Druid cut some bike tubing about 40mm long and tie them on with that, works a treat, I use it for tying all sorts of gear on my side rails. You can tie the rods to the top or the sides of the rails. When you cut the tubing cut it down the centre so you will get two pieces. Wrap it around a few times and then past the end under the last wrap it will hold on tight as. Cheers Charlie.