Lower ROPS

MHarryE · May 17, 2012

Many years ago Mercedes had a pop-up roll bar on their convertibles. Sensors and a computer predicted an impending rollover and I believe it flipped into place in 0.3 seconds. Not sure if they still do that. But having attended at least one ROPS test, I remember the testing company placing something calle a - if I remember correctly - a displacement limiting volume - in the operator position. Through the various loadings nothing could intrude on this volume, simulating an operator. I believe the test manager said this represented a 90th percentile operator. So if you are the 50th percentile operator you have a pretty good margin of safety. But in an accident a person moves more than one might expect. I was once in severe turbulence where after things settled down a very concerned flight attendant who had been sitting behind me asked me if I hurt my head or neck when I hit the overhead. I had my belt tightened as tight as I could, and I am about the 50th percentile person, yet the belt and my body stretched out so much in the turbulence it appeared I hit the overhead which was a long way from my head when I was seated. The plane was a lightly loaded (4 passengers in a 50 passenger plane) turboprop and the turbulence was enough to empty most of the seat pockets of their magazines so it was a good jolt, well over 1G, but probably less than in a rollover.

horse7 · May 20, 2012

Current production Audi cabriolets (at least some of them) have pop up roll protection. Much better appearance then the old style fixed bars.

The reliability engineering would be interesting, tractors continue working for several decades unlike the fleeting lifespan of the typical "replace it in 5" automobile (admittedly it seems like they get about 20 in the NE US before something critical rusts and can't be reliably fixed. Much longer in California).

scrappy isb67 · May 20, 2012

I usually leave my ROPS down like is said here before. when I am in a situation that warrants it, I put it up and almost every time I do, I hit the garage door header when it is time to put the tractor away! I am GOING to break something! my ROPS when is up is a FOOT at least higher than my head !The hinge for the ROPS is shoulder high! and the upper hoop is another ~2' on top of that! And the same ROPS is used on ALL 2000 series JD CUTS. so it is too tall and overbuilt for my smallest/lightest of the 2000 series 2320.
I could buy the upper hoop and have it cut down 6" and still would have LOTS of headroom! or buy the whole upper structure and cut down the posts 3" and the hoop 3", The second option would be best since I too have trees to mow around and even folded still hit!

ray66v · May 20, 2012

scrappy isb67 said:
I usually leave my ROPS down like is said here before. when I am in a situation that warrants it, I put it up and almost every time I do, I hit the garage door header when it is time to put the tractor away! I am GOING to break something! my ROPS when is up is a FOOT at least higher than my head !The hinge for the ROPS is shoulder high! and the upper hoop is another ~2' on top of that! And the same ROPS is used on ALL 2000 series JD CUTS. so it is too tall and overbuilt for my smallest/lightest of the 2000 series 2320.
I could buy the upper hoop and have it cut down 6" and still would have LOTS of headroom! or buy the whole upper structure and cut down the posts 3" and the hoop 3", The second option would be best since I too have trees to mow around and even folded still hit!

The regulation requires there to be 30" from the highest point the seat can be adjusted too, to the top of the ROPS.

On some subcompacts, the seat raises up for backhoe operation. This can require the ROPS to seem excessively high during normal tractor operations.

If your ROPS height exceeds the 30", then your right, they did get lazy and do a one size fits all.

xtn · May 20, 2012

Regarding the human body's flexibility: you will stretch and bend much farther than you can possibly imagine with the forces put on you during an accident. Simulating your motion with your own muscles is not going to even be close.

JDgreen227 · May 20, 2012

There is no need to hit your garage door header with your ROPS because you forgot to fold it !!! After you pull the tractor out and raise the ROPS, place a sawhorse, a trash can, a folding chair, etc in front of the door with a sign on them that says "LOWER ROPS". Or do what I do, I have one of those big orange traffic cones that I have painted a big black "LOOK UP" on, and I place that in front of the door.

RoyJackson · May 20, 2012

JDgreen227 said:
There is no need to hit your garage door header with your ROPS because you forgot to fold it !!! After you pull the tractor out and raise the ROPS, place a sawhorse, a trash can, a folding chair, etc in front of the door with a sign on them that says "LOWER ROPS". Or do what I do, I have one of those big orange traffic cones that I have painted a big black "LOOK UP" on, and I place that in front of the door.

That's a good idea...