Changing Fifth Wheel Tires/Wheels from 15" to 16"

[chuckwagon]

I have a 2007 Gulfstream Canyon Trail Fifth Wheel Model 29RLFW with OEM 225/75r15 tires. 

I had a blowout yesterday and am looking at some new tires. After reading some threads on this forum and others I have decided to see about upgrading to a 16 inch wheel.

What do I need to measure to see if I have enough clearance for these tires?

The new tires I am wanting (Michelin XPS rib 225/75R16) are 1.1 inches larger in diameter.

Thanks to all for your help.

Chuck

 

[Gary RV_Wizard]

You need clearance around the wheel wells (fenders) to allow the suspension to flex without bumping the tire into the fender. Difficult to say how much that is because it depends on the suspension.  The extra 1.1" of diameter will subtract 1/2 of that amount from the existing clearance at the top and on each side. A long as the current tire is not real close, you should have room for another 0.55 inches of tire.

If you change the entire axle instead of just the wheel and tire, you can get substantially larger brakes along with the bigger wheels and most trailers with 15" wheels could use that improvement. It is a surprisingly inexpensive upgrade, since the tires are the major expense and you are buying them anyway. And you might get a trade-in on the old axle, since it is likely still  in good shape.

 

[BruceinFL]

When I changed mine on a previous 5er I had, I called the factory and they said no problem. Maybe you can call Gulfstream and ask them.

 

[huronwoods]

I replaced the 15in wheels on our Keystone Laredo with 16in, after experiencing a tire disintegration. The clearance from the top of the original 15in tires to the underside of the slideout was marginal; the other side was OK.

I inserted 3/4in spacer shims between the axles and the leaf springs, thus increasing the clearance by that amount. I had 4 plates fabricated by a local shop for $50. Don't forget the holes for the locating pins (5/8in thru hole in the center of each plate). I had to replace the original U-bolts with new ones which were a bit longer. You shouldn't retorque a used U-bolt anyway....they are not expensive.

We used Firestone Transforce HT tires with excellent results. I've heard good things about the XPS Rib, although they are pricey.

 

[ffstreetdoc]

I had the same issue with our 2007 canyon trail, crappy carlisle tires, one exploded and 2 others had major tread seperation within the first 1,000 miles of use, i replaced them with Maxxis 8008 E rated tires, stayed with the 15" because i couldnt swing for wheels at the time and had to get tires for the next outing, but i intend on upgrading to 16" LT tires ASAP, i am happy with the Maxxis tires, 2,000 miles and no problems yet but i have very little confidence in ST tires and hate being held to 65MPH speed limits, not that i want to burn up the highway but i would like to keep up with traffic and not worry about having another tire grenade on the interstate..
Below is a link to a tire size calculator if you need it...

http://www.miata.net/garage/tirecalc.html 

 

[joer]

Just changed my wheels to 16 from 15 inch today.  I put on Cooper 225/75r/16 tires on at the suggestion of our local tire shop.  These are not the most expensive but certainly not the cheapest tires available(130.00 ea).  I am making this change after many ,many blowouts on  carsile,towmaster,denman,secura, and then carsile load range E 15 inch st tires.  Fortunately I had enough room to install the 16's since they are just one inch greater diameter than the 225/75/15 tires.  The new tires are LT and not St tires intentionally.  Time will tell if this solves my tire(until now all imported ) problems.  The tire saga continues.    joe

 

[Gary RV_Wizard]

Hope this works out for you, Joe. Let us know.

 

[Santan40]

Very interested in how the LT Tires are working out for you, I have almost the same trailer as you and am sick of ST tires! I see you installed spacers under your axle to get some distance from the bottom of your trailer. How has it all worked out for you?

 

[Alfa38User]

Santan40

This is a very old thread (Sept 2009) so an answer may or may not be available. Gotta watch those dates!!!!

 

[Poppys 5th Wheel]

Santan40

This is a very old thread (Sept 2009) so an answer may or may not be available. Gotta watch those dates!!!!

Man, I never even saw that date I read it because the story is old and yet never changes or goes away. It seems to be one of the most common  and recurring discussions on any of the 4 or 5 RV trailer / forums I visit.

BTW, I swapped from 15" to 16" on my Cougar High Country early this spring. I likewise went to LT tires and, after about 3-4,000 miles, have had no problems. I did make a tire choice decision to begin with that was bad (too tall sidewall) and luckily my tire dealer gave me a full refund and we found a much better set which fit fine. So, make sure you don't just get any 16" tire without carefully checking the tires aspect ratio.

 

[BigLarry]

We had ruined 3 of the 4 original 215/75R 15 tires in the first 7000 miles we had our rockwood trailer back in 2009. I upgraded to 225/75 R15 E rated tires and had excellent results.  I think they were Load King trailer tires.  We pulled the trailer to Alaska with no problems.  The set lasted a little over 20000 miles and I replaced them with the same thing with excellent results again. I think the key is to make sure the load carrying capacity of your tires is well above the weight you're carrying.  Many times the factory tires just barely do the job.

Our new Cougar trailer has tires that are well above what's required.  It's going to be interesting to see if we have any trouble.  Maybe the manufacturers are getting a little smarter ???????  nnnaaa! I figure I'll have problems, just hasn't happened yet!

 

[joelmyer]

It ain't the miles, it's the months.

I went through two sets of Goodyear Marathons in four years.

I was thinking about bigger wheels but put on a set of Maxxi's in July '09.  So I'm at the 5 year mark with no problems & they look good, no little hairline cracks on the tread.

I'm going to run them another year & then another set of Maxxi's.

 

[Bamaman]

Switching from 15's to 16's will often require new hubs and axle in addition to new wheels and tires.  You might have to put spacers under the axle if there's not enough room in the wheelwells.

Your alternative would to stick with the Maxxis M8008--one of the only ST tires admired universally.  They're available in different rim diameters, too.