Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 05-15-2013, 06:25 AM   #1
Senior Member
 
Join Date: Nov 2012
Location: Canada's East Coast
Posts: 117
Can you "Beef Up" a Chassis?

Hi folks,
I'm wondering what the legitimate methods of increasing GVWR are? Tires and shocks seem to be the easy answer but I'm wondering what other things can be done.
Thanks!
__________________

__________________
Maritimer is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-15-2013, 07:22 AM   #2
Member
 
Join Date: Jun 2011
Posts: 58
Contact your chassis manufacturer. You've provided no info on rig, chassis, etc. without that info nobody can help you. Tires 'might' get you more load depending on axles and current tires.
__________________

__________________
jdr159 is offline   Reply With Quote
Old 05-15-2013, 07:33 AM   #3
Senior Member
 
Sky_Boss's Avatar


 
Newmar Owners Club
Spartan Chassis
Join Date: Apr 2012
Location: ON THE ROAD...SOMEWHERE
Posts: 6,068
Probably not.

You can put on bigger tires but you can't beef up the axles beyond manufacturer specs so easily. Bigger tires also will raise other drive-ability issues such as ride height (DP), steering cut and tire clearance issues too. Don't forget brake systems are geared for the manufacturer's GVWR/GCWR too. THEORETICALLY, your brake system could handle GCWR but then you can't tow anything.

Personal opinion (you asked for them) is...don't be a crash test dummy. If, and only if, you can get the manufacturer to provide alternatives/approved modifications that you can afford and live with would I attempt to do that.

I'm certain someone will come behind and say some of us are just worry warts thinking chicken little is a prophet. LOL I must sayin'...
__________________
Don, Sandee & GSD Zeus. Guardian GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.
Sky_Boss is offline   Reply With Quote
Old 05-15-2013, 07:52 AM   #4
Community Moderator
 
JMonroe's Avatar


 
Newmar Owners Club
Spartan Chassis
Join Date: Oct 2009
Location: Deer Creek RV and Golf Resort, Davenport FL
Posts: 6,853
This seems to be one of those subjects we can expect to be revisited on a regular basis.

The problem is, you have no way of knowing what the limiting factor is. I doubt it's the tires or the manufacturer would simply have put tires with a greater load capacity on the rig and advertised a larger CCC. Is it the suspension, the brakes, the transmission or cooling system? Maybe the frame?

If you need more CCC, I suggest you sell this rig and buy one that better meets your current needs. It'll be safer for you, your family, and the rest of us sharing the road with you.

Good luck.
__________________
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
2017 GMC Acadia toad
JMonroe is offline   Reply With Quote
Old 05-15-2013, 08:09 AM   #5
Senior Member
 
Sky_Boss's Avatar


 
Newmar Owners Club
Spartan Chassis
Join Date: Apr 2012
Location: ON THE ROAD...SOMEWHERE
Posts: 6,068
Quote:
Originally Posted by JMonroe View Post
... I doubt it's the tires or the manufacturer would simply have put tires with a greater load capacity on the rig and advertised a larger CCC....
While I agree with most of what you said, in the interest of total fairness...

Newmar de-rated my Spartan MM IFS front axle from 14600 to 14200 for...drum roll...tire size. Yes, if my rig is properly balanced from left to right I can put the full 14600 on the front axle without having to run the maximum 120 PSI in my 305/70Rs. If I was perfectly balanced I would never need more than 110 PSI. I don't want to run more than 110 PSI simply because of ride quality. Newmar took the conservative route and reduced the axle rating for situations where the balance was not as even.

I have to assume this was a (pardon the pun) a balancing act for cost control. Clearly the drive and tag axles have no need for a 315/80Rs. My current tires will NEVER be stressed at all in the rear. Only the front tires are being put to the test. So, instead of 8 really expensive tires, I need 8 almost, really expensive tires.

