air bags on truck
We were told that by adding air bags to our truck we could pull a 5th wheel that is heavier than the manufacturers recommendations. Does anyone know about this? We have been told by more than one RV d...
Forum Discussion
mdamerell wrote:Me Again wrote:
20k is an axle with four tires. An axle with two tires is 12k or the tread width depending on state etc. Tandem axles (8 tires) are 34k.
Most standard 18 wheelers are 12+34+34=80k
Chris
Not true, depends on tire and axle rating. My Steer axle was rate at 14,000# and I ran J(? it's been a while) rated tires to support that. My drive axles were actually rated for 40,000# but limited by bridge law to 34,000#. Still maxed out at 80,000# but gave some wiggle room to scale it out. The super singles are an example of 2 tires on an axle rated for 20,000#
Bridge Law to protect road and bridge surface. Also controls distance between axle sets.
Single axle 20,000# (based on axle and tire rating but 20,000#)
tandem axle 34,000#
spread axle 40,000# (think it was 8' center to center of the two axles)
Close on the spread axles. It is a 10 foot spread to carry 40,000.
