Hi Rushjob,
very comprehensive reply
yes, I did realise that they are not type approved to retrofit, my point was though that the sweeping statement of being illegal on bikes is no longer true, given that new bikes come with them fitted now.
Its also interesting to note the 'do nothing but advise' by the MoT tester. This implies that the vehicle will not fail a test as long as they are correctly adjusted. This is my experience.