The FWS1000 used 41.3mm Showa forks. They’re a distinctive looking fork due to the external fluid tubes, adjustments and anti-dive features etc.
The regulations for the racing class we’re entering requires that the forks be no bigger than 41mm in diameter and that the external appearance of the forks are to be visually comaptible with the era represented however, internal modifications are free. The original Showas are not the type of part you can find at swap meets or on eBay so we had to find a way of making a set of forks that looked somewhat similar. After some searching we settled on the Goldwing GL1500 fork. They were 41mm and the bottom sliders featured similar mounting lugs for the anti-dive layout. The tubes on the GL1500 are waisted near the top triple clamp area which is unsuitable for the clip-on handlebars we ‘re using so we adapted CBR600F2 tubes for that role.
Due to the hybrid nature of these forks there are no aftermarket cartridge solutions available so we had to design our own cartridges using Ohlins NIX22 pistons. While we were at it we also incorporated a top out spring system. The cartridge tubes, damper and adjustment rods, needles, piston holders, fork caps and preload adjusters were all custom made to adapt to the Goldwing fork bottoms, CBR600F2 tubes and Ohlins NIX22 pistons. A special shout out goes to Laurie Smith from Suspension Smith https://www.facebook.com/Suspensionsmith for shimming and valving the forks.
For the rear we used a remote reservoir Ohlins shock absorber specified for a Honda CBR600F2 because the rear suspension has a similar motion ratio and travel. Final choice of spring and valving will have to be evaluated on the track. A longer lower extension was fabricated to enable the shock to fit through the rear swingarm.