Hiya Daffyd
DON'T GET ME STARTED ON FRONT DISCS !!!

A long and boring story reduced to a short and boring story:
I had four new discs and two replacement callipers!!!
In the end, I called the dealer who contacted Triumph warranty department thingy.
They 'sort of' admited a problem and were waiting for a machine to come up and have it back to test.
My discs were going (what seemed like!) every other week so it was only a matter of time before my bike flagged up again.
They had the bike back for what turned out to be around 5 weeks while I was in Arizona in Jan/Feb this year.
They apparently had the bike on all sorts of jigs and rigs - tested forks, alignments, wheel trueness, hub trueness ... they supposidly had the wheel apart and tested the tollerence of EACH SPOKE!! - if you can believe that!!
The long and short of it was they found NOTHING!
They put a new front wheel in and sent it back.
Now, touch wood (and if it goes now, I'll kick someones a$$!) it has been OK.
Based on previous failures, it should have 'gone' a couple of thousand miles ago!!
Good luck getting it sorted - I told my dealer in no uncertain terms that if it keeps going after the warranty runs out, I'll not buy the Triumph disc : not while I've got an hole in my arse!!!