View Point:
Technical information for the non-factory rider
By Tom Fleming

Special thanks to Danny Massie of the Maxima Oil Company.
Everyone knows or at least has heard of Professor Gary Bailey.
Mr. Bailey teaches in his MX schools that your clutch is the "foundation" for providing horsepower to the rear wheel. If this is true then why are we neglecting our clutch & gearboxes?
Wait a minute your thinking, this does not apply to me! "I change the gear box oil after every time I ride!" Well, that may be true… but, why are you using automobile motor oil in your 2-stroke clutch & gearbox, and for those of you riding 4-strokes don't think for a minute you are off the hook, you are just as bad off as the 2-stroke pilots!

We looked at two YZ-250's just to make an example. Motorcycle A was used for MX (Expert level rider) and the other, YZ-250 motorcycle B are used for hare scrambles (At A rider level). We used 20-50 Motor oil in motorcycle A and in motorcycle B we used # 85 two stroke gear box lubricatcant. What we discovered was we had a lot of questions and no answers. We did experience clutch & internal gearbox failures using the 20-50 motor oil and frankly to our surprise we did not experience any failures with the hare Scrambles motorcycle.
The test information was taken from an 11-month period. To make this more of a real and practical test the two riders did not know they were collecting data.

These results could have gone either way, but, as it turned out after converting the MX bike A over to the #85 gear box lubricant we saw a decline in failures, and an increase in performance! What did we do? Surely it is not just this simple? This made me think to ask riders this question, "just what do you use for gearbox lubricant and how often do you change it?"

I can safely say over 90% of the riders I spoke to, use automotive motor oil in their gearboxes and feel they are doing the right thing.

I was able to reach Danny Massie from Maxima oil. The following is an article written by Danny regarding his product. What he has to say is important. I hope you find his information as valuable as I have.

Wouldn't it be great to have one lubricant that could do it all? With just one bottle, you could magically lubricate your engine, protect the clutch and gears and with whatever was left, oil the air filter. For some, this may sound normal. Why not use this magical fluid? I hope by reading this I can help clarify why this magical fluid cannot 'Do All' as some may think. Sure, you can use it, but what are you really saving? Certainly not your clutch or motor. Maybe your saving a few bucks--That all depends on your time frame. Does the price of a new clutch get any cheaper in 6 months or a year?

The magical fluid I am referring to is automotive 4-cycle engine oil. These oils are developed with a specific goal in mind, to lubricate and protect a car's engine. Most of us would agree that our motorcycles operate in different environments than do our cars and likewise our engines have different appetites. Many off-road bikes are air-cooled and have increased power output ratios, which generate increased heat and strain on the engine.

The motorcycle and automotive industries have taken alternate routes when it comes to developing oil. The automotive industry is pushing higher gas mileage and lower emissions. While this sounds good to all of us motorcyclists, we need to look at how they are achieving this and how this relates to using this fluid in our 2-cycle transmissions and 4-cycle engines containing wet clutches.

Automotive oils, such as Castrol 20w50, use the latest in automotive additives classified as SJ. To qualify as an SJ rated oil, there are maximum levels of zinc and phosphorous that can be contained in the formula and specific performance levels that must be achieved using an SJ rated additive (i.e., mpg.) The levels of zinc and phosphorous in SJ oils is much less than those levels found in motorcycle specific oils. The government has also mandated to automotive OEM's that gas mileage must be increased in late model cars to help deter the negative effects of exhaust emissions. The OEM's can accomplish this task by adding friction modifiers to their oils, hence reducing friction and improving gas mileage.

Sounds good, but remember for every action there is a reaction. What did the zinc and phosphorous do anyway? Zinc and phosphorous are excellent antiwear and extreme-pressure (EP) additives that act as a safety net in your engine and gearbox. By forming a protective film, they prevent metal-to-metal contact from occurring, which can save you from a costly seizure. Thus, removing or minimizing the amount of EP additives in your crankcase and gearbox can ultimately wind up compromising the protection offered by the oil.

Secondly, the additional friction modifiers added to increase fuel economy react on your clutch plate surfaces, causing them to slip and in turn, generate increased heat and premature wear and deformation of the clutch plates. Once the clutch begins to slip, a downward spiral begins and the run-away heat can prove to be detrimental to your ride, race and equipment. A DNF is never fun.

So what's going on in your gearbox and what technologies are available to optimize the coefficient of friction on the clutch plates while providing superior protection for your gears? There is no question that the gearbox environment is dynamic. To answer this let's take a look at what is going on in our gearboxes from an oil's standpoint. Localized heating--up to 500F, gears continuously meshing together, squeezing out the oil and shearing it down. The temperature rises and falls as the clutch engages and disengages. As you pull away, out of the turn, you fan the clutch to get back on the pipe…series race #1, just 75 more minutes.

