33` Handling

[gilcolog]

Looking at a 33 DP that has been well cared for. Space is comfortable and meets our needs. Wheelbase to length ratio is 48%. I have driven it a few miles and it seems to handle well and ride is ok. My main concern woud be in a panic situation whether it would have a tendency to roll or otherwise lose control.
This coach has been on the market for at least since spring and I wonder if
others have a hesitancy to buy, because of safety issues related to control. Price has been reduced and now would be a good time to buy.
I have come to appreciate the collective wisdom on this site and look forward to your counsel.

[JumboJet2]

I recently purchased a 35' DP and it drives very good. You might share more information and a person with the same DP might speak up.

[JFXG]

Originally Posted by gilcolog

Looking at a 33 DP that has been well cared for. Space is comfortable and meets our needs. Wheelbase to length ratio is 48%. I have driven it a few miles and it seems to handle well and ride is ok. My main concern woud be in a panic situation whether it would have a tendency to roll or otherwise lose control. ...........

gilcolog, it's gratifying to know you've done enough research to even check on the W/L ratio. Well done! You say "...I have driven it a few miles and it seems to handle well and ride is ok...". A test drive of few miles in the right conditions can sometimes tell a lot, but with a 48% W/L the likelihood is that a lot of trucks passing on the highway, or windy days, will be an adventure. The saving factor may be that it's a DP, so the chassis will be substantially heavier and the suspension inherently more robust.


Good Luck!

[Redridge]

with the right weight distribution, proper tire pressure and a steering stabilizer and a trim unit it will drive awesome... we love the tight turning radius and our 34' DP. The added Safe T plus and trim unit was a big help. Most of the weight on our coach is low so the center of gravity is as good as it gets... but yes, ours do get pushed around at very high winds (its not a tag axle), passing semi... not so much.

[Robby W.]

I have a 33' TropiCal DP that I have some handling issues with so I'm most interested in this thread.


I had new tires installed a year ago plus had full alignment. Didn't like the windy days on our 4k trip last winter. Notice that I'm getting, what I'd call, toe-in ware on the front tires. I'm going to have tires rotated and aligned at another shop soon. I've also looked into stabilizers.


Never heard of the "Wheelbase to length ratio is 48%".


Robby

[Filthy-Beast]

Originally Posted by Robby W.

Never heard of the "Wheelbase to length ratio is 48%".


Robby

Wheel base divided by total length. So the WB is 48% of the total length leaving a lot of MH behind the rear wheels. That can lead to a lot of tail wagging the dog. I've read the number you want is 53% or greater.

[Gary RVRoamer]

Since it is a diesel pusher, it seems doubtful that the rear overhang is all that excessive. With the weight of the diesel at the back, they rarely design them with much overhang. Therefore the overhang is probably split between front and rear. Still more than desirable, though.

Guessing at the numbers, a 33 foot coach with a 48% ratio would mean a 190" wheelbase. That's really short for a DP chassis and I wasn't even aware that any DP chassis were made that short. Even the older 32 ft Tiffin DPs had a 196" wheelbase (they handled OK, but that's a 51% ratio)).

So what coach are we talking about? And what brand of chassis?

[Rich-n-Linda]

The more overhang behind the rear axle, the less stable it will be. At 48% there is more vehicle BEHIND the rear axle than there is in front of it. Not good. You're going to get a lot of "the tail wagging the dog" syndrome. It won't be a pleasant driving experience in cross winds.

Our Mandalay is built on a 276" wheelbase and is 498" long. That works out to 55.4% and it drives like a dream. Very stable and easy to handle in windy conditions.


2006 Mandalay 40E, Cummins ISL 400 HP

[Gary RVRoamer]

At 48% there is more vehicle BEHIND the rear axle than there is in front of it

Isn't there some overhang on the front too?

[Rich-n-Linda]

Good point, Gary.

Yes, there is a bit of overhang at the front. Perhaps my "more behind than in front" statement isn't quite correct...but it's close.


2006 Mandalay 40E, Cummins ISL 400 HP

[gilcolog]

This is a Monaco Knight with Roadmaster chassis. W/b is 188"

[Gary RVRoamer]

Is that one of the 2002-2004 R4R or RR4R chassis that had the trailing arm problem & recall? If so, make sure it has been fixed. More info here:
Serious Problem On Some Monaco, Holiday Rambler & Safari Chassis - Chassis - FMCA Motorhome Forums

I guess I would be worried too. That is an awfully short wheelbase, and it's a minimal-design chassis to begin with. That version of the Roadmaster is nowhere near as good as it's RR8R brothers. Don't know that it is a disaster waiting to happen, but it's not the greatest either.

[Robby W.]

My Tropical DP is 406" long / 193" wheel base =.47536% and I do have tail wag on windy days. Now what?

[Gary RVRoamer]

Buy a different coach.

There really isn't much to be done. You can maybe add stiffer anti-sway (anti-roll) bars, but that's just a band aid.