As long as it's a dedicated motorcycle oil ... take your pick. Just make sure that it's not for cars as this will cause the clutch to slip (allegedly). I've used all sorts in my Daytona 955i and the Trident 900 with no problems. Daytona has now gone to pastures new, but the Trident got some of Halfords 5w/40 (not for the first time!) when I laid it up for winter (5 litres for less than the price of 4 litres of many others!). I have heard that mixing brands is not to be recommended, but people tell me owt ... and I believe them!!
The Triumph recommendation for their new bikes is Castrol Power 1. As previously said don't use car engine oil as it can cause clutch slip problems.
I went for the Silkolene Super 4 and K&N filter combo from M&P for £30.99 delivered. Thanks for advice chaps. Nigel
"Nowt"......Steve, I love that word and as a southern softie, I have stolen it and use it daily and I don't care!
You are very welcome, Nigel, though it may cost you a pint should our paths ever cross!! You see, it is true ... there's good in everyone!!