Closest thing I can see on the Technobots website is this:

http://www.technobotsonline.com/banebot ... -bore.html

In new money, the 1/2 bore is 12.7mm. The shaft of a GR02 is 12mm so that may be a bit too small; the adapter could rock a little, resulting in loosening grub screws and wheels falling off. Then again, it could be okay, could be worth buying them to try, although at £8.65 each it's not the cheapest might-not-work experiment.