Thanks John, I have managed to get a tire tread drawn, but I don't think I followed your instructions right, or maybe I did?
I laid out the rectangle, made it into a shallow box and removed the lattice work to leave the treads. I did this using 3D boxes rather than polylines. Then I tried to bend the whole thing, which didn't work.
Then I looked at your original drawings and saw you had only selected one 'row' of treads to copy. This led to some huge rings created until I realised I had to set the tread on the edge of the cylinder, and count the number of sets needed from the layout. Then I kept changing the +Rot to '0', which I worked out was the wrong thing to do.
I have produced the attached, but at present each tread is a separate solid and I'm not sure how to make it once piece without individually adding them, so need to work out some more things.
Thanks again for your help.