Wheelbase to length ratio - how important?

Interesting discussion. We have a large diesel pusher and my initial thought was that our percentage would be higher than average.  In fact, our wheelbase is 279" (not including the tag axle) and overall length is 43' - 7" or 523".  Ratio is 279/523 or 53.35%.

Add half the distance between the drive and tag axles to the wheelbase measurement.

Ned said:

Add half the distance between the drive and tag axles to the wheelbase measurement.

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Thanks Ned.  That adds 24" to the wheelbase.  New numbers are (279+24)/523 which equals 57.9% for our Journey.

One aspect that is rarely mentioned in these discussions is the actual skills of the drivers. If one has great seat of the pants skills, the hurtling wobbly effect is much less bothersome than for a driver that is fearful of big scary trucks while driving a sedan.

Bill

If I was traveling cross country, or even up and down the east coast, from Fl. to New England, I'd rather drive my car like I did this summer, than my motor home like I did last summer.  The trip in the MH beat me up pretty bad. 
But overall, given the opportunity, I'd rather fly, but that wasn't an option this year, as I needed my car while I was up there for the summer.  But when I went up for a long 5 day weekend in April, I flew up, stayed in a hotel and rented a car.  Flying up took 2 1/2 hrs. each way, vs driving, which takes 2-3 days each way (or 21 hrs. if driven straight through).
I would rather stay in a campground, with my RV, than a hotel room, but the travel part of driving a large house on wheels for multiple days on end, and then having to turn around, and do it all over again, when heading back home, is what gets to me.....well that and the traffic, and road construction.

Having flown a million miles (I've got the permanent gold card to prove it), I'll be happy if I never get on another airplane to travel. Way too much hassle! I'm retired and in no hurry so I'll just meander along at 300 miles per day.

Ernie

If I am doing the math correctly my Class C Winnebago Aspect 30J has an overall length of 388" (32'-4") and a wheelbase of 220". 388/220=0.5670 (100) = 56.7%, which is good....right(?).

Ernie n Tara said:

Having flown a million miles (I've got the permanent gold card to prove it), I'll be happy if I never get on another airplane to travel. Way too much hassle! I'm retired and in no hurry so I'll just meander along at 300 miles per day.

Ernie

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I'm retired as well, but I just can't meander.  I need to get where I'm going.  I'm happy when I'm home, and I'm happy when I arrive at my destination, but that travel time in between is hell.  I'm not one who enjoys the trip, as much as the destination, except when I'm on my bike, out in the open, enjoying the freedom, that is my stress relief.
I guess I'm just too much of a Type A personality, to just take my time to get somewhere.  I like to get there, get settled in, and stay there, and not move around from place to place, but to settle in, and enjoy my time there, for whatever the purpose of going there is, then to go back home, to where I'm most comfortable, and where all my friends and stuff are.  I always enjoy, and look forward to going back up north, to visit family (kids and grandkids) and old friends, but look forward to getting back home.  That's why I could NEVER full-time in a motor home, wandering aimlessly, with no home base to go back to.

Oscar Mike said:

If I am doing the math correctly my Class C Winnebago Aspect 30J has an overall length of 388" (32'-4") and a wheelbase of 220". 388/220=0.5670 (100) = 56.7%, which is good....right(?).

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Yes, it's good, very good.

Interesting reading.
Something I never thought about.
I knew that I just did not like long overhangs for some reason.

So I guess our small Class C is good at:
174? wheelbase
24? 2? length = 290?

Ratio = 60%

I know it handles very well and is a easy drive.

Thanks for the information.

Ernie n Tara said:

Having flown a million miles (I've got the permanent gold card to prove it), I'll be happy if I never get on another airplane to travel. Way too much hassle! I'm retired and in no hurry so I'll just meander along at 300 miles per day.

Ernie

Click to expand...

300 miles per day? You call that meandering? My trips are less than 100 miles per day. LOL  To each his own.

I'm not one who enjoys the trip, as much as the destination, except when I'm on my bike, out in the open, enjoying the freedom, that is my stress relief.

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Riding is one reason my trips are often under 100 miles per day. The bike I pack as a toad took us two-up right down a cobblestone hill to the shore of Lake Ontario. Also to a lock on the Rideau Canal to watch it be hand operated by a lock master and two college interns. And six miles back into the mountains in Georgia. It has surprised me as one of my favorite motorcycles ever.

A while back I read that someone followed his rule of 3s.

Drive 3 hours before resting
Drive no more than 300 miles a day
Have the RV setup in camp by 3PM

I have tried to remember them as they seem reasonable
and allow you to Enjoy The Journey.

Ned said:

Add half the distance between the drive and tag axles to the wheelbase measurement.

Click to expand...

Can you tell us why to do that Ned?

Ken

That's what I read when I researched wheelbase.  Sorry, I don't recall the document or article, but I'm sure Google will find it for you.

The official wheelbase (per FMCA) of a vehicle with a tag axle is the midpoint between the two axles. This is important for the turning radius on vehicles without the ability to lift the tag axle, the effective wheelbase. With a tag axle that lifts, the effective wheelbase for turning is the centerpoint of the front axle, the one left in contact with the ground.

For overhang, the important number is the angle of departure. That is the angle from the bottom of the rearmost tire to the lowest part of the rearmost structure that will drag when going over a bump, backing up to an incline, etc. For the front of the vehicle it is called the angle of approach. The shallower the angle the more likely you are to drag. I don't know which article Ned read, and I'm not inclined to go looking for it, but I'm guessing that the intent of adding half of the distance between the axles is to get the effective wheelbase for overhang percentage. A number which can be misleading.

The reason that a simple wheelbase to total length percentage is misleading, is because it does not take into account where the axles are located on the vehicle. To illustrate, think about where the front wheels are in a van type vehicle compared to a conventional truck. Much closer to the front of the vehicle, right? If the wheelbase and total length of the two vehicles were both exactly the same, the overhang in the rear of the van type vehicle would be longer than the conventional truck vehicle. Wheelbase is the same for both, overall length is the same for both, but the van will drag the back bumper much more often than the truck.

Motorhome manufacturers have to balance the weight of the vehicle onto the axles so that neither (none) are overloaded yet the angle of departure is sufficient to minimize dragging. Sometimes in order to reach a price point they sacrifice weight balance or overhang.

Ken

Want the load math?

http://www.physicsforums.com/showthread.php?t=707170

http://www.loadxpert.com/lx/en/lx.htm