From the work and test done by MXA, it was obvious that suspension and shock were a part of the important features that make a bike shine. Unfortunately, not everyone realizes it until XMA decided to build the replica of Dean Wilson’s Yamaha YZ450F.
The mission was to build a replica that looks and also functions as close as possible with the real thing so improvements and creative work had been done to it. Set for the issue for August 2017, it was like a sole mission to come true.
Everything started off good, especially when Mitch Payton gave the legendary YZ450F engine, specifically tweaked for Dean. And then everyone was contributing to the work. Split Designs sent the graphics for Dean’ bike, Dubya sent out the kite wheels which were pretty identical, and then ARC sent out the levers. Again, those are the things that either is found on Dean’s bike or being used by the rider.
As if it weren’t enough, Cycra sent out the plastic, VP gave the fuel, Moto Seat was giving the saddle, and Galfer provided the rotors. But the star of the show was actually the Kayaba working suspension. The AOSS Factory Kayaba spring forks alone cost around $4500; not to mention the triple clamps Xtrig ROCS (costs $900) to mount everything to the bike. And it wasn’t included the Kayaba working shock. It went without saying that it was one costly project – and a difficult one too.
It was a good thing that Bones Bacon, the Pro Circuit expert, to help with the job. He re-valved the Yamaha stock SSS Kayaba shocks and also forks as the alternative way, in the event that tracking down the working suspension would be difficult. But as if it were destined to complete successfully, the project got another help from Technical Touch, which happened to be the supplier for Kayaba parts. They provided the Factory AOSS kit shock, fork, and also triple Xtrig clamps so the project could complete. But as the result, the re-valved suspension from Bones was set aside and then forgotten.
But then again, the test was over with disappointed riders. The borrowed working suspension was returned, and the modified SSS Kayaba suspension belonged to Bones was returned to the bike. The disappointing test happened because the riders sucked while the suspension was doing great. It is the suspension that most teams dream of having. Being the best rated product OEM suspension for 11 years has proven it all.
The SSS Kayaba spring fork exceeded everything, delivering the best outcome for all kinds of track layouts, skill levels, and different kinds of riders. But Bones had promised that he could tweak the SSS components, making them as good as the AOSS Factory Kayaba spring kit fork, without the metallurgy and exotic coatings, of course.
And as everything turned out, the tweaked components were impressive. The modification turned out to be successful. Bones replaced the stock fork springs with 0.51 kg/mm parts with the heavier 5.2 kg/mm ones. And then he also installed the National spring tubes from Pro Circuit. The aluminum tubes were able to control the flow of the oil as well as replacing the stock plastic parts.
Bones was focusing on the fork compression stack with the purpose of keeping the position of the fork higher in the stroke. It was meant to reduce or remove the mid-stroke spike. The result was apparent with great tracked performance from SSS forks, able to absorb the bumps without shaking.
The cost for the re-valve work is also lower when compared to the real thing. With complete components, such as oil seals, shock, dust seals, fluids, fork, and fork bushings, everything was ‘only’ $1375.