I have then inflated to 50psi as it says on the side wall. But they look a little soft or under inflated by appearance. Is this normal since they are radial tires ? I am used to bias ply which I had before and they looked very hard and not under inflated at all with 50psi.

Rebs, I have the same size as yours, 205/75-14, and even at 50psi, mine look low too. But, I've checked them with multiple gauges, so I'm confident the pressure is correct.
HRG

I haven't had my boat out yet since the new tires. How do they run down the road ? It looks like they are soft and may have more sway to them than the bias ply. Has anyone found this to be true or not ?

I have had radials on the last 2 trailers and they have been just fine.

Other than the fact that mine are near bald. I love'um

I put them on the list of things to buy for the boat and its looking like its gonna cost around $230 for the whole sha'bang.

It's normal. Compared to bias ply, radial trailer tires always look a bit low on air. It was the same thing back when cars changed from standard bias-ply to radial tires- everybody would tell you your tires were low.

The 215R75-14 Marathons on my trailer look low on air, but are at 50 psi and carry the 3100 lb trailer just fine. There is a bit more flex in the tire sidewalls, might cushion the ride for the trailer.

Rebs,
Look at your boat/trailer specs. They may recommend a psi less than the max rating as listed on the tire.
http://www.goodyear.com/rv/pdf/rv_inflation.pdf

Take care,

Thank you for the replies, I see I am good at 50 psi

Thank you for the replies, I see I am good at 50 psi


Rebs,

This is from a prior post.

http://www.goodyear.com/rv/pdf/marathon_gen_info_032806.pdf


I inflate mine to 56-58 psi based on this ... staying below 60 psi but hedging my bet so I am over 50 psi.

Rebs,

This is from a prior post.

http://www.goodyear.com/rv/pdf/marathon_gen_info_032806.pdf


I inflate mine to 56-58 psi based on this ... staying below 60 psi but hedging my bet so I am over 50 psi.

I believe you are right, I seldom trailer over 65 mph, only in other states where the speed limit is higher. I am going to seriously consider mine at 55-56 to be in the middle ground for around home and short trips 65 and under and bump up to 60 psi for out of state trips.
Thanks for the heads up, I appreciate it.

I thought I was the only one seeing the tires look a little on air. Thanks for the explanation on the bias ply vs. radial appearance.

I should know better, my father built tires for 25 years.

Duran

Rebs,

This is from a prior post.

http://www.goodyear.com/rv/pdf/marathon_gen_info_032806.pdf


I inflate mine to 56-58 psi based on this ... staying below 60 psi but hedging my bet so I am over 50 psi.

I also inflate mine to 10 PSI above per the link. I figure that even if I don't go above 65 that is an extra measure of safety. Better over than under in my opinion.