Anyway...this should give the OP some more background on factors that are out of his/her control.
__________________
Don, Sandee & GSD Zeus. Guardian GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.
Sky_Boss is offline   Reply With Quote
Old 05-15-2013, 09:53 AM   #6
Senior Member
 
Join Date: Nov 2012
Location: Canada's East Coast
Posts: 117
Quote:
Originally Posted by jdr159 View Post
Contact your chassis manufacturer. You've provided no info on rig, chassis, etc. without that info nobody can help you. Tires 'might' get you more load depending on axles and current tires.
Well actually I don't have the rig yet so pretty tough to provide those details.
My query is just a general question after looking at several motorhomes with an NCC of 2K to 2.5K and wondering if there is a safe and practical method of increasing that capacity.
__________________
Maritimer is offline   Reply With Quote
Old 05-15-2013, 10:07 AM   #7
Senior Member
 
Sky_Boss's Avatar


 
Newmar Owners Club
Spartan Chassis
Join Date: Apr 2012
Location: ON THE ROAD...SOMEWHERE
Posts: 6,068
Quote:
Originally Posted by Maritimer View Post
Well actually I don't have the rig yet so pretty tough to provide those details.
My query is just a general question after looking at several motorhomes with an NCC of 2K to 2.5K and wondering if there is a safe and practical method of increasing that capacity.
It is also important to get any potential purchased weighed with fuel and water as you expect to use it. Gassers tend to load up the rear axle while DPs seem to have the most problems with front axle loads. Number of slides and location of them can make a big difference in axle loads. It is seldom possible to use the full NCC/CCC capacities because one axle will max out before you get there.

If you are looking at brochure NCC/CCC numbers be VERY skeptical. Those figures are based on units without any options but most MHs have some if not most options installed.

I think the bottom line is that you will want to pick a MH that has the CCC and axle loading you need to do what ever it is you want. If you want to travel with full water and such then that is important. If you think you can travel with 1/2 water so you can carry other stuff then that is your choice.

The cost of authorized modifications (MR_D can expand on that) that may be available but CO$TLY if you have to pay for them out of pocket. These mods can cost thousands of dollars and require new wheels and tires. If you are looking at used models you can go to the chassis manufacturer and validate weight limits and see if modifications are available.

Still...simply adding tires (which might require new wheels or could cause steering travel issues) is not something I would recommend. Too many other variables out there.

Good Hunting!
__________________
Don, Sandee & GSD Zeus. Guardian GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.
Sky_Boss is offline   Reply With Quote
Old 05-15-2013, 10:18 AM   #8
Senior Member
 
Ford Super Duty Owner
Join Date: Dec 2009
Location: Mcdonough, Ga.
Posts: 4,382
Not without a BIG BIG wallet. Remember not only brakes and suspension but wheel bearings and frame members are all figured into the chassis. Tires and the number one problem Engine cooling are also in play. The simple answer is NO!
__________________
1998 Pace Arrow 35 ft. F53 Ford V10 2012 Honda Civic toad
32 years mechanic at Delta Air Lines 15 year motorhome service manager. 3 popups....2 travel trailers....5 motorhomes....loved them all.
ga traveler is offline   Reply With Quote
Old 05-15-2013, 10:31 AM   #9
Senior Member
 
Country Coach Owners Club
Join Date: Jan 2006
Location: Redding
Posts: 3,412
Quote:
Originally Posted by Maritimer View Post
Well actually I don't have the rig yet so pretty tough to provide those details.
My query is just a general question after looking at several motorhomes with an NCC of 2K to 2.5K and wondering if there is a safe and practical method of increasing that capacity.

Well there may be safe and somewhat practical methods of increasing the capacity.

One sure way is remove the weight of unnecessary items from the current status.

Any other methods would require a change of the axles, frame, tires, wheels, etc to increase the gross vehicle weight rating. That statistic is provided by the final manufacturer of the rig. Their calculation is not made available to the consumer so you do not know what engineering parameters limit the GVWR to its current status.

You might be able to increase the GVW capability of the rig with mechanical changes, but changing the legal certification would likely be a costly and involved process.

