OK, from Transport SA's website:
The holder of any class of Driver's Licence is authorised to ride a
'moped' (provided the moped is compliant with the Australian Design
Rules and is registered and insured). A 'moped' is defined as a two or
three-wheeled motor vehicle (other than a power-assisted pedal cycle)
that:
- Is propelled by an
internal combustion engine with a capacity not exceeding 50
millilitres; or a motor other than an internal combustion engine; and
- Is capable of a speed not exceeding 50 kilometres per hour.
The holder of a learner's permit cannot ride a 'moped' on the learner's permit, unless the permit is for class R-DATE or R.
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So you need to have a Driver's Licence for a car (not a Learner's Permit)
to ride a 50cc scooter, so you will have to go through all the tests,
training and what-have-you to pass your Ls for cars first and be on
your P plate first.
If you are just interested in getting on two wheels then the fastest way is to get your motorcycle licence properly.
http://www.transport.sa.gov.au/licences_certification/motorbike/index.asp
Transport SA:
Freecall 1800 018 300 between 8.30am and 5pm Monday to Friday.