Discussion of motorcycle and related vehicle noise issues, especially related to aftermarket modification (non-original replacement exhaust silencer systems (NORESS)).

Presentation on the status of the European Commission-sponsored study to investigate the potential of and develop a proposal for new sound limits of L-category vehicles under Euro 5.

German authorities have carried out a study to assess the possibility for measuring UN R41.04-approved L category vehicles using typical “roadside check” equipment. The study found that such equipment provides a “lite” version of the UN 41.04 procedures that is useful in evaluating real-world performance. Germany intends to pursue a national “pass-by lite” test directive for UN R41-approved motorbikes and for non-original replacement exhaust silencer systems (NORESS) roadside and periodic technical inspections.