Ok one more time. Has it been proven or disproven that certain types of oil (synthetic) more can cause bearings to slide or skid because. Roller bearings or ball bearings included. This is an old Harley shop argument and some Japanese builders say this is an issue as well. Many have run dino or synthetic on all types of bikes and automobiles with no issue but is there any real evidence it is a concern. My recent post in the bike oil forum shows that even Harley Davidson says this is still an issue with some brands of synthetic oil.
Bearings sliding in synthetic oil
- Thread starter hk33ka1
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I heard that as well, but only from Harley. Do all bikes have roller bearings in their build I wonder? I don't know why one synthetic would do it over another as they have similar base oils. Maybe it's the additives that make the difference. I noticed that Harley is marketing their own synthetic oil now, so I guess it works. I found the following links on the subject.
http://www.hdcycles.com/oilfact.htm
[ February 25, 2003, 03:15 PM: Message edited by: BOBISTHEOILGUY ]
http://www.hdcycles.com/oilfact.htm
[ February 25, 2003, 03:15 PM: Message edited by: BOBISTHEOILGUY ]
The synth base oil is not to slippery and causing skiding of the bearings. On the contrary, it's shearing the hydrodynamic process and since it has a lower level of barrier antiwear additives, it has less than adaquate protection, thus allowing the bearings to wear prematurly.
The oils with API rated SH had higher levels of antiwear thus no problem. when the SJ and SL rated oils came out, they have a reduced level of barrier additives due to cat damage in cars. This inturn changed the barrier protection levels and people thing that just because it say's synth on the bottle that it protects better.. WRONG!, A synth oil will provide lubrication longer due to it resisting oxidation of the base oil over a standard mineral oil.
Why do you think Amsoil's oil can run in a bike with out a problem but mobil 1's synth is not used and has been reported to be one of the problem oils for bikes? Because amsoil isn't api certified since they maintain higher levels of barrier additives and mobil has stayed with in the reg's for api certification or sj and sl which demands lower antiwear additives. The difference? both are synth's, but one has higher levels of barrier additives.
This is also true with mineral oils. Get the newer api certified oils, and it will give you the same problems.
Now let me also note here that some of the newer bikes maybe able to use standard motor oils due to the fact that one, it's water cooled, two, they don't share the tran's oil and motor oil together, three, they don't use roller pin bearings such as harley does, so many guys get a way with running conventional due to those reasons. Does that mean you can ? well, if the manufacture specs the oil, you should make sure it does qualify the same or better. In my case, I looked at the gear oil for my evo, sent it in for lab analysis, found it to be a 30wt with certain levels of additives, I then found what oils that schaeffers had that would meet that and more, and been running it since, no problem.
Same with m/c oils, go with what is spec'd or make sure your choice is better either by doing your homework and comparing analysis,(sorry, tech data sheets do not work when comparing these oils as they don't provide you with additive levels used) or you can get with some one like Dyson analysis, and he can help compare oils to ensure you are spec'ing out the right thing. Again, what you'll find, it makes no difference if it's synth or not as for the flat spotting on bearings.
Synth's really shine when you look at all the heat stress a bike can put on a oil, but you must worry first about the wear protection provided by the barrier additives in the oil first to avoid this bearing problem that they all falsly claim to be the synth oil sliding.
The oils with API rated SH had higher levels of antiwear thus no problem. when the SJ and SL rated oils came out, they have a reduced level of barrier additives due to cat damage in cars. This inturn changed the barrier protection levels and people thing that just because it say's synth on the bottle that it protects better.. WRONG!, A synth oil will provide lubrication longer due to it resisting oxidation of the base oil over a standard mineral oil.
Why do you think Amsoil's oil can run in a bike with out a problem but mobil 1's synth is not used and has been reported to be one of the problem oils for bikes? Because amsoil isn't api certified since they maintain higher levels of barrier additives and mobil has stayed with in the reg's for api certification or sj and sl which demands lower antiwear additives. The difference? both are synth's, but one has higher levels of barrier additives.
This is also true with mineral oils. Get the newer api certified oils, and it will give you the same problems.
Now let me also note here that some of the newer bikes maybe able to use standard motor oils due to the fact that one, it's water cooled, two, they don't share the tran's oil and motor oil together, three, they don't use roller pin bearings such as harley does, so many guys get a way with running conventional due to those reasons. Does that mean you can ? well, if the manufacture specs the oil, you should make sure it does qualify the same or better. In my case, I looked at the gear oil for my evo, sent it in for lab analysis, found it to be a 30wt with certain levels of additives, I then found what oils that schaeffers had that would meet that and more, and been running it since, no problem.
