That's pretty cool. How hard do you think its going to be to remove the stabilizer from the seat. I realize this is going to happen once before your trip and once after it but its a design point worth considering for anyone else to try it. It looks like the original uses a threaded aluminum piece but the cost of a tap makes that cost prohibitive.
Nice job.
Thanks. It takes about 5 minutes to fit it. I agree that a solution that is quicker to fit would be better, but I just used readily available items from ebay. Mainly to save expense on and specialist tools. The bracket works a treat and has really made the pack stable and makes fitting the pack really easy.
If I had the tooling you could use a metal bar which has been tapped instead of the p-clips to secure the bracket to the rails.