Following attempted postings at:
http://www.bigw.com.au/sports-leisure/bikes-accessories/bikes/mountain-b...

I ride approximately 20km per day, to and from work. About half this distance is hills and bends (following a river) and about half is inner urban and mostly flat.

For the past six months I have struggled daily with this bike.

To change gears without the derailleur slipping the upper gears have to turned in the opposite direction to the lower gears. This is not documented in the user and maintenance manual.

The handle-bars fit poorly and a prone to slippage. Ensure that you find an appropriately-sized Allen key and adjust at least every second day. Also, the handle-bars are of a non-standard diameter. You will need some gaffer-tape or similar to fit a light. Due to poor design, the bell is inaccessible unless you take your hands off the grip.

The brakes are also of poor grade and the brake cables will slip with alarming regularity. You will need to readjust these every third day, assuming you're interested in stopping.

By about two months the top gears started to fail as the tension wires simply lost capability. After four months they stopped working altogether. This, of course, had a serious effect on the ability to change gears, leading to the chain to consistently slip off the cassette if one wanted to do something remarkable, like changing gear on a hill. For example, riding to work today the chain slipped off the cassette thirteen times.

This bike is unsafe at any speed.

(Nota bene: This is the third time I have attempted to publish this honest appraisal. If it is rejected again, I will simply circulate it through other means)

EDIT: In response to questions, I paid extra to have this kit put together by BigW staff. Whilst I don't expect too much from a cheap bike or from BigW's bike mechanics, I do expect that the bicycle-shaped object can go from A to B without being a danger to the user.