Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Keystone RV Forums > Keystone Tech Forums > Tires, Tires, Tires!
Click Here to Login

Reply
 
Thread Tools Display Modes
 
Old 04-25-2020, 05:54 PM   #1
traynoral
Member
 
Join Date: Oct 2018
Location: Chester
Posts: 30
Question Upgrade rim size and tires

Hi All,

I have a 2019 Keystone Cougar 32BHS. I am wanting to go to a larger wheel and tire size for several reasons, but the main reason is to gain a little height to level out the trailer with my truck. I have already had installed a two inch steel block under the leafs to get a little height which has also given me a little more wheel well clearance. My plan is to go from my 225/75 15s to 235/80 16s. As far as I can measure it looks like I have plenty of clearance to do this.

Has anyone done this on their Cougar Half Ton Fifth Wheel? If so, how did it work for you and what tire/wheel combo did you go with?
traynoral is offline   Reply With Quote
Old 04-25-2020, 08:40 PM   #2
bobbecky
Senior Member
 
bobbecky's Avatar
 
Join Date: Jul 2013
Location: Box Elder
Posts: 2,897
You will only gain 1.25” in height. Comparing specs on the Goodyear Endurance tires on Tirerack, the 15” tire is 28.3” in diameter and the 16” tire is 30.8” in diameter, so, for a difference of 2.5”, half of that isn’t much for what it’s going to cost to make the change, but that’s your decision if that’s what you want to do. It would have been cheaper to add another inch at your axles.
bobbecky is offline   Reply With Quote
Old 04-26-2020, 03:03 AM   #3
gearhead
Senior Member
 
Join Date: Jul 2013
Location: Liberty, Texas
Posts: 5,021
Before you spend money on tires be sure you can find wheels for your lug bolt pattern.
__________________
2018 Ram 3500 Laramie CC DRW LWB 4X4 Cummins Aisin 3.73
Reese Goosebox 20K
2018 Heartland Landmark 365 Oshkosh
2008 Bigfoot 25C9.4 LB Cabover
gearhead is offline   Reply With Quote
Old 04-26-2020, 04:01 AM   #4
notanlines
Senior Member
 
notanlines's Avatar
 
Join Date: Oct 2014
Location: Germantown, TN
Posts: 6,308
Al, can we maybe get a picture of your rig hooked up? Maybe tell us how much clearance you have at your truck bed right now...
__________________
Jim in Memphis, Wife of 51 years is Brenda
2019 F450 6.7 Powerstroke
2018 Mobile Suites 40RSSA
2021 40' Jayco Eagle
2001 Road king w/matching Harley sidecar
2021 Yamaha X2 Wolverine 1000
notanlines is offline   Reply With Quote
Old 04-26-2020, 05:08 AM   #5
traynoral
Member
 
Join Date: Oct 2018
Location: Chester
Posts: 30
Thanks for your replies.

It is a 6 5-1/2 bolt pattern so that part is not a problem for a 16 inch rim. I do have to replace the tires anyway, so my only optional cost would be the rims. Also, I should be able to get a little money for selling the old alloys as they are fairly new. The place that put the blocks in said that I should not go higher than two inches. I did look at going with 235/85s over 235/80s, however that will only give me 1 to 1.5 inches of clearance between my tandem tires, which I feel is too close.

My other reason to upgrading is I want to go to a better grade of tire (most likely the GY Endurance's) and with the larger tire size I will have more weight capacity. I don't plan on overloading the rig but would like to have that tire capacity buffer to be on the safe side.

What I am really wondering is if anyone has done a similar upgrade and how well has it worked for you.
traynoral is offline   Reply With Quote
Old 04-26-2020, 05:15 AM   #6
flybouy
Site Team
 
Join Date: Oct 2011
Location: Joppa, MD
Posts: 11,714
Quote:
Originally Posted by traynoral View Post
Thanks for your replies.

It is a 6 5-1/2 bolt pattern so that part is not a problem for a 16 inch rim. I do have to replace the tires anyway, so my only optional cost would be the rims. Also, I should be able to get a little money for selling the old alloys as they are fairly new. The place that put the blocks in said that I should not go higher than two inches. I did look at going with 235/85s over 235/80s, however that will only give me 1 to 1.5 inches of clearance between my tandem tires, which I feel is too close.