Transmission oil's primary goal is to lubricate and protect. The oil must not only protect critical drive components, but must protect itself in order to remain as a functional lubricant. The first thing we will look at is what happens to oil when it's continuously ran through the gearbox. The gears act as knives, cutting the oil molecules, trying to break their cohesive bonds. This action is referred to as shearing. There is a plethora of base oils to choose from, each of them having different characteristics, some oils more shear stable than others. Choosing a high quality base stock is one of the first steps to consider when formulating a 2-cycle transmission lubricant.

What happens to the gears when the oil is squeezed out of the gear's teeth? Remember the antiwear/EP safety net mentioned earlier? Gear tolerances are generally very tight, when the oil is squeezed out, the protective EP layer chemically reacts with the metal surface to form a film with a lower shear strength than the metal, thereby preventing metal-to-metal contact.

Whenever you heat and cool surfaces you get condensation. This condensation when mixed with oil forms destructive acids. These corrosive acids begin etching metal surfaces and cause the formation of deposits & sludge, as well as, degrading the quality of the oil. The lubricant must be oxidatively stable to work in the wide temperature range found in the clutch/transmission arena. Additives are blended into the oil to neutralize these acids and to protect against the formation of deposits. Detergents are used to clean internal components. Detergents chemically react with sludge and varnish precursors to neutralize them and keep them soluble. Contaminants are then bonded by polar attraction to dispersants, preventing agglomeration and keeping them in suspension.

Viscosity also plays a role in how your clutch will work. It's important to note that engine and gear oils have a different weight rating system; 85wt. gear oil is equivalent to 30wt. engine oil. How this relates to your gearbox is two-fold. First, the thicker the oil, the thicker the film of oil will be on the metal surfaces, providing you with a little extra cushion. The second side to this is the more viscous the fluid, the longer it takes to squeeze out of the clutch plates hindering the clutches ability to hook-up. We have found that 75-85wt. oils work ideally.

The last thing I would like to mention is the frictional properties of the base fluid used and of the additive system chosen. One friction test performed is the VC-70. The VC-70 is a very expensive and complex testing procedure that produces tons of data and many graphs. Within the procedure, 13 different frictional materials are tested with a wet clutch system engaging hundreds of times. This data is then compiled and analyzed by engineers to determine which properties are most beneficial. Does this test sound like anything an automotive oil formulator would be willing to spend money for?

So you see, the oil must lubricate, cool, provide protection against rust & corrosion, be thermally and oxidatively stable, provide detergency, dispersancy and boundary lubrication all the while protecting the clutch and minimizing clutch slippage. Possible? Absolutely.

The oil you put in your transmission must be able to endure the abuse that you put it through. The unique environment of the clutch and transmission must be taken into consideration when choosing an oil. This is why it is important to choose an oil blended specifically for motorcycle transmissions with wet clutches.

Motorcycle transmission oils, like those produced by Maxima, have been blended to exceed OEM specifications and to survive the tortures incurred in your motorcycle's gearbox. Some riders are easier on clutches than others and may be able to get by using automotive grade oils on their bike's wet clutch. Others may not be so fortunate. The additional friction modifiers found in automotive engine oils will plate out on the surfaces of the clutch causing slippage. Those of us that use the clutch much increase our chances of glazing the clutch with every pull of the lever.

This fact becomes even more important when considering an engine oil for your 4-stroke bike that has a wet clutch. You must also now protect your engine with the same lubricant. Not only will the number of miles put on the oil likely increase, but it is also being exposed to the harsh environment of the combustion chamber. Keep in mind here that you want to look for an oil labeled Motorcycle Specific (JASO MA--for wet clutches) and one that is using an SG additive system (containing higher levels of zinc and phosphorous.)

It's important to note that there are numerous base fluids to choose from when building a formula and equally as many additives to blend in. Each component within the formula has a role to play whether it's lubrication, detergency or controlling the formation of harmful acids. The single most important concept I can offer you when building a high performance oil is Balance. Balance is the strength behind the formula. Too much of a good thing isn't always better. Imagine for a moment that you are a baker making chocolate chip cookies. You continue adding those delicious morsels--more and more chocolate chips. Soon, you won't have chocolate chip cookies anymore; you have changed the chemistry. What you now have is chocolate chunk delight with a breadcrumb topping.

Review Part 1
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