disappointed. 8R19.5's all around . On to the next challenge!!! Thank you guys for the feedback . I love this forum.

[Mike1997]

Hankooks are great and rated high as Michelens. I just replaced 6 Hankooks installed in 2016 and other than age, we only found 1 tire with slight cracks near the rim. It was the same tire I was adding air to often. Of course it only takes 1 bad tire to ruin your whole day!!!