One of the tenets of why the backstory matters is because we dont have enough data to help you. As others have posted, its important to not have to cover ground without the baseline facts.
Myself?? I dont trust others work except a select few. Any new machine to me, recently rebuilt or barn fresh is suspect as its simply a guessing game of what might have been done by the DPO (Dreaded Previous Owner)
For example, wheel bearings, often overlooked and usually neglected, cheap insurance and always a good idea on a unknown machine to clean, inspect and service them, and in cases where possible, just upgrade them with new modern sealed units. (On many Triumphs I can purchase the bearings in bulk/case price for $6.00 USD each which is certainly a bargain to keep me from going SPLAT!).
However your issues are situational. WHERE are you? Because what works for me up in the woods of the US Pacific NW does not apply to for example,, there is a fellow on here with a very nice A10 we just learned about him riding in the DGR of the wilds of Kenya Africa (Great post BTW, really enjoyed that!)
Lastly?? My votes is a good service and if possible, a good quality modern oil (Assuming the sludge trap is in good nick) with a quality filter, a good climbing gear modern gear oil and a DRY primary with a belt drive, failing that using Type F Auto trans fluid.
Oil is a debate and shifting paradigm and some people are known to argue hotly about. On the old Brit-iron forum oil wars percolated for years. What I *THOUGHT* about oils is outdated and I learned a lot from some recent testing.
This link leads to outstanding work and while Not-Run orientated is close enough. The guy who wrote and did the work was very thorough. I dont always agree with him but nothing but respect for the work and effort he invested in this endeavor.
See:
https://www.accessnorton.com/Oil-Tests/NortonOil.php**Note; One of the list members was making inquiries with a oil company on specs and details related to vintage bikes and the tech rep he spoke to referred him back to this topic! So even oil companies are paying attention!
Here in the US it is getting challenging to find suitable lubricants for our vintage machinery. Go back and do your intro, and happy to help otherwise.
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A big THANKS to Jim Comstock for evaluating oils that will work best in our Norton Commandos! Jim has spent a lot of time testing these oils. Click here to visit the Access Norton "Oil Tests" thread.
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The oil testing is done with a set load at 220 degrees for the first 30 minutes. This stresses the oil under high shear conditions and gives a good indication of the heat produced by friction.
Then the oil temp is raised to 320 degrees and the load is increased until a scar is produced on the follower. The test stops at this point and data is collected.
The red trace is follower pressure.
The black trace is follower temperature. The difference between the follower temp and the target oil temp is a good indication of heat from friction.
The green trace is friction.
The violet trace is cooling fan cycles. When it is high, the fan is on and it shows oil temp. When it is low then the oil is at the target temperature.
For use in a moderately tuned street performance Norton I would suggest a minimum load capacity of 150 lbs. Low friction is a plus, particularly in warm climates.
Heat from friction is on a 0 to 10 scale. The lower the number -the better the result.
A detailed description of what Total Heat from Friction is, how it is derived and that lower values are desired:
The term total heat from friction refers to a unitless value that describes the overall heat generated during an oil test and is derived using the following inputs:
1) follower temperature.
2) oil temperature.
3) cooling fan run time.
Separate calculations are performed to characterize:
1) heat generated during the steady-state phase of the test, i.e., from 10-25 minute run time with fixed load, and referred to as heat from viscous friction
2) heat generated during the latter phase of the test, i.e., as load increases continually from 30 minutes to test conclusion, and is referred to as heat from high pressure shear.
These 2 separate values are then weighted appropriately and combined to obtain the total heat from friction value.
Lower total heat from friction values are desirable and will make for a cooler operating engine.
The high heat from friction oils would be best used in moderate or cool climates.
There are a few ways to browse the Norton Commando Oil data. The same data is available in each section, but laid out differently and more detailed in some areas. (Please note this page is not designed for mobile devices).