The group caught up to me at the next lights. I was surprised to have one of the cyclists demand that I wind down my window and announce in an outraged tone that 'it is legal to travel two abreast'. Although I thought this was counter-intuitive, I made it my business to check whether this claim was correct (maybe the club cyclist was correct and I was wrong, despite the attitude).
However, I found this booklet online http://www.sa.gov.au/__data/assets/pdf_file/0020/23438/DPTI-Cycling-the-Law-Booklet.pdfhttp://www.sa.gov.au/__data/assets/pdf_file/0020/23438/DPTI-Cycling-the-Law-Booklet.pdf
At the top of page 13 it states:
Where there is insufﬁcient room for two riders to ride abreast
in a bicycle lane, you must ride in single ﬁle. During the bicycle
lane operating times, you must not ride outside a bicycle lane
abreast of another rider unless you are overtaking.
I was relieved to find that I was correct, but disappointed that a club cyclist was ignorant of this piece of common sense. I guess it is a case of rule 151 (two abreast allowed) being trumped by rule 247 (stay within bike lane).
I've taken the opportunity to post here in the interests of educating cyclists that may otherwise think two abreast in a narrow bike lane is a safe option! (Obviously, if there were no bike lane then cyclists can legally and readily fit within a typical motoring lane.)
I guess most riders are more sensible and have a better sense of self preservation.