The Knudsens use the Quad-Rops on their property in a little place known as Matingarahi on the Firth of Thames.
They say it gives them peace of mind, creates a real sense of safety and enhances the day-to-day use of the quad.
"Being a user it made me the ideal person to design it," Knudsen says.
"Very little agricultural plant is designed by the end-user."
He looked at other protection systems on the market and saw they offered little or no safety zone for the rider and did not prevent the quad from rolling down the hill and being destroyed.
So he set about coming up with a better design.
The Quad-Rops is a frame that can be mounted to almost any make and model of quad bike and includes protection above the head.
It allows great visibility and doesn't interfere with the use of front or rear carriers.
As well as rollover protection, the Quad-Rops protects the rider against injury from unseen wires, branches or other obstacles.
Knudsen says he has tested the design in front, backward and sideways rollovers and the frame gives excellent protection and minimises damage to the bike.
The single overhead bar design protects the rider and greatly reduces the possibility of being pinned down by the bike.
As well, the angled top struts help slow or stop the bike from rolling excessively.
There are added benefits with the frame, such as being able to mount safety lights, mirrors, a windscreen and even a flexible sunshade.
Although there is a lot of negative talk at the moment about quad bikes -- but very little from people who actually use them) -- compared with other utility farm vehicles, Knudsen says the reality is that farmers won't be changing any time soon. He says there are thousands of quad bikes in use, with a huge array of purpose-built accessories, and farmers have come to appreciate how versatile, reliable and affordable they are.
"The only real issue is safety and I believe I have a practical answer: retrofitting the Quad-Rops to your existing quad."
There was considerable interest in the design at Fieldays where people could see the common sense in the design.
Next step for the Quad-Rops is to start manufacturing the product and selling it direct.
"I'm not a fan of having a middleman," Knudsen says.
"I like keeping it simple which also makes it more affordable.
"Having been a manufacturer before I have the knowhow and ability to make a quality product.
"I'm really pleased with the Quad-Rops and I know it will save lives."
* To find out more about Quad-Rops contact the inventor on (09) 2922142.
