DRIVING CORRUGATED ROADS
WHAT SPEED? WHAT TYRE PRESSURE
http://www.yourtripright.com/driving-corrugated-roads.html
(Brett Toll)
All people have set assumptions in all areas of life. I like to test my assumptions as often as I
can.
Jess and I have been living on these roads for years and whilst we think we know how to best
handle the conditions all we have is a bit of hear-say and opinions. Not really what I should be
basing my opinions on.
How to handle the corrugations is a topic that comes up between locals every fortnight and
when tourist season is here, every tourist gets told 100 different things. So to help you out on
your next trip I put some science into my theory so you know exactly what you’re talking about
when it comes to corrugations.
Leading into the test I believed that lower tyre pressure and high speed was the cure to the
vibration of the corrugation. My theory was "you are going so fast you only hit the top of the
corrugation, not the whole thing". I estimate 85% of my bush friends will tell you the same
thing. We are wrong.
In general this is how my set up of corrugations looked.
General speed: 95km-80km
Rear Tyres: 32 PSI
Front Tyres: 28 PSI
About the test:
I wanted to do the test in conditions similar to what most tourists experience in the tourist
season so I was waiting a long time for a day that stayed below 35 deg in January. I headed out
of Docker River to a notorious patch of corrugations 15km from Docker River, definitely up
there with the worst on the road. I picked a section that I would do my test on. I started with
my tyre pressures at 40PSI I then tested the pressure at 100km, 80km, and 60km. I completed
the test reducing tyre pressure by 5PSI until I got to 20 PSI. I then measured the vibration in the
car with a vibration monitor. After each round of testing I let the car sit for 15min to allow the
shock absorbers a decent amount of time to recover.
Let’s get into it. The first picture I’m going to show you is what driving on the tar looks like
inside the Prado. You may even be able to spot where I have gone over a speed hump.