My other reason to upgrading is I want to go to a better grade of tire (most likely the GY Endurance's) and with the larger tire size I will have more weight capacity. I don't plan on overloading the rig but would like to have that tire capacity buffer to be on the safe side.

What I am really wondering is if anyone has done a similar upgrade and how well has it worked for you.
You will not increase weight capacity changing tires, that number is based on the suspension system, springs, axles, bearings, spindles, etc. You will gain a larger percentage of "cushion" above capacity. You can put the wheels/tires from a 18 wheeler under it and it's won't change the load capacity.
__________________
Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
flybouy is offline   Reply With Quote
Old 04-26-2020, 05:18 AM   #7
traynoral
Member
 
Join Date: Oct 2018
Location: Chester
Posts: 30
Quote:
Originally Posted by flybouy View Post
You will not increase weight capacity changing tires, that number is based on the suspension system, springs, axles, bearings, spindles, etc. You will gain a larger percentage of "cushion" above capacity. You can put the wheels/tires from a 18 wheeler under it and it's won't change the load capacity.
Thank you. Yes, I do understand that. I am just trying to make sure my tires are not the "weakest link" as far as capacity goes.
traynoral is offline   Reply With Quote
Old 04-26-2020, 05:57 AM   #8
CWtheMan
Senior Member
 
CWtheMan's Avatar
 
Join Date: Feb 2010
Location: Taylors, SC
Posts: 3,031
I deleted my previous post. Your change in height is just to radical to do without certification. I don't have the experience to do it's math.

I will say this though. There are ST225/75R15 LRF all steel tires already on the market.
CWtheMan is offline   Reply With Quote
Old 04-26-2020, 06:33 AM   #9
JRTJH
Site Team
 
JRTJH's Avatar
 
Join Date: Mar 2011
Location: Gaylord
Posts: 26,841
We've got a couple of members that have changed from 14" to 15" wheel/tire combinations. I don't remember offhand anyone that has converted from 15's to 16" that has reported their experience in previous posts. There have been a couple who "talked about it" but I can't remember anyone actually saying, "I changed from 15's to 16's and this is how it went"....

You may be in "uncharted waters" but that certainly doesn't make it impossible to do... Heck, people have been putting 24" wheels on Suburban SUV's for years now, some even with "spinning hubcaps"... They survived, I don't see any reason why you wouldn't survive too.

If you decide to do it, please document your experience and observations !!!
__________________
John



2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS
JRTJH is offline   Reply With Quote
Old 04-26-2020, 06:35 AM   #10
traynoral
Member
 
Join Date: Oct 2018
Location: Chester
Posts: 30
Quote:
Originally Posted by JRTJH View Post
We've got a couple of members that have changed from 14" to 15" wheel/tire combinations. I don't remember offhand anyone that has converted from 15's to 16" that has reported their experience in previous posts. There have been a couple who "talked about it" but I can't remember anyone actually saying, "I changed from 15's to 16's and this is how it went"....

You may be in "uncharted waters" but that certainly doesn't make it impossible to do... Heck, people have been putting 24" wheels on Suburban SUV's for years now, some even with "spinning hubcaps"... They survived, I don't see any reason why you wouldn't survive too.

If you decide to do it, please document your experience and observations !!!
I absolutely will. Thank you for your feedback.
traynoral is offline   Reply With Quote
Old 04-26-2020, 03:28 PM   #11
hornet28
Senior Member
 
hornet28's Avatar
 
Join Date: Jul 2017
Location: Muskegon
Posts: 356
Do it. You know you can get the wheels and the difference in height has be taken care of by the 2" blocks. As far as naysayers some wouldn't change the wattage on a light bulb without an investigation
__________________
07 GMC CC LB dually LBZ, Idaho Rob EFI, DeeZee boards, 50 gal TransferFlow inbed tank
05 32' Montana Mountaineer 5th wheel 2 slides
1941 Ford cpe 454/700R4
1917 T roadster 270 Hemi/4 spd
34' car trailer w/63" semi sleeper on the front
hornet28 is offline   Reply With Quote
Old 04-26-2020, 06:30 PM   #12
fjr vfr
Senior Member
 
Join Date: May 2018
Location: Mechanicsville
Posts: 472
I considered going to 16" wheels, but then I balked. When we are staying places I always walk around and see what other people are doing. If I see something interesting I'll often ask about it. Most everyone is happy showing their trailer mods.

