Evolution: Suspension, Part 1

I guess in order to have true knowledge of where you’re going it would be best to really know where you’ve been. As it sits on the showroom floor the stock Sach’s suspension on the S1000RR is damn good. The components inside the forks are stout, high quality, and purposefully engineered. The shock also had great build quality along with supple characteristics when we rode it for the first time. It would only seem logical then for you to ask, why in the world would we bother going to an aftermarket suspension? Well I’ll tell you.

In the world of motorcycle road racing time is always in short supply. Every new race weekend seems to come up almost immediately after the previous, and every new track presents different challenges. For these reasons a successful race team needs to be highly adaptable, so much so that it is actually the main reason we’ve started with the Ohlins suspension components on both Gary’s and Jeremy’s bikes. A set of 30mm fork cartridges for the front and the latest TTX shock for the rear went in each bike. The Ohlins Company has been around for so long, and has so much data that is made the adaptability we needed possible with hundreds of available spring rates, an almost infinite number of shim stack possibilities, and quick ride height adjustment capability.

At our first official test with the bike at Buttonwillow Raceway Park we had the suspension adjustability we needed, but found a little something missing in the process. In the current world of sportbikes there is one five letter word that can cause more raised eyebrows and confusion amongst new riders than any other, TRAIL. What does it do? How do you measure it? Do I have too much, too little? Addressing all these points would be another installment by itself for now I can just refer you to an informative Wiki piece I found some time ago (http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_geometry). To make a long story short we’ve found that the S1000RR has a relatively large offset (approx. 32mm) leaving a small trail number. At Buttonwillow this was causing certain feel issues that needed to be addressed. Thanks to Attack Performance we were able to do just that. Being able to adjust offset/trail Jeremy was able to get the feel he needed to push the bike to lap record pace.

You’d have to say in our first race weekend with the bike we found a great setup. After all, the first race lap he turned on the thing was a lap record, but in fact everything wasn’t great. For starters the bike was giving the rider great feel, but it was only when he was on the suspensions limit (in the bottom of the stroke where the fork can be very abrupt). I don’t know a rider out there that wants to ride every lap of a race having to wonder which side of the fine line they’re on. Secondly the shock displayed some undesirable characteristics. Much in the same way that a fork has the compression and rebound damping tied together by design; this TTX was acting the same way. However, the whole design background of the TTX is to eliminate this dependency. This along with the shock’s lack of consistency over race distance was no good. Damping was strong for the first 2-3 laps, but past that point the rear tire control was dropping with every corner. Our goal for this project is to go racing in the AMA, so this problem will have to be dealt with one way or another. In our commitment to development on this bike we wanted to see if there was something better. Is there something out there that would give us the same feel with a better safety margin? Is there something out there that could give Jeremy better feel? Yes, yes there is… (to be continued)