This is something that probably isn't discussed a lot in most Trike forums or motorcycle forums.
However, running ole VDub equipment with flat tappet engines one must have a concern with this subject.
Something that made me very aware of this is that Engle Racing Cams WILL NOT warranty their camshafts unless you can prove that your running an oil that has at least 1100 PPM ZDDP in the oil. Now that must either be the oil that you use or an additive to the used oil.
After doing a bit of research it is pretty tough to come up with a solid conclusion as to what oil actually has the proper amount of ZDDP in it.
For those that don't know what ZDDP stands for, it is; Zinc dialkyldithiophosphates
Its basically an oil detergent that helps with metal to metal wear.
I have not really found conclusive evidence on what oils have the needed ZDDP and what oils do not.
Many claim that the Mobile 1 full synthetic oils contain around 1300 PPM but nothing is conclusive. I used Castrol GTX 20w-50 for years in VDub engines in the past with great results and have emailed Castrol on their detergent content but haven't heard anything back from them as of this posting.
At any rate, I am curious as to what other VDub trike owners are using and if you have found solid evidence of oils containing the recommended amounts of ZDDP?