Forum Discussion

berreez's avatar
berreez
Explorer
Dec 15, 2013

Wheelbase to length ratio. What does it mean?

When you divide the wheelbase by the length of the motor home, you should have a wheelbase-to-length ratio of 53%. This ratio gives us a good idea of the handling characteristics you can expect from this vehicle.

From the above statement, is it better to have a number lower or higher than 53% if you what better handling?
  • The axle weight ratio can be a huge factor too. Our front carries about a third of the total MH weight giving each tire an equal load and does handle well.
  • I suspect the total handling characteristic of a rig is the sum total of everything about it. But for me, I'll stick with a good WB/Length ratio as a starting point.
  • I have a short wheel base 47%

    I put koni shocks a rear trac bar and did the chf. It not only handles awesome but it rides awesome now too
  • wallynm wrote:
    IMHO this is an old wives tale. Correct suspension and/or proper loading will provide an appropriate ride. This was dreamed up by some web site to sell reports and other information. They do not test drive anything before reporting.

    berreez wrote:
    When you divide the wheelbase by the length of the motor home, you should have a wheelbase-to-length ratio of 53%. This ratio gives us a good idea of the handling characteristics you can expect from this vehicle.

    From the above statement, is it better to have a number lower or higher than 53% if you what better handling?


    I've had both shorter and a longer wheelbase coaches and proper loading is more important than wheelbase length. I've never had a tail wagging problem with either without resorting to a trac bar. I think trac bars are sold to people that think that they can buy every accessory and their RV will drive like their family car.
    What is true is that those coaches with a shorter wheelbase will usually be more maneuverable if the rear overhang clears the obstacles.
  • The longer the wheel base the less wagging you would get. Plus less swing of rear of MH to left when you make a right turn. But nothing is free. The longer the wheel base the more difficult it becomes to manage in tight areas in shopping centers etc. Manufacturers try to accomplish both. Good handling in small areas and good handling on the hwy. Longer wheel base MH chassis cost more than short wheel base. (more steel required) RVers look mostly inside the box not under. So the question is cheap box on nice chassis or beautiful box on a cheap chassis. Most manufacturers try to balance it out. Some do better than others. However, look at TTs. Their rear overhang past the wheels is huge. Same with 5vers. So their seems to a lot of over concern. Rear and front trak bars help correct some of the short wheel base problems. Best way to choose is to drive it before you judge it. JMHO.
  • IMHO this is an old wives tale. Correct suspension and/or proper loading will provide an appropriate ride. This was dreamed up by some web site to sell reports and other information. They do not test drive anything before reporting.

    berreez wrote:
    When you divide the wheelbase by the length of the motor home, you should have a wheelbase-to-length ratio of 53%. This ratio gives us a good idea of the handling characteristics you can expect from this vehicle.

    From the above statement, is it better to have a number lower or higher than 53% if you what better handling?
  • Wheelbase to length ratio has more of an effect on ride than on handling. Plain old wheelbase has more of an effect on handling. A long wheelbase will make the vehicle more stable but will make it harder to handle in tight turns, like in a city or getting into a camp-site. The long wheel base makes the rear wheels track farther inside of the front wheels, and usually ends up with a larger turning radius. From a ride perspective a long wheelbase to length ratio puts the rear wheels farther back and the front wheels farther forward and the vehicle tends to ride more smoothly. A short wheelbase to length ratio puts the rear wheels farther forward and you tend to get a rocking-chair effect that can be quite dramatic at the very back of the vehicle. Pusher Class A-s usually have the longer wheelbase and wheelbase to length ratio and are known for a smoother ride. Front engine Class A's are the ones that often have a long overhang behind the rear axle, might handle better in tight quarters, are a little less stable on the highway and tend to ride choppier, particularly for passengers who might be at the back of the bus...

    Brian