I recently received a Sir Tech inquiry from a Harley-Davidson owner who was considering using a Bel-Ray Full Synthetic Ester 10W-50 engine oil. The customer was told by a mechanic that synthetics are too slick to allow bearings to roll, that they just turn on one spot and slide within the race.
I told him “you are another victim of synthetic oil lies and so is your H-D mechanic”… He probably heard it from someone he thought knew about lubricants and he has been spreading these lies unknowingly to customers like you. I dare you to contact someone at the H-D Motor Company and have them verify for you the roller bearing bull or that you will void your warranty if you don’t use H-D oil. It won’t happen. The roller bearing myth is simply not true. When we heard it our chemists and engineers laughed for over a week, but we still did testing to prove it wrong. We even had an outside company test it and found that synthetic oil will not cause roller bearings to slip, spin or do anything they weren’t designed to do. Using a Bel-Ray Full Synthetic Ester motor oil will not void your factory warranty. This is another common myth that is widespread to put fear into H-D owners like you.
Following are several reasons why we recommend Bel-Ray V-Twin Synthetic Motor Oil 10W-50 for H-D and other air-cooled V-Twin motorcycles.
One other thing I love is the one about H-D engines being different… what are they using, nuclear power? Do they have emendator shafts? No, they are internal combustion, air-cooled engines that use metal, gaskets and ‘O’rings to get the result of power, hence locomotion. Yes, the design is unique, but it isn’t that different!
I apologize for my over-zealousness but this H-D myth stuff really chaps my hide.
Good luck riding and enjoy your bike,