Oils-the old chestnut!

[stu.andrews]

I have recently purchased a 1966 Triumph TR 6 in very good condition. Upon reading different publications I find that different oil recommendations are used. I have heard that multigrade oil is not the best for a classic, due to holding particles in suspension & also not to use any semi or fully synthetic oil in an engine with roller bearings. The gearbox oil recommended varies from SAE 50 to an EP 90 (I know that the viscosities are virtually identical) but which is the best?
Your advice & experience would be very welcome.

[TBS]

I use Silkolene Chatsworth 40 in the engine and a straight 90wt oil in the gearbox.

[Trumper]

  Hello,nice bike ,very shiny,where's the oil  
  I asked the same question on here a while ago,hope these help you
http://www.vintagebike.co.uk/cgi-bin/yabb2/YaBB.pl?num=1221219121/6#6
I use ep 90 in the gear box,straight 30 fuch[sp] i believe in the primary chaincase i still have the straight 40 for the engine although it will be a while before it needs changing,having said that I've managed about 60 miles on it this week

[stu.andrews]

Thank you Trumper & TBS for your help.
Must admit that the last Triumph I had was a 1958 3TA in the 60's & that was an absolute heap of c***. Looking forward to getting some riding in.