Community Forums

MEXICAN · 10-08-2010, 06:10 AM

hello guys, i was wondering if somebody can answer a question.
Can i run 16 inch wheels on my 94 seabreeze instead of 19.5?
The reason im interested in doing such a thing is because i go to Mexico often and the last time i had 2 blowouts, i had 1 spare but to find another 19.5 was almost imposible, in fact they had to ship it from the US, i know i can limp home on 5 wheels but rather not, besides the price a lot lower on 16s.
Has anybody done this before? pros, cons? where do you get the wheels?
Thanks,,,Lupe

Richard S. · 10-08-2010, 06:58 AM

Look for the tire certification label in your motorhome, it may have been manufactured with 16 inch wheels. Is it a Ford or Chevy.

MEXICAN · 10-08-2010, 10:45 AM

It is a chevy, I saw a ford the other day and it had 16s, I didn't know they made both chevy and ford versions, my tire specs say 19.5

Nick-B · 10-08-2010, 01:34 PM

The Chevy chassis used the 19.5 rims/tires at least back into the late 80's - or maybe always - so your Sea Breeze must be on a Chevy chassis.

The Ford F53 chassis all used 16" rims/tires through (I think) 1997.

Now, you say you want to change over and it sounds simple enough but I have read of folks who wanted to do just the opposite. Put the bigger 19.5 rims on the Ford chassis. The problem they run into is the center hole/bore of the rims is a different size. Won't fit.

I do not have first hand experience with this, it is just what I have read, so maybe someone who has actually tried it can offer more info.

SteveLevin · 10-09-2010, 10:53 AM

I was always under the impression that coaches with 19.5" wheels had bigger brakes (larger diameter rotors) than 16" -- which would mean that it'd be unlikely you could "downsize" to 16". First thing I would do is take a quick look at the rotor and caliper assembly and unless there's a LOT of space (around 2") between the caliper and the wheel, it's a non-starter.

The other thing is that you may not be able to put your weight on a 16" setup. Not having a 19.5" I don't know the wheel loading (although clearly, on more modern coaches, you can have something like 22,000 pounds total). With a 16" tire you will be at Load Range E (I think) and be limited weight limited to 11,000lbs. on the rear axle and 6,000lbs. on the front (at least, with all the tires I've found for 16". I've done some looking because my coach loaded as we travel weighs 10,800 pounds and I'd spend money for a larger margin if it was available (it wasn't)).

Steve

MEXICAN · 10-09-2010, 08:20 PM

Quote:

Originally Posted by SteveLevin

I was always under the impression that coaches with 19.5" wheels had bigger brakes (larger diameter rotors) than 16" -- which would mean that it'd be unlikely you could "downsize" to 16". First thing I would do is take a quick look at the rotor and caliper assembly and unless there's a LOT of space (around 2") between the caliper and the wheel, it's a non-starter.

Thanks for the info Steve, i wonder what the difference is between ford and chevy, i know for a fact that ford has 16s i saw one the other day, chevy has 19.5s and the rvs are identical, wonder what gives

Nick-B · 10-10-2010, 07:03 PM

Load rating for the LT235/85R16 tires is 3042 LBS at 80 PSI
This size is what most of us older Ford chassis guys run. There isn't much else to choose from for the high load 16's.
Load rating for the 225/70R19.5 tires is 3640 LBS at 95 PSI
Load rating for the 245/70R19.5 tires is 4080 LBS at 95 PSI
These are nuimber I pulled from the Michelin web site.

So it is true the 19.5" tires can carry more weight, however, the limiting factor will be what the axle is rated to handle.

MEXICAN, you don't say what length your Sea Breeze is or what the chassis specifications are. They made them 29', 31' and 33'. I don't know if the are specs online for National but Winnebago does have old specs and they used the same Ford and Chevy chassis as National.

The 1994 Winnebago Adventurer in 29' had the following GVWR - Ford =15,200 lbs and the Chevy = 14,800 lbs. The 32' and 34' both show Ford = 17,000, Chevy 16,000. So in all cases the Ford has a higher weight rating than the Chevy despite the 16'" tires. Bottom line is the weight capacity is restricted by the chassis and not the tires.

All that said, checking the diameter of the brake rotors would be a good thing although it seems unlikely that the lower GVWR Chevy would use bigger brake rotors than the Ford, but never assume. The possible difference I mentioned before in the center hole of the wheels is also important.

We can speculate back and forth but your best bet is to find the correct Ford wheel or make friends with someone who has an older Ford motorhome and see if his spare tire/wheel will fit your Chevy hub. THAT will be the final word.

SteveLevin · 10-10-2010, 11:09 PM

Quote:

Originally Posted by Nick-B

Load rating for the LT235/85R16 tires is 3042 LBS at 80 PSI
This size is what most of us older Ford chassis guys run. There isn't much else to choose from for the high load 16's.

Just for correctness, that's a single tire load, it's 2756 for duals. So 11,000 (11,024 if we are being precise) pounds on the rear axle and 6,000 (6,084 again for precision) for the front axle.

Steve

MEXICAN · 10-11-2010, 07:21 PM

My motorhome is a 31ft, looks like is more trouble than is worth, i will just keep it the way it is, it had worked just fine for years, i will just make sure to have 2 spare tires when i go out of the country.
Thanks for the help guys

tropical36 · 10-21-2010, 02:23 PM

This would be a rare conversion indeed and by the time it was accomplished, you'd have a few bucks in it. Even so, after checking the rig on the scales and the load rating from the tire chart, you might be good to go if you don't mind less ground clearance, a lower gear ratio and a speedometer/odometer thats now off by some degree.

MEXICAN · 10-21-2010, 08:03 PM

Quote:

Originally Posted by tropical36

This would be a rare conversion indeed and by the time it was accomplished, you'd have a few bucks in it. Even so, after checking the rig on the scales and the load rating from the tire chart, you might be good to go if you don't mind less ground clearance, a lower gear ratio and a speedometer/odometer thats now off by some degree.

WOW, i never took that into consideration