How much wheel base and length effect handling and steering?

[DAS26miles]

We are looking to move up from our Class C Minnie 22 ft with 138" wheel base. I test drove a New class C that was 32' 3" with a 220" wheel base. I like to ride down the road, but turning was something else. couldn't make the turn into the dealers driveway without backing up.
Question, the actual length of the MH we want is 28' 1" with a 202" wheel base. 4' 1' shorter than the one we test drove and 18" shorter wheel base. The actual one we were interested in was in the showroom, so not readily available for a test drive that day.
Would the differences in shorter length and wheelbase make enough difference in the turning or is it just the nature of the beast.
I am spoiled with our short length and wheelbase and can easily make U turns, park and back up. This is a whole new experience and I wonder about backing into site and maneuvering in tight CG roads with their trees.

[DAS26miles]

I know exactly what you are all saying as I weighed my 22 foot Minnie and found to be really light in front. The Stowaway storage bin on receiver added 250 lbs, plus my black and grey tanks are behind the era axle. We try to always dump our tanks before leaving the CG, but not always possible dry camping. I have adjusted the tire pressures per Michelin's table based of axle weights. I don't like putting stuff in the cabover because of rainy the center of gravity.

Anyway, that's all nothing new to me. Real concern was the turning radius on that longer length and wheelbase. Again, during the test drive with the longer MH and having to make tight right turn, pulled far forward to make the turn the steering didn't turn enough. Obviously those u turns at Rincon Parkway are out. I wonder what the turn radius is on the one we are interested in?

Went online to Ford and found the curb to curb turning diameter for my E-350 138" wheel base, it's 48.6 feet
The E-450 with a 176" wheel base is 60.3 feet.
Since the Forester we are looking at has a 202" WB , it's been extended. So I can expect it to be larger turning area than the 60 feet. Only way to know will be to test drive it and maybe go to a parking lot with cone and measure.
Tried doing some math. The ration of WB to curb to curb is .35. So 202" x .35 equal 70.7 or 70-71 feet curb to curb.

[j-d]

I remember one long thread where handling was bad an alignment, pressures, add-ons just didn't get it. They finally traded it in. Name brand, too. I truly believe Floor Plan dictates Wheel Base, even in brands that should Know Better. Back on that thread, I posted pix of two RV's. If you disregard the cab-over, the ones that look like the rest of the "house" is balanced on the Rear Axle are the problem ones. Since the weight of the house is borne almost entirely be the rear axle, rear has too much load and front doesn't have enough. Then there are those where there's clearly more house (not counting cab-over) in front of the rear axle than behind. The one in GotSmart's signature is like that. By the time you get to the 31-ft C's nearly all are like that. The axle position does two things: First, unloads part of the weight from the rear axle. Second, that unloading goes to the front axle where it's needed for handling/tracking.

[ron_dittmer]

TyroneandGladys wrote:
Be aware since it will not be loaded for travel that any weight added behind the rear axle will take weight off of the front axle. for example location of water tank if it is behind the rear axle it will take huge amount of weight off of front axle when filled.

This is so true, just like what happens with a school ground teeter-totter.

[TyroneandGladys]

j-d wrote:
Based on numbers, shorter one has a 60% ratio of WB to length and the longer one is a little less favorable at 57%.

That ratio tries to identify good handling, which is in turn based on good weight distribution. So, even though 60% is very good (I think 54% is considered minimum), the real issue is the actual weight distribution. It'll change as you load it up for travel, so where is the Storage, how will you load it, where are Tanks and will they be full/empty, what will you carry on the back, etc. etc.

You want at least 1/3 of true, loaded weight on the front axle. Some say at least 75% of front axle rating. If it's a new E450, then 75% of 5000# or 3750# and that's minimum. So include a truck stop in your test drive and get the actual total and axle weights now. That's a starting point. Some mid-size C's, say 26-29-ft, have a short wheelbase and heavy rear overhang. That's because the stylist wants to offer walk-around-queen in smaller coaches. UNLESS the wheelbase is adequate, that results in poor handling from a light front end, and possibly an overloaded rear axle. By your numbers, I don't think that will happen in either of the coaches you're looking at. Unless you hang two motorcycles off the back...

There have been posts from people because of the design of there motorhome they are unable to get enough load on the front axle and have terrible handling issues. IMHO very important to weigh it before buying and be able to verify that you do not run into that problem. Be aware since it will not be loaded for travel that any weight added behind the rear axle will take weight off of the front axle. for example location of water tank if it is behind the rear axle it will take huge amount of weight off of front axle when filled.