With that said, I have seen a good number of raised trailers. Many owners welded up a sub frame and attached their spring mounts below. I've come across people in the south west that spend a lot of time boon docking on BLM land and wanted lots of clearance. Some trailers are very high.
So with that I'd say instead of blocking your axle maybe you could look into welding something to the frame so you can lower the whole suspension.
But before doing anything you should post some pictures here. Maybe you don't need to do anything?
fjr vfr is offline   Reply With Quote
Old 04-27-2020, 12:36 AM   #13
CWtheMan
Senior Member
 
CWtheMan's Avatar
 
Join Date: Feb 2010
Location: Taylors, SC
Posts: 3,031
Does anyone read their vehicle’s certification label?

There is a list of equipment items in the vehicle certification regulation that can be changed without hindering the intent of vehicle certification without being certified. Tires, wheels, brakes, axles etc.. are on that list. Chassis modifications of any sort are not on that list.

"This vehicle conforms to all applicable US Federal motor vehicle safety standards in effect on the date of manufacturer."

See 49 CFR part 567, vehicle certification/modification.
CWtheMan is offline   Reply With Quote
Old 04-27-2020, 06:09 PM   #14
lunge motorsport
Member
 
Join Date: May 2018
Location: San Ramon
Posts: 75
Interesting post with a lot of differing viewpoints...


For me, safety is paramount. Someone mentioned changes that do not meet the regs regarding certification by the manufacturer.
The manufacturer of my rig is Keystone whose certification label was attached to a coach with a GVWR of 10,300 lbs. The 2 axles were rated at 4400 lbs each with 3 extraordinarily flimsy 3/16'' u brackets on each side supporting 2 axles. I've read many posts about these tearing off of the frame due to side load shear and I watched and heard my old leaf spring axles squeal in pain as I jack knifed the rig to get into a very tight camping space. Most rigs are certified with undersized wheels and tires , marginal axles, brakes, and leaf springs to locate the crappy mess.


Okay, there will be legal ramifications if your mods fail and you take an innocent out, not to mention the lifelong guilt that would accompany it. But I fully endorse well researched and executed mods that are superior in every way to the junk that is certified by the manufacturers. I raised my rig 3'' to obtain a level towing attitude and the mod included new 17'' rims. It was expensive even though I performed all the work. The coach now has real suspension, brakes, wheels and tires and tows like a dream. It is not certified by anyone but me but I will bet my life and yours on it!


Waiting for a reasonable argument...



Photos in my albums
Cheers
__________________
Truck & trailer...yes
They have many features and upgrades, more than I can list, so much, did I mention they are well equipped, I don’t know if I have enough room here....and I really don’t think you care anyway, so nope
lunge motorsport is offline   Reply With Quote
Old 04-27-2020, 06:24 PM   #15
Roscommon48
Senior Member
 
Join Date: Dec 2018
Location: grand rapids
Posts: 596
you might want to go up a 'rating' while at it. make sure the wheels match the psi of the tires.
Roscommon48 is offline   Reply With Quote
Old 04-27-2020, 11:05 PM   #16
notanlines
Senior Member
 
notanlines's Avatar
 
Join Date: Oct 2014
Location: Germantown, TN
Posts: 6,308
Darrel, I'm curious how you feel you benefited by the 3" to tow level. Was this to add clearance to the bed of the truck?
__________________
Jim in Memphis, Wife of 51 years is Brenda
2019 F450 6.7 Powerstroke
2018 Mobile Suites 40RSSA
2021 40' Jayco Eagle
2001 Road king w/matching Harley sidecar
2021 Yamaha X2 Wolverine 1000
notanlines is offline   Reply With Quote
Old 04-28-2020, 01:55 AM   #17
CWtheMan
Senior Member
 
CWtheMan's Avatar
 
Join Date: Feb 2010
Location: Taylors, SC
Posts: 3,031
Quote:
Originally Posted by lunge motorsport View Post

It is not certified by anyone but me but I will bet my life and yours on it!


Waiting for a reasonable argument...



Photos in my albums
Cheers
That's why we have rules and regulations to guide us.

You're probably in violation of federal vehicle certification regulations. Are you a certified vehicle modifier?

