[Darren69]

Unfortunately the S4 and S4R are not going to be donors for a speedo drive although the forks are the same so other parts should fit they were always electronic rear wheel speedo drive but maybe ST series would provide the mechanical speedo drive you need or maybe even 748/916/996 as even though the forks are different they didn't change to electronic speedo until much later if ever, and still had 25mm axles too? The front wheels may even be the same. Happy hunting.