Racer 450 met up with Wayne Mooradian of PEP (Performance Engineered Products) after the second moto in Red Bud. Wayne’s primary rider Tim Farr had just placed a second overall finish and the Baldwin/PEP/Honda camp was in good spirits. Wayne shared some ATV racing and suspension history with us and told us how the most revolutionary ATV racing suspension came to be.

So Wayne, when did the first ZPS (Zero Preload System) shock come about?
The development started in 92’ when I was working with Gary Denton in the Stadium Series. I liked the idea of the Stadium trucks setting low while maintaining full suspension travel. The problem was, they ran sway bars front and rear to reduce roll but we couldn’t really do that with an ATV because you set on top of it, not in it like a truck.

But I looked at the concept and I took some dampening characteristics and started playing with them. I found that they needed different characteristics for the rebound and compression. The spring rates had to vary as well.

In 93’ we ran them in the desert at a few events with good results. In 94’ I sponsored Mike Erhardt and he wanted a ZPS style shock. I said, well, we’ve already been working on it for a desert application but not for a motocross application.

We built a large body shock for a bike in 94’ and zero preloaded it front and back, it worked awesome. In 95’ we built some more test bikes with some small body stuff and came up with a set of shocks that weighed just over 15 pounds, which was unheard of at the time. By 96’ we had the shocks set up like we wanted them.

I talked to a rider from New Zealand that was here in the states riding, he was that National Champion back home, and I made him as offer to do some R&D work. I said; if you want to come back here and race the 96’ season of MX and TT I’ll build two bikes and pay your way, but you have to do both. I had some other riders but they were racing for the championship so I didn’t want to use them for development.

At the first TT National, he won. Then all the other riders said, hey, whatever he’s got, it works. We’ve got to have it. He went through the rest of the season that year with no problems and it worked out great. At the end of 96’ we made them available as a 97’ model.

How many changes have the shocks undergone since then? I know everyone seems to be going for the new 8 clickers now.
The original was like that but my riders wanted more adjustment so we went to the 20 click system. About 2001 everyone started saying, we need to be able to set things up quicker. They kind of liked the 8 click like the older shocks had. I said “What the Hell” (laughs) I give you this and now you’re telling me you want to go back to the old setup.

One of my riders, Tim, had some of the old shocks left from like 95’. He said, we’ll just put these on my bike, we can find out were we need to be a lot faster. So what happened was, we ended up taking his old shocks and using them on the 02’ bike but with new refinements like larger bodies and a different valve kit. It advanced from there.