A NOTE ON THE POTENTIAL FOR HAND FATIGUE WITH STIFFER CLUTCH SPRINGS:
Depending on just how stiff, the stiffer clutch springs might be, that people upgrade to, it may be possible to experience hand fatigue, if the bike is ridden in traffic with a lot of stop lights. However, even many stop lights in your ride, do not have to cause hand fatigue in most cases, if you are smart about the way you operate the clutch. I have observed countless times, that motorcycle riders, especially younger riders who are not technically savvy, will sit at a 2 minute stop light, HOLDING THE CLUTCH IN, the entire time. WOW!!! That is just asking for hand fatigue. You should NEVER do that in the first place. So, if you stop that ill-advised behavior, it could eliminate hand fatigue that those riders may experience.
The reasons you should NEVER do that include:
• It causes hand fatigue
• It puts totally unnecessary and excessive side-loading on the clutch disengagement bearing, and other bearings on that shaft
• It adds heat to the oil as the clutch plates slide over each other
• And though not a technical issue, it makes you look like a total beginner who doesn’t even know what you are doing, which in this case would be true
Consider this: If you click the transmission into neutral as you come up to a stoplight, it takes only 1 second’s worth of a clutch lever pull. That compares to 120 seconds worth of a clutch pull if you sit there and hold the clutch in for a full 2 minute stop light. If you encounter say 10 stop lights on the way to your destination, and 10 stop lights on the way back, for a total of 20 stop lights in a single day. That equals 2,400 seconds of holding the clutch in per day, vs 20 seconds if you simply put the transmission in neutral each time and let the clutch back out while you sit there.
In a 5 day work week, that equals 12,000 seconds, or 200 minutes, or 3.3 hours PER WORK WEEK that you sat there holding the clutch in. PER MONTH, that equals more than 13 HOURS of holding the clutch in!!! You can see how crazy that is. So, you do NOT have to be a Medical Doctor or have a PhD in Mechanical Engineering, to see that holding the clutch in when it is not needed, is a TERRIBLE IDEA. So, if you are guilty of doing that, do your hand and your bearings a favor, and STOP DOING IT. And of course it only takes another 1 second’s worth of a clutch pull, to stab the transmission back into gear, to get rolling again.
The same thing applies to holding the clutch pedal down on cars and trucks at a stop light. You are putting unnecessary wear and tear on the clutch’s throw out bearing and on the crankshaft’s thrust bearing. If you are guilty of doing that, you should do yourself a favor, and STOP doing that as well.
On a related note, you can also further improve the clutch action of a motorcycle by carefully bending the clutch lever end further outward away from the handlebar, so the clutch lever to handlebar contact point, is about 10 mm or 3/8″ further away from the handlebar, when the lever is released to its resting position. This provides a little extra clutch disengagement, which makes it easier to find neutral, and allows for easier shifting. I also did this with the motorcycles I used to have.
The way to do that without damaging or breaking the clutch lever, is to wrap the lever in a couple of layers of rags. Then use a large box end wrench for leverage to carefully, controllably, slowly, and repeatedly bend the lever forward a little at a time. For that bending operation, position the box end of the wrench over/around the lever, at several places along the lever, for a little bending at each location, between about a third of the way out from the pivot, to about two thirds of the way out from the pivot. You don’t want to try and bend it too close to the pivot, or too close the tip. I have done that many times with no problem.
Even if people don’t want to deal with changing or shimming clutch springs, they can still run a quality high performance 5W30 Resource Conserving Automotive motor oil that provides FAR BETTER engine and transmission wear protection than all but one Motorcycle oil I have tested. And high performance automotive oils will also typically provide more HP and better MPG, compared to low performing motorcycle oils.
When motorcycle clutch discs do eventually become old, worn, glazed, hardened, and have lost their normal gripping capability, they can be more prone to slippage with 5W30 Resource Conserving Automotive motor oils than with poor performing motorcycle oils. But, by then the clutch discs are due for replacement anyway. And it is far better to replace the clutch then, rather than compromise their bike’s engine and transmission wear protection for years, from using poor performing motorcycle oils.
Under anything near normal bike riding conditions, any eventual old worn clutch slippage issue will be a gradual thing over time. It will not just suddenly slip completely and leave you stranded. And if push comes to shove, you can always change back to poor performing motorcycle oil, to stretch out the use of an old worn clutch, for a little longer.
Just below is a comparison between the top High Performance Automotive 5W30 oils and the motorcycle oils I have tested (the higher the psi, the better the wear protection). Keep in mind, that my Engineering Motor Oil Torture Test determines every oil’s “film strength/load carrying capability/shear resistance value”, which all mean the same thing and exactly apply to motorcycle conditions with the transmission gears sharing the same oil with the engine, and are represented by the psi value posted in my Wear Protection Ranking List.
Therefore, my testing DOES take into account a motor oil’s capability to withstand with the higher levels of mechanical shearing found in most motorcycle engines. Oils marketed as “Motorcycle Oils” sometimes make claims about their better ability to deal with the higher levels of mechanical shearing found in most motorcycle engines. But, my Engineering Testing shows that those motorcycle oils are only making false advertising claims that do NOT stand up when actually put to the test.
* 5W30 Amsoil Signature Series synthetic “automotive oil” = 134,352 psi, ranked 3rd out of 229 motor oils tested so far.
* 5W30 Quaker State Ultimate Durability synthetic “automotive oil” = 133,125 psi, ranked 4th out of 229 motor oils tested so far.
* 5W30 Motul 300V motorcycle oil = 112,464 psi, ranked 25th
* 10W40 Mobil 1 Racing 4T motorcycle oil = 93,661 psi, ranked 90th
* 20W50 Mobil 1 V-Twin motorcycle oil = 75,855 psi, ranked 163rd
* 10W30 ProHonda HP4S motorcycle oil = 66,852 psi, ranked 205th
* 10W40 Valvoline 4 Stroke motorcycle oil = 65,553 psi, ranked 210th
* 10W40 Spectro Motor-Guard High Performance Motorcycle Oil = 57,977 psi, ranked 224th
As you can see, the best High Performance Automotive oils provide FAR BETTER engine and transmission wear protection than most “motorcycle oils”. And as mentioned above, automotive motor oils also typically provide more HP and better MPG, compared to the lower performing motorcycle oils.
Most motorcycle engines:
* Make far more power per cubic inch, than car engines.
* Rev far higher than car engines.
* Typically get run much harder than most car engines.
*Share the same oil for both the engine and the transmission, which subjects the oil to considerably higher levels of mechanical shearing.
Therefore, I recommend using High Performance Automotive oils in motorcycles, wet clutch or not.
So, at the end of the day, motorcycle owners have to ask themselves if they really want to run a poor performing motorcycle oil in their beloved bike, or if they would be better off using a FAR SUPERIOR High Performance Automotive motor oil? The choice is theirs.