Same with m/c oils, go with what is spec'd or make sure your choice is better either by doing your homework and comparing analysis,(sorry, tech data sheets do not work when comparing these oils as they don't provide you with additive levels used) or you can get with some one like Dyson analysis, and he can help compare oils to ensure you are spec'ing out the right thing. Again, what you'll find, it makes no difference if it's synth or not as for the flat spotting on bearings.
Synth's really shine when you look at all the heat stress a bike can put on a oil, but you must worry first about the wear protection provided by the barrier additives in the oil first to avoid this bearing problem that they all falsly claim to be the synth oil sliding.
I'm not so sure this is totally accurate. From my research it seems that synthetic base oils (which are usually a blend of PAO and esters) will provide a better hydrodynamic film layer, which is harder to "break" than ANY conventional base oil. Thus, the EP/AW additives won't come into play as often with a synthetic as with a conventional motor oil.
To look at it another way, if you took straight PAO and Group I or Group II (with no additives), the PAO would be superior in maintaining hydrodynamic lubrication.
I totally disagree. Question,
Which flows easier, a synth or mineral base oil?
Which flows easier, a synth or mineral base oil?
just didn't see any reason to clutter the post so removed duplicate posting from above.
[ February 25, 2003, 05:20 PM: Message edited by: BOBISTHEOILGUY ]
I have thought about this issue and the bottom lien for me is: If there is so little friction that the rollers do not rotate, so what, there will not be any wear anyway.
In the last couple years or so have ya'll seen the term added to Synthetic gear that is called" shockproof "? What does that mean ?
It means Synthetics can be sheared like there is no tommorrow if,,,,,,ponder on it
[ February 25, 2003, 08:34 PM: Message edited by: dragboat ]
It means Synthetics can be sheared like there is no tommorrow if,,,,,,ponder on it
[ February 25, 2003, 08:34 PM: Message edited by: dragboat ]
are barrier additives high in delvac 1?
Ok, so since synth supposedly flows easier, that means when two surfaces squeeze together, then they hydrodynamic fluid of the synth would not be maintained as well as the mineral as it would flow out between the two surfaces faster, thus abandoning the film between the two surfaces. This is not normally the case and really isn't realitive to the wear protection issue, but point is, how does a synth that flows easier keep a film of oil in the bearings longer compared to a mineral that supposedly flows slower..? It's not the hydrodynamic properties the base oil that is making the difference in the bikes oils for wear protection. You'll notice that mc oils have higher levels of barrier additives than conventional newer sj/sl oils. As you can also take note, what type of base oil would harley's new synth be that would be different than amsoil or m1 synth?, group what?, why could harley have a synth base oil that works which most likely isn't any better than those, and yet it can qualify to be used in thier bikes and not cause flat spotting of the bearings? It's not the base oil, it's the special additive package as they have mentioned several times.
Also, when talking about better film strength in synth's, that refers to a better atomic film strength which on the molecular level it is better as the chain of molecules cannot be sheared as easily unlike the molecular structure of a mineral base oil that can be sheared easier. As for hydrodyanic properties, the base stock molecular structure has an ionic tension which groups the molecules together thus creating a fluid, both mineral and synth are bonded by ionic tension of these molecules and both can be sheared by standard mechanical means. Fact is, even putting oil between your fingers, you can break this ionic(hydrodynamic) film but not the molecular(atomic level) film.
Another given point is that there is plenty of oil analysis listed that has proven out that mineral oils protect as well as given synth's but where the difference is when you start to extend beyond the base oils limitations, now we are seeing where the synth shine as the base oils molecules have not been oxidized as bad thus allowing extended drains.
One other thing I have noticed as time progresses, that an average synth oil actually has higher barrier additives than most conventional mineral oils, so if the base hydrodynamic film stregth of a synth oil is much better, why would you need higher levels of barrier additives? seems to reason it would allow for less. FWIW, go to the VOA section and look at the barrier additive levels of most synths' in comparision of mineral counterparts.
Well, we're not talking about a single shot of oil being squeezed out. We're talking about oil flow. And just because a particular oil has a lower coefficient of friction doesn't mean that the hydrodynamic film is more fragile than one with a higher coefficient. And least I can't see why it would.
Edit: Here's a quote from MolaKule in another thread: "Synthetics offer more slipperiness, higher film strengths, wider VII, better heat conduction, and higher shear strengths, and better thermal and oxidative stability."