Refer to: 49 CFR part 567.6
CWtheMan is offline   Reply With Quote
Old 04-28-2020, 08:15 AM   #18
travelin texans
Senior Member
 
travelin texans's Avatar
 
Join Date: Nov 2017
Location: Picacho, Az
Posts: 6,809
Quote:
Originally Posted by CWtheMan View Post
That's why we have rules and regulations to guide us.

You're probably in violation of federal vehicle certification regulations. Are you a certified vehicle modifier?

Refer to: 49 CFR part 567.6
Highly doubt he is nor any of the rest of us that have made necessary modifications to improve ride or functionality of our rv. Apparently upgrading a load range or size on tires will/has already broken the regulations.
Plus I personally have NEVER been stopped nor questioned by anyone, whoever may have that responsibility, as to whether any of those modifications were done by a certified individual as per the referenced code mentioned above. I have however been asked by several how I've done some of the mods so that they can do the same.
Not trying to be argumentative, but if they would build them better, maybe 1 step above rather than just barely enough, to begin with these modifications wouldn't be necessary.
__________________
Full-timed 10+ years
Sold '13 Redwood FB
Traded '13 GMC Denali DRW D/A
Replacement undetermined
travelin texans is offline   Reply With Quote
Old 04-28-2020, 08:52 AM   #19
flybouy
Site Team
 
Join Date: Oct 2011
Location: Joppa, MD
Posts: 11,714
The way I see it it's mainly a result of our society being over litigious and the accepted idea that someone must "pay" for your loss (either real or imagined). Combine that with an overzealous government that wants to regulate everything and doesn't understand how most of it works.

Don't get me wrong, if someone (individual or company) does undo harm then they should be penalized but good gracious the television just bombards use with Lawyer commercials telling us how to get rich. Regulations are necessary but what seems to be missing is the good old common sense.

Wasn't that many years ago that you could go to a welding shop and get a hitch made or a modification to "beef up" a suspension. There were "spring shops" that would re-arch or add a leaf. Those places are disappearing and I miss them. Typically it was owned and operated by a guy that wasn't an MIT engineer, may or may not have been a certified welder, but knew what you needed, could "rig it up" and if it was going to get you into trouble tell you no and refuse to do it. His most valuable skill was the implementation of common sense. They don't teach that at the "trade schools" or certification programs unfortunately. Now everyone must be "certified" and become "technicians or specialists" . That's a great word. I saw a news bit last night on "Certified Pre-Owned Cars" and how most of them are meaningless. By definition, they are certifying that someone bought the car, used it, and now it's for sale again. And people are eating it up.

I'll take a a person that's experienced that's got common sense but that's a rapidly dying breed these days.

JMHO
__________________
Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
flybouy is offline   Reply With Quote
Old 04-28-2020, 09:24 AM   #20
JRTJH
Site Team
 
JRTJH's Avatar
 
Join Date: Mar 2011
Location: Gaylord
Posts: 26,841
Since I got my first driver's license (at 15 years old) I've been "modifying vehicles" it started by changing out the 1950 Chevy turtleback 2 door coupe tires for whitewalls and changing those DAMN itchy wool OEM seat covers for plastic ones. Even my 1968 Plymouth Barracuda SS I installed a "mini-8 and two speakers" in addition to "huge redwall rear tires" called cheater slicks...

Almost every 4x4 from the first 1960 Ford F100 got 35" tires to replace the "bicycle tires from the factory". I think I supported Micky Thompson for most of my adult life.

The 1972 Dodge truck needed a 2" receiver, so the local welding shop "built one and welded it to the frame". When I bought our 1975 Blazer, that same shop "cut the hitch off the Dodge and welded it to the Blazer."

I can't count the number of times I've had a leaf added to the rear springs, or added "overload shocks" with spring packs attached, to lift the rear end so those "big Micky Thompson's won't rub the wheelwells when driving on a washboard gravel road"...

So, I'm not one to "be afraid" of putting 16" wheels/tires on a Cougar that came with 15" wheels that offered ZERO weight capacity beyond the axle ratings or the trailer GVW.

If this were catechism, I suppose I'd have my knuckles bleeding from that damn ruler.... But, living in a "free country" so far, I've never "bled for changing wheel/tire size".....
__________________
John



2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS
JRTJH is offline   Reply With Quote
Reply

Tags
tires, upgrade

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by the Keystone RV Company or any of its affiliates in any way. Keystone RV® is a registered trademark of the Keystone RV Company.


All times are GMT -8. The time now is 10:22 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.