Replacement tires and wheels are 15", not 14"

[jd50i]

My 2014 21RR has ST205/75D 14 tires. I ordered a replacement set with wheels but I received 15". Besides checking for fitment taking into account suspension travel, is there anything else I should look at? I have written Forest River but haven't received a reply yet.

[jd50i]

On a thread for a 27RR that had swapped to 15" wheels, they had rubbing in a turn so something else I will have to look out for. I would send them back but have a trip planned next week.

[Bama Rambler]

Does your RV have torsion or spring hung axles?

If it has spring hung you could just change the shackles out for longer ones if top clearance is a problem. You can add a lift kit to the torsion axles also, it's just a little more work.

[SeaDog]

check the clearance between the tires on my rig if I went to 15" my clearance would be way to close.

[jd50i]

Originally Posted by Bama Rambler

Does your RV have torsion or spring hung axles?

If it has spring hung you could just change the shackles out for longer ones if top clearance is a problem. You can add a lift kit to the torsion axles also, it's just a little more work.

I believe they are spring since it has a equaflex added.
If they won't fit, I'll send them back. I'm not spending money modifying the suspension. I just wanted to know what to look at for proper clearance.

[Murbella7]

Originally Posted by jd50i

My 2014 21RR has ST205/75D 14 tires. I ordered a replacement set with wheels but I received 15". Besides checking for fitment taking into account suspension travel, is there anything else I should look at? I have written Forest River but haven't received a reply yet.

If the 15" wheels fit without rubbing and there is enough clearance for road bounce, keep them. They will be more robust than the 14" wheels.

[jd50i]

I haven't put them on yet but width measured very close to the same and circumference was about 1" more on the 15" tires. I would have thought it would be more since the ratios are the same 205/75. I'll get them on this weekend and find out for sure.
The other thread I read talked about 15" aluminum wheels rubbed. I bet the wheels were wider.

[jd50i]

Not circumference, diameter.

[Murbella7]

Originally Posted by jd50i

I haven't put them on yet but width measured very close to the same and circumference was about 1" more on the 15" tires. I would have thought it would be more since the ratios are the same 205/75. I'll get them on this weekend and find out for sure.
The other thread I read talked about 15" aluminum wheels rubbed. I bet the wheels were wider.

Tires rubbing on the inside can be caused by one of three things...

1: tire profile. The tire is too wide for the rim (this is a typical 'upgrade' when you are trying to look 'cool', gives the wheel a deeper look, which looks good in chrome).
2: The center of the rim is too far to the road side and hence the wheel rim itself hangs over the axle more to the inside than over the nut on the outside. This is the reverse of a typical cosmetic upgrade deep-dish rim as above and means that the rim is most likely incorrect for the setup.
3: Stuff badly mounted under the unit so that it/they connect with the rubber. This will mean remounting said 'stuff' - spring hangers, shocks, brake cable hangers, etc.

If you 'upgrade' from a smaller rim to a larger one (as I did - from 15" to 16") you can still use the same tire profile and hence still have the same clearances. The difference will be in tire diameter. Going up in size will decrease clearances by just half and inch, from the tire cap. Meaning you will lose just half an inch clearance from tire to body and raise the unit up off the road surface by the same amount. What you will gain is the ability to choose a more robust and hence longer living and safer, range of tire - LT for example.

[jd50i]

I'll try them on tomorrow but right now it looks like there won't be a problem, seems to be plenty of wheel well available all over.


I got a reply back from Forest River, they said;

"Forest river can only give recommendations on products your unit was manufactured with. If your unit came with 205/75D 14 tires then I can only recommend that's what you put back on it. You can reach out to a local Forest River dealer, RV repair shop or tire shop who can answer your questions on if the size you received can be used."

[Murbella7]

Originally Posted by jd50i

I'll try them on tomorrow but right now it looks like there won't be a problem, seems to be plenty of wheel well available all over.


I got a reply back from Forest River, they said;

"Forest river can only give recommendations on products your unit was manufactured with. If your unit came with 205/75D 14 tires then I can only recommend that's what you put back on it. You can reach out to a local Forest River dealer, RV repair shop or tire shop who can answer your questions on if the size you received can be used."

All I can say about FR's recommendations is that's OK for an unloaded unit. From experience, you should seriously consider upgrading your wheels to a larger rim size and a more robust tire. Having a tire explode while motoring down the road is no fun AND it will cost heaps to remedy because the collateral damage will be far more extensive and expensive than just a tire replacement.

[jd50i]

Originally Posted by Murbella7

All I can say about FR's recommendations is that's OK for an unloaded unit. From experience, you should seriously consider upgrading your wheels to a larger rim size and a more robust tire. Having a tire explode while motoring down the road is no fun AND it will cost heaps to remedy because the collateral damage will be far more extensive and expensive than just a tire replacement.

I got the new 15" wheels on, not fitment problems I could see.
What are you considering a "robust" tire? Brand? size?


These are the ones I bought, except I received 15".

[jd50i]

looks like the link didn't show on my last post.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I have also noticed another problem, they sent me radials. Anything I need to look for when switching from bias to radials?

[Bama Rambler]

As long as you're switching all of them out, there should be no issue.

[jd50i]

Originally Posted by Bama Rambler

As long as you're switching all of them out, there should be no issue.

Yep, all being changed out. I did mix and match on a car in the early 80's, it rode and handled funny.

[jd50i]

I just put 2000 miles on the 15" with no problems so if you have a 21RR it seems you can switch easily to 15" wheels and tires as long as the ratio is the same.

[Murbella7]

Originally Posted by jd50i

I got the new 15" wheels on, not fitment problems I could see.
What are you considering a "robust" tire? Brand? size?


These are the ones I bought, except I received 15".

Go with LT's. Designed for a bit of load, which is what you will have.