Dear Mr T !!!Thanks for your reply. I would be interested in system.There was one on a cb900f when I bought it ,I took it off because the down pipes were tatty .Sounded sweet but was road legal.Downside is ( loss of centre stand and restricted oil filter access) Please let me know if and when and how much .I shall keep an eye on your posts. Ny mobile phone is 07891 091371.Regards Malcolm Avery