Author Topic: What? No oil discussion yet...  (Read 4039 times)

Online groily

  • Wise & Enlightened
  • *
  • Join Date: Jul 2007
  • Posts: 1322
  • Karma: 24
Re: What? No oil discussion yet...
« Reply #15 on: 25.12. 2007 21:39 »
I'm sure it's good oil old PJ, and probably better than most monogrades. Had multigrades existed when our bikes were built, quid to a pinch of **** it would have been recommended. Yes, it's runnier when cold, and there is the risk of slightly more leakage. However, for 30 years I've been using any branded 20/50 in all bikes with shell big ends. If I had a single with a roller big end I might go the mono route. I also use 20/50 in a pre-war car with white metal mains and ends and have for nearly 20 years. You WANT the oil to be thin when cold on start up so it flows . . . The only time I wouldn't would be if a motor had been run on mono for ages and hadn't been stripped and cleaned, for fear that the detergent elements in the multigrade might dislodge muck in the oilways. I think, personally, we are too often blinded by myth and less susceptible than we should be to reason. A decent multigrade can easily cope with roller and ball bearings and bushings too - heck, it was recommended lube for many a gearbox for years - and so I'm sticking with it. Far cheaper too when it comes to the regular changes we tend to go for - 1000-1500 miles is pretty much par for the course.
Finally, in some more recent cars (1960s) in my tatty pile of stuff that runs, I run them in on 20/50 and then switch to  semi-synthetic Castrol 10/60 from Castrol Classic Oils - pricey - but I only change it thereafter at 5000 miles, as the stuff doesn't degrade like non-synthetic oils owing to the long-chain polymers and all that - so it ends up cheaper. A chap I know who used to be head chemist at one of the big oil companies told me that an oil like the 10/60 would be in a better state after 5000 miles than any non-synthetic after 1000. I believe him, and so far so good! Groily

Offline Pim

  • A's Good Friend
  • ***
  • Join Date: Sep 2007
  • Posts: 59
  • Karma: 1
  • Enschede - The Netherlands
Re: What? No oil discussion yet...
« Reply #16 on: 29.12. 2007 13:02 »

Great info! very usefull, there is one thing though. can some one tell me what this 'breather' is everyone is talking about? and can anyone confirm that the little outlet in the top of my oiltank is a pressure relief outlet? that's what seems most logical:) but i'm not sure.

sorry for all the questions and little input, i'm trying to learn as much about anything so this won't be the last one:)
Thank you! Pim.
Slow but steady...

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5589
  • Karma: 52
Re: What? No oil discussion yet...
« Reply #17 on: 29.12. 2007 15:13 »

I want to respond to the breather question, but I will do it at:

This is a long thread on that topic. My response is currently at, or near, the end of page 2.


Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at for details.