(15 Dec 2016, 4:01 pm)G-CPTN wrote Not all B9TLs on the TEN have the so aptly described noise - though most of them do.
(6073 was the quiet one today.)
I wonder what has deteriorated to induce this grunting noise, as I don't recall it being a feature when they were new.
Pretty sure it was present from new on the X1 branded vehicles - includng the second batch.
I can't remember the noise situation on the other Gemini vehicles, although I have yet to ride any Percy Main or Stanley examples.
However, I am sure the newer builds don't have opening windows at the front (may be wrong on that). Whether it makes much difference, I don't know.