My Turn for a tire blow out

[Ozz]

[Exnavydiver]

Wschep, I got the info on the 17.5 upgrade after the fall rally. I posted it on here somewhere. The article was a quote from the Escapees forum. A couple of guys there dis a long research project on this. The jist of it was that with a 16 inch rim and G614 tires you have a load limit of 3750 lbs on each tire at 110 psi. On a 17.5 rim with Goodyear G114 tires you have 4750 lbs at 125 psi. Rather than working at almost the max rating of the G614s if you use the G114s on the 17.5 rims you are working at only the top 80% of the load range. This gives you some wiggle room if the tire is over stressed. At present we are at the very top limit of our Marathons all the time and if we whack a road hazard we have no room for safety. I would much prefer to have a bit more latitude in limits.

update:here is the link to my original post on this issue. Within that post is another link to the original article.

[kingdaddy]

Wouldn't the G614 tires be more than adequate though? At that rating the 4 tires are capable of 15,000 lbs. So even with a 16k trailer (assuming some of the bigger Montys weigh that much fully loaded) wouldn't the tires only be carrying about 12-13k of that weight?

[Wschep]

I know the tire issue has been debated forever. I am wondering if some of our problems are coming from the amount of skewing that our tires go through when we take tight turns. When I look at a hot tar surface with my tires sliding across at almost a 90 degree angle, it would seem we are almost ripping the tire tread off the tire. When you have a weak tire to begin with, perhaps now its just a tread separation blow out waiting to happen.

Anyways, I went with 17.5 inch wheels, and Sumitomo 215/75/17.5 inch tires. These are 16 ply and am hoping can withstand much more than my China bombs.

[8.1al]

Wschep,
According to a rep from Goodyear that I talked with you are right, that side loading literally rips the tread loose from the casing

[kingdaddy]

It's unavoidable I suppose based on the design and physics of tandem axles. Maybe some really smart person can design a relatively simple and inexpensive steering linkage/mechanism to help mitigate the effect.
Wschep-sounds like some seriously heavy duty running gear! I'm guessing your blowout problems are behind you...

[larnmar]

Called Jennifer today,she said they had retested the rims and will not re certify them

[Ozz]

quote:Originally posted by larnmar

Called Jennifer today,she said they had retested the rims and will not re certify them

I now wonder if they made a mistake sending out the stickers to the rest of us.
I also wonder if the Lawyers intervened and stopped the re-certification because of legal reasons, or the engineers stopped because of structural reasons...
Man, it's always something!

[8e3k0]

I can understand now why they would not recertify after a number of members have encountered rim cracking!! That tells us the quality of those rims. It is another product I am contiually watching. Would like to get away from spokes and go the the aluminum style with 8 or 10 holes (a better structured rim). If I went to 17.5 wheels I would then change our the axles to 8000 lb and hydraulic disc brakes. At least the axles would be in the 75 to 85 % load rating and not 100% especially when cornering at 65 mph. I sometimes wish I had no mechanical background! LOL

[DarMar]

quote:Originally posted by kingdaddy

Wouldn't the G614 tires be more than adequate though? At that rating the 4 tires are capable of 15,000 lbs. So even with a 16k trailer (assuming some of the bigger Montys weigh that much fully loaded) wouldn't the tires only be carrying about 12-13k of that weight?

I definitely agree with you on this one. If you have a trailer GVWR such as ours which is 15560 lbs. and you load it heavy to even 15000 lbs. you ARE going to have a pin weight of at least 3000 lbs. That leaves only 12,000 to 12,560 lbs. left for the tires to carry. Even with our lop sided weights, 880 lbs. more on driver's side, we still have lots of wiggle room with the g614's.