different tire sizes

[Bobgaudette]

I bought a used 2016 thor windsport 34j 2 years ago and now need to put new tires on it. the tires on it are all 245 70 19.5's. every spec sheet i pull up on the rv says it comes with 235 80 22.5's. it didnt have enough time or miles on it to require new tires, so what is up with this?

[16ACE27]

245 70 19.5 seems to be the standard F53 tire for the lighter GVWR chassis and what we have on our ACE.

But you have the 22K lbs chassis which should have the 22.5" tires/wheels on it. You should have a sticker near the driver's seat that list tire/wheel sizes and inflation requirements.

Hard to believe somebody swapped all 6 tires/wheels out.

[Bobgaudette]

my thought exactly about swapping out all 6 tires. Thanks for the info on the sticker. Im familiar with the sticker and when the RV comes back I will see what the sticker says. Sorry for my ignorance but did they have to change all 6 rims to put 19.5 instead of the 22.5?

[Skip500]

Yes!

[EA37TS]

Do a VIN search to verify the chassis configuration.

On the 22k chassis the 19.5 tires were an option. What is on the motor home is dependent on the chassis delivered.

Based on memory Hurricanes and Windsports were all 19.5 while Challenger and Miramar were all 22.5.

[Bobgaudette]

the vin search said it was a 19-25k chassis, but nothing about the rim size. I did however find a picture on my phone that had part of the label near the drivers seat that i can clearly read 245/70r19.5, so i guess that solves that! Thanks for all you guys help, your worth a million, keep up the good work.

[Sappy2]

PM me the last 8 of your VIN and I will look up that unit's build data.

[lwmcguir]

Originally Posted by Bobgaudette

I bought a used 2016 thor windsport 34j 2 years ago and now need to put new tires on it. the tires on it are all 245 70 19.5's. every spec sheet i pull up on the rv says it comes with 235 80 22.5's. it didnt have enough time or miles on it to require new tires, so what is up with this?

19.5 tires come with many choices in ply and size. What would you gain by switching wheels and maybe having to change the rear studs as well.

Are your current wheels aluminum or steel?

I have had a bunch of heavy duty pickups running 19.5's and never had any issues hauling heavier loads than a motor home

Just curious as to your thoughts on perhaps changing

[EA37TS]

Originally Posted by lwmcguir

19.5 tires come with many choices in ply and size. What would you gain by switching wheels and maybe having to change the rear studs as well.

Are your current wheels aluminum or steel?

I have had a bunch of heavy duty pickups running 19.5's and never had any issues hauling heavier loads than a motor home

Just curious as to your thoughts on perhaps changing

The OP never said he was going to change. They were uncertain about what came stock vs what was actually on the coach.

Re-read the initial post.

[Jimbo56]

On another thread on this forum there is a tire inflation guide that will allow you to carry the weight of your RV with proper psi inflation. Have you weighed your coach?

[Beau388]

Originally Posted by Bobgaudette

I bought a used 2016 thor windsport 34j 2 years ago and now need to put new tires on it. the tires on it are all 245 70 19.5's. every spec sheet i pull up on the rv says it comes with 235 80 22.5's. it didnt have enough time or miles on it to require new tires, so what is up with this?

In 2016 model year, standard rims were 19.5x6.75 inch steel rims for all plant 750 coaches (Freedom Traveler, ACE, Hurricane, Windsport). Optional from Ford (Detroit Chassis) was the 22.5x7.00 aluminum rims. Starting in 2021 with the V-8 chassis, plant 750 began specifying the optional 22.5x7 inch aluminum rims on all 20,500 lb and higher chassis. This was done for marketing, as the intent was to upgrade the entire line to better suit the dealers request for a more modern looking coach and allow the Plant 750 coaches to be able to better compete with the Tiffin and Jayco's gas coaches. The rim and tire size change adds about $3,000 to each stripped chassis cost.

[jadatis]

Lets check if the 19" have enaugh maxload to cover the GAWR . If so , yust get new tires on the 19" rimms.

For that you need :
1 GAWR's
2 maxload of tires or loadindex
3 speedcode would be nice
2 and 3 can be found on sidewall.

[Beau388]

Originally Posted by jadatis

Lets check if the 19" have enaugh maxload to cover the GAWR . If so , yust get new tires on the 19" rimms.

For that you need :
1 GAWR's 22,000 lbs
2 maxload of tires or loadindex 4540/4410 lbs (133 load rating)
3 speedcode would be nice 75 mph
2 and 3 can be found on sidewall.

The specs are for Goodyear G670 RV tire in the 245/70-19.5 size which was the standard tire on all 2016 Plant750 coaches
For six tires the weight rating would be 26,900 lbs with 17,900 lbs on the rear axle. Max axle weights are listed a 8,000 lbs front and 15,000 lbs rear

[TLeenhouts]

Be very careful when replacing the tires on your RV. I have a Windsport 32R and the tires has lots of tread but could not be balanced due to being so far out of round. I bought Kellys for the front and one had to be thrown away after 4000 miles for being 1.9 inches out of round. Bought 4 Falkens for the rear and they are fine. Replaced the one in the front with a Falken.
Make sure you check the load range and the SPEED range. One dealer tried to sell me tires withe a B speed rating which is 31 miles per hour. He said they do that all the time. My load range was G but I went with H rating (16 ply) and speed rating of M which is 81 mph.
No more shake at 62 mph.

[Jimbo56]

Originally Posted by TLeenhouts

Be very careful when replacing the tires on your RV. I have a Windsport 32R and the tires has lots of tread but could not be balanced due to being so far out of round. I bought Kellys for the front and one had to be thrown away after 4000 miles for being 1.9 inches out of round. Bought 4 Falkens for the rear and they are fine. Replaced the one in the front with a Falken.
Make sure you check the load range and the SPEED range. One dealer tried to sell me tires withe a B speed rating which is 31 miles per hour. He said they do that all the time. My load range was G but I went with H rating (16 ply) and speed rating of M which is 81 mph.
No more shake at 62 mph.

1.9 inches out of round? No way!

You can balance an out of round tire.

[TLeenhouts]

Originally Posted by Jimbo56

1.9 inches out of round? No way!

You can balance an out of round tire.

You can balance it but you can't take the shake out of it. Believe me, I've tried numerous times. One of the tires I replaced last year was out of round by 2 inches as well. The tire guy I use now said the spec. is less than .9 inches.

[Jimbo56]

Originally Posted by TLeenhouts

You can balance it but you can't take the shake out of it. Believe me, I've tried numerous times. One of the tires I replaced last year was out of round by 2 inches as well. The tire guy I use now said the spec. is less than .9 inches.

If that’s the case now, manufacturer’s standards are much different than in the 70’s and 80’ s when I was with BFGoodrich. With a radial runout gauge, if it was more than a half inch, it came off the vehicle. Off the wheel. Then the wheel itself was checked. A lot of times the stamped steel wheels were out. The cast aluminum composite wheels seemed to be made to tighter specs.

[lwmcguir]

Originally Posted by Jimbo56

If that’s the case now, manufacturer’s standards are much different than in the 70’s and 80’ s when I was with BFGoodrich. With a radial runout gauge, if it was more than a half inch, it came off the vehicle. Off the wheel. Then the wheel itself was checked. A lot of times the stamped steel wheels were out. The cast aluminum composite wheels seemed to be made to tighter specs.

All the vehicles I ran over the years that had out of round tires were taken in to the shop and returned to the vendor for credit

If being mounted at a reputable tire shop they would typically catch them and never mount them.

Even .9 is way to much for any steer tire or a passenger tire