[ February 25, 2003, 10:32 PM: Message edited by: G-Man II ]
Delvac 1 has good barrier additives but GeorgeCLS or Molakule know better than I. Probably Mobil's best oil.
Well, we're not talking about a single shot of oil being squeezed out. We're talking about oil flow. And just because a particular oil has a lower coefficient of friction doesn't mean that the hydrodynamic film is more fragile than one with a higher coefficient. And least I can't see why it would. As you pointed out, it flows easier, which means it's slipperier as to be slippery, means the film will move around easier due to less friction(although I don't agree with synth being that) but using your answers, if it moves easier, which means it flows better, then it would tend to move out of a shear zone easier... My point here is that the esters and mineral compounds in base oils do not protect metal surfaces unless it can maintain hydrodynamic film and there is no difference when it comes to shear zones. Take a bearing on a crank, the oil is pumped in, to create a hydrodynamic wedge, both oils will do the same thing, that is why both oils can do the same job, but if the oils flow is too quick, it can squeeze out faster thus shearing/scuffing or if the oil is too slow, then if a low oil pressure condition exists like when at idle, then when acceleration occurs, the slower flow oil will take longer to flow into the bearing to provide the higher pressure or wedge effect as well again causing scuffing/shearing. Take the timken machine... Yeah, I know many don't think it shows anything, but it is demonstrating the same basic condition as in a crank and bearing is in. It is providing a wedge of base oil to the two surfaces while it is rotating, but when pressure is put on the bearing against the race, such as a piston does against the crank, it shears the hydrodynamic film of ANY oil as the oil is squeezed out around the sides of the bearings just like in a rod bearing against a crank. there is nothing to resist the flow at that point and can do this under certain conditions. Obviously, you don't put as much pressure on a rod bearing as on this machine but again, it makes no difference what base oil is used, the hydrodynamic properties of all oils will shear as they do not provide any kind of barrier protection but uses a wedge of oil between the two surfaces which under many types of conditions this exists. Again, I dis agree with the synth hydrodynamic film strength being better under normal oil change intervals as it is referring to atomic molecular film strength not fluid since we are talking two separate things. It's basic mechanics, fluid flows and shears no matter what, all of which vary from different degrees of flow, so the tighter the bearings, the better the wedge effect on the oil and the higher the pressure is the better the hydrodynamic film holds, but if what you say about synth's flowing easier, then it can also break easier, again, that isn't the case.
You failed to address my points about the barrier additive levels being higher in synth oils as well over mineral counter parts.. what gives, if hydrodynamic properties of synth can protect better, why then is it needed? Can you also explain why harley has had such a problem with synth oils on their roller bearings if my theory is incorrect? can you explain why mineral oils in the same basic oil drain intervals give as good or maybe even better wear #'s as synth's? How is it that we survived as long without synth's if mineral oils couldn't protect as well? yes, mineral oils have to be changed more often than synth's but again this is due to the atomic structure of the molecules of the two and yes this is where the atomic film strength DOES make a difference. Do me a favor and take the time to come up with answer to that before trying to respond to my answers, it just might give you some food for thought as many just assume that it's the base oil doing all the work when in fact why do we have all these additives to assist the base oils? Think on it
Edit: Here's a quote from MolaKule in another thread: "Synthetics offer more slipperiness, higher film strengths,(he and I have come to a difference of opinion on this many times, but he also stated to me one time that just maybe I might have a point here, not conclusive but I honestly think that the two terms are being used as one when in fact there is two seperate ways to look at this.) wider VII, better heat conduction, and higher(molecular) shear strengths, and better thermal and oxidative stability." (totally agree)
[ February 26, 2003, 11:02 AM: Message edited by: BOBISTHEOILGUY ]
You failed to address my points about the barrier additive levels being higher in synth oils as well over mineral counter parts.. what gives, if hydrodynamic properties of synth can protect better, why then is it needed? Can you also explain why harley has had such a problem with synth oils on their roller bearings if my theory is incorrect? can you explain why mineral oils in the same basic oil drain intervals give as good or maybe even better wear #'s as synth's? How is it that we survived as long without synth's if mineral oils couldn't protect as well? yes, mineral oils have to be changed more often than synth's but again this is due to the atomic structure of the molecules of the two and yes this is where the atomic film strength DOES make a difference. Do me a favor and take the time to come up with answer to that before trying to respond to my answers, it just might give you some food for thought as many just assume that it's the base oil doing all the work when in fact why do we have all these additives to assist the base oils? Think on it
Edit: Here's a quote from MolaKule in another thread: "Synthetics offer more slipperiness, higher film strengths,(he and I have come to a difference of opinion on this many times, but he also stated to me one time that just maybe I might have a point here, not conclusive but I honestly think that the two terms are being used as one when in fact there is two seperate ways to look at this.) wider VII, better heat conduction, and higher(molecular) shear strengths, and better thermal and oxidative stability." (totally agree)
[ February 26, 2003, 11:02 AM: Message edited by: BOBISTHEOILGUY ]
Yes, Mobil does an excellent job with the delvac oil. As for bikes, not sure how it would do.