If it important, buy a rig already certified to your needs.

To do that, obtain the current axle weights of a target rig, and calculate the available ccc as it sits.
__________________
Dean
1995 CC Magna #5280
C8.3L 300hp Cummins, 31,000lbs
deandec is offline   Reply With Quote
Old 05-15-2013, 10:39 AM   #10
Senior Member
 
Oldme's Avatar
 
iRV2 No Limits Club
Join Date: Nov 2012
Posts: 456
It is my understanding that you can "beef up" anything you want.

However it does NOT change the legal ratings of your rig.
The GVWR is set by the manufacturer. They would have to change it.

What you may be doing is buying peace of mind by knowing exactly what is there.
Still you would be "at fault" for exceeding the GVWR if anything happens.
__________________
We are K&K for Kathy & Ken - Both retired.
She accounting, he Law Enforcement
Oldme is offline   Reply With Quote
Old 05-15-2013, 10:48 AM   #11
Registered User
 
mel s's Avatar
 
Join Date: Mar 2010
Posts: 8,777
Quote:
Originally Posted by Maritimer View Post
Well actually I don't have the rig yet so pretty tough to provide those details.
My query is just a general question after looking at several motorhomes with an NCC of 2K to 2.5K and wondering if there is a safe and practical method of increasing that capacity.
Maritimer
Since you don't have the rig yet, this is my suggestion:
Find and buy what you need/want.... don't to try to make a silk purse out of a sows ear.
As the saying goes, "If you put lipstick on a pig it is still a pig"!
My 2 cents
__________________
mel s is offline   Reply With Quote
Old 05-15-2013, 05:03 PM   #12
Senior Member
 
vito.a's Avatar
 
Monaco Owners Club
Join Date: Oct 2009
Location: Tucson, AZ
Posts: 1,522
Generally the limiting load factor for gross weight is the brakes. Although you could retrofit larger brakes, you would then run into the next closest limiting factor. In Canada, that will probaly be the axles and tires. You could upgrade these, but then the next limiting factors come into play.

As someone else suggested, keep shopping until you find a motor home that better suits your needs.

I'm not sure what your budget is, but the early Monaco Windsor's and Dynasty's have a large gross weight margin and can be a bargain with some careful shopping.
__________________
vito.a is offline   Reply With Quote
Old 05-15-2013, 06:13 PM   #13
Senior Member
 
WeatherTodd's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Nov 2009
Location: FL
Posts: 1,147
Wink

Quote:
Originally Posted by Oldme View Post
It is my understanding that you can "beef up" anything you want.

However it does NOT change the legal ratings of your rig.
The GVWR is set by the manufacturer. They would have to change it.

What you may be doing is buying peace of mind by knowing exactly what is there.
Still you would be "at fault" for exceeding the GVWR if anything happens.
So OEMs have some magical power that say a capable fabrication shop with mechanical engineers on staff wouldnt?

Certain components could be changed to increase load. Cost wise... well the benefit would have to be weighed against the cost.
__________________
WeatherTodd is offline   Reply With Quote
Old 05-15-2013, 06:20 PM   #14
Senior Member
 
WeatherTodd's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Nov 2009
Location: FL
Posts: 1,147
Quote:
Originally Posted by mel stuplich View Post
Maritimer
Since you don't have the rig yet, this is my suggestion:
Find and buy what you need/want.... don't to try to make a silk purse out of a sows ear.
As the saying goes, "If you put lipstick on a pig it is still a pig"!
My 2 cents
My first gasser was a nonslide coach. It was turn key running unit but even at 10yrs old its age was showing. I easily exceeded the purchase price of the rig on refinements and upgrades. I learned alot modifying & upgrading that rig. Enough that the next RV I bought was a huge upgrade in chassis & finishes. Had I went in "blind" to the hobby... I might be saddled with a $100k rig worth $30k and $800 payments to match like one of my friends.
__________________

__________________
WeatherTodd is offline   Reply With Quote
Reply

Tags
chassis



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 01:12 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.