Active Adventures at Otterspool are hiring out Quadracycles every weekend for the rest of September 2012.
They cost £5 for half an hour or £10 for an hour.
They are advertised as being “a great outdoor activity promoting exercise and health and wellbeing among families”
There seems to be some confusion as to what exactly they are called. Even the poster uses “Quadricycle” but also “Quadrabike”
Wikipedia explains http://en.wikipedia.org/wiki/Quadracycle