[carringb]

FWIW - When QuadVan converts vans to 4x4, they reduce the turning circle by about 10'. It's a pretty dramatic improvement in wheel-cut angle when they install a solid front axle. I decided to go with with an F550 axle, which is 5" and turns even sharper (so my van will have a smaller turning circle than my Fiesta!).

I'm sure they could do a 2WD solid axle conversion if anyone were interested, to get the turning benefits without the extra cost of full 4x4.

[DAS26miles]

Very interesting comments. I know that I need to pull further into the intersection before starting my turn. I was just surprised at the inability to turn the wheel tighter and the response in the turn. I guess I won't know until I drive the actual one were are interested in. We should of asked the salesman to test drive the 27 ft model, but then it has a 193" wheel base and 28' 4" in length. That would be 9" shorter on the wheel base instead of 18" longer but closer to the same overall length..
Right now with our 22ft class c we have no problems parking as it's about the same size as a full size crew cab with 8' bed. We do so much camping at National and State parks and watch the larger RV's struggle to maneuver around turns and parking in their site. Seen them scrap trees and rock and run over curbs and stops. But it's only 6 feet longer and only 4feet if you count our Stowaway cargo bin on the hitch.

[fortytwo]

The wheel cut angle of Class C's is a challenge as it is designed for a basic van of 20 feet or so. Pretty nimble. That nimbleness gets progressively worse as the wheelbase and frame length are extended. There is no way to change the wheel cut angle. Because class A chassis are designed considering maneuverability of a 40 foot vehicle in mind, a 40 foot diesel pusher turns better than a 30 foot class C. In both as the length increases so does the need for the drivers butt to be further into the intersection before beginning the turn. A few years ago I saw the new owner of a 45 footer drop the right rear wheel into a 6' ditch by entering the turn as if he were in a car. Had enough money to buy the MH but not enough for driving lessons apparently.

As class C's have continued to grow in length you have to weigh the convenience of the class C house design with the compromises in maneuverability.

[carringb]

ron.dittmer wrote:
The Ford has a bigger turning radius than the Chevy. Something to keep in-mind about that.

I don't think that's the case. For the 138" wheelbase Ford lists a 48' turning circle vs 49' for the 135" wheelbase Chevy 3500. I'm pretty sure all wheelbases for both models have the same wheel cut angle.

[ron_dittmer]

The Ford has a bigger turning radius than the Chevy. Something to keep in-mind about that.

I personally would be concerned over maneuverability if you primary spend time in national parks and such. Your 22' Minnie Winnie is ideal. Not so much with the 28'.

[Healeyman]

We moved up from a 22 foot Class C



The 22' also had the same wheelbase as our Suburban.

to a 28 foot Class C.



The biggest difference that I have found is that you must go MUCH deeper into a corner before starting a turn otherwise you'll run the rear wheels over the curb.

Other than that, everything else is pretty familiar.

Tim

[j-d]

Based on numbers, shorter one has a 60% ratio of WB to length and the longer one is a little less favorable at 57%.

That ratio tries to identify good handling, which is in turn based on good weight distribution. So, even though 60% is very good (I think 54% is considered minimum), the real issue is the actual weight distribution. It'll change as you load it up for travel, so where is the Storage, how will you load it, where are Tanks and will they be full/empty, what will you carry on the back, etc. etc.

You want at least 1/3 of true, loaded weight on the front axle. Some say at least 75% of front axle rating. If it's a new E450, then 75% of 5000# or 3750# and that's minimum. So include a truck stop in your test drive and get the actual total and axle weights now. That's a starting point. Some mid-size C's, say 26-29-ft, have a short wheelbase and heavy rear overhang. That's because the stylist wants to offer walk-around-queen in smaller coaches. UNLESS the wheelbase is adequate, that results in poor handling from a light front end, and possibly an overloaded rear axle. By your numbers, I don't think that will happen in either of the coaches you're looking at. Unless you hang two motorcycles off the back...

[carringb]

A 28' with a 202" wheelbase should still handle well and have good stability, as the wheelbase ratio is better than the 32' with a 220" wheelbase.

[the_bear_II]

I always advise to get the longest, biggest RV you want and can afford. You will become comfortable with driving it after just a few trips.

Sure longer RVs may be harder to maneuver but you will learn how to overcome any problems.