MolaKule
Staff member
Ball bearings and roller bearings rotate inside a race. In order to avoid wear of course, an oil film should be established between the bearing and race, preferably a hydrodynamic film. In other words, it's preferable to be rotating on a film of oil.
Neither mineral oils nor synthetics cause any skipping. If somehow the bearing cage is lifted off the race and becomes eccentric with the centerline of the race (by external forces), skipping could happen. If the viscosity of the oil or grease is large AND the rotation speed is high, a plowing effect will be observed in which the lubricant will build up in front of the bearing, and hydrodynamic (as in hydroplaning) forces could lift it slightly.
Boundary additives, such as FM's and AW/EP's, are those that work under mixed or boundary lubrication regimes.
Synthetic base oils have lower coefficients of friction than do mineral oils. Synthetic oils also have higher bulk film strengths (as proven by ASTM 3328), better thermal and oxidative stability, and better base VI's than do mineral oils.
Synthetic base oils have better friction modification (reduction) as compared to mineral oils. FM additives added to BOTH synthetic and mineral oils reduce the friction coefficient of the oil by another magnitude.
No currently available (to consumers) oils by themselves can provide Extreme Pressure reisistance without additives. This is where the AW/EP additives come into play. Some of these additives are ZDDP, MoTDC, SnTDC, Boron (Borate-type) Esters, concentrated Calcium Carbonate Sulfonates, Phosphate Esters, Sulferized olefins, Nitrogen compounds, and others.
In my area, we are currently working with esters in which the molecules burrow into the metal with the potential end result being a base oil that needs no FM or AW barrier additives. In other words, if you can provide a surface of slippery molecules that do not allow two metal surfaces to exchange base metal molecules, the coefficient of friction is 0.0001 or lower and wear is almost unmeasurable.
[ February 26, 2003, 01:17 PM: Message edited by: MolaKule ]
Neither mineral oils nor synthetics cause any skipping. If somehow the bearing cage is lifted off the race and becomes eccentric with the centerline of the race (by external forces), skipping could happen. If the viscosity of the oil or grease is large AND the rotation speed is high, a plowing effect will be observed in which the lubricant will build up in front of the bearing, and hydrodynamic (as in hydroplaning) forces could lift it slightly.
Boundary additives, such as FM's and AW/EP's, are those that work under mixed or boundary lubrication regimes.
Synthetic base oils have lower coefficients of friction than do mineral oils. Synthetic oils also have higher bulk film strengths (as proven by ASTM 3328), better thermal and oxidative stability, and better base VI's than do mineral oils.
Synthetic base oils have better friction modification (reduction) as compared to mineral oils. FM additives added to BOTH synthetic and mineral oils reduce the friction coefficient of the oil by another magnitude.
No currently available (to consumers) oils by themselves can provide Extreme Pressure reisistance without additives. This is where the AW/EP additives come into play. Some of these additives are ZDDP, MoTDC, SnTDC, Boron (Borate-type) Esters, concentrated Calcium Carbonate Sulfonates, Phosphate Esters, Sulferized olefins, Nitrogen compounds, and others.
In my area, we are currently working with esters in which the molecules burrow into the metal with the potential end result being a base oil that needs no FM or AW barrier additives. In other words, if you can provide a surface of slippery molecules that do not allow two metal surfaces to exchange base metal molecules, the coefficient of friction is 0.0001 or lower and wear is almost unmeasurable.
[ February 26, 2003, 01:17 PM: Message edited by: MolaKule ]
Molakule, Are you familiar with Militech lube at all? Sounds like it might be a similar acting substance.
This would make sense,Militec-1 is a registered trademark of Adaptive Molecular Technologys. I thought it was just advertisment hype. How do the ester's burrow, it must be beyond just the polarity of molecules
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