Forum Discussion

Chris_F's avatar
Chris_F
Explorer
Aug 08, 2013

Heavier, Longer, and Tighter?

I've read that a longer wheelbase reduces rear swing and improves stability, but increases the turning diameter. Then I looked at the specs for Ford F53 chassis' (https://www.fleet.ford.com/truckbbas/non-html/2013/13_F53_F59_SB.pdf).

According to the numbers in the Steering Specifications, the turning radius does increase as the wheelbase increases within a GVWR class, but the turning radius for a 24,000 lb GVWR chassis with 242" wheelbase actually is tighter than the turning radius for a 22,000 lb GVWR chassis with a 228" wheelbase.

Why?
  • I have also found that if I am turning into or onto a narrow road it is much easier to make that turn be a left hand turn. There is just more room that way.
    Ron
  • I had heard of "wheel cut" and thought that might have something to do with it, but couldn't figure out why it would change based on GVWR and wheelbase.

    The end result for me is that I didn't have a Tiffin Allegro 34 TGA on my short list because of its longer wheelbase. Now that I know it has a tighter turning radius and less tail swing (gas pumps!), it's definitely worth a closer look.
  • It has to do with the "angle of cut" or how far the tires turn.
  • Thank you both for your replies! The specs do show the 24,000 lb chassis front end is wider (the 22,000 lb chassis actually is narrowest of all). Indeed, I am concerned about entering and leaving my campsite, which I have owned and enjoyed for 29 years. There were no problems with a 26' trailer and a 33' park model, but with ditches on either side of the campground road and a narrow driveway, I need to be sure whatever Class A gasser I pick will make it before I buy it!
  • Yes it has to do with the front end and it is probably wider on the higher GVWR chassis, thus can turn sharper, and you get around the corner sooner. Mainly you only turn tightly while parking, or leaving a campsite. Yet be careful when leaving a gas station, you can run the back end into a fuel pump if you try to turn to tight.

    Fred.
  • Probably because of where the wheels are and how sharp they can turn.