After some use I learned that the main rails were flexing under load and I wanted a proper carry box as well – one that was watertight and strong . The case I found is one of those sold for camera equipment and has a very good seal around it. It also has holes in it where you can put a padlock.
I then added some aluminium rail brackets underneath so that it slides onto the rails on the carrier.
The carrier needed to be remade to fit the case and when I did I added some reinforcing bars to stiffen it too. I also added a lock so that the case can be locked onto the bike.
I am now very happy with it, and the bike in general. I ride it to work every day and take it on long rides when the weather is good on weekends.
The last thing I have to do now is to make the bike rust proofed. Some of the nuts and bolts have surface rust on them due to a lot of rain lately so I am replacing them with stainless steel bolts where possible and I have some special paint to deal with other parts.
