hello s is for a bmw r45 but i think all the R's are the same and maybe the K's if not i can do any shape/size, i made one of these a while back in 25mm tube 2mm wall but also available in 22mm 2mm wall and  never listed it,,i've had loads of interest in bmw's since  so i'll add the drawings to give you a idea and update the photos as i go,if your interested just get in touch 
thanks,,shaun                                                                                                                                                                                                                                      07706437408
                                                                      shumph@live.co.uk