Loss of shift smoothness (oil related, not mechanical).

Try the M1 10W-40 motorcycle oil. I've had great results with it.

M1 10w40 4T or 20w50 VTwin are bomb proof with respect to maintaining shift quality on 5000+ mile OCI's in my ZRX 1200. With the mods done, it puts down considerably more hp, but more specifically, more torque that grinds oil to its knees. M1 doesn't flinch in either variety. But how would I know as I haven't gotten my foot calibrated yet... I get a good chuckle that the ol' cut and paste has turned into the cut and run, don't see much of it when logic comes into the discussion.
 
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My experience with oil fading in shift quality has been similar to the OP's, including on street bikes. Have tried Rotella 15W40 - 1500 to 2k miles, Mobil 1 15W50 - 1800 - 2200 miles, and Mobil 1 4T 10W40 2000 - 2500 miles before I did not like the shift quality. I finally spent the extra to try Motul 300V 10W-40 moto specific, and there was no comparison to others. The difference was so pronounced it was like night and day. Went as high 5500 miles and shift quality (and engine/transmission quietness) was still fine, just chickened out from doing more because I was afraid wear metal contaminants might be getting close to condemnation levels.

I'm not saying only Motul 300V will solve the extra short OCI problem, but my thought was the major difference was in base oils: the others were Group 2/3 & 4 with a very slight amount of 5, the 300V was mostly 5 with the balance being 4. But I'll bet other Group 5 ester base oils would likely give a similarly fine longer OCI/ smooth shifting performance. Think about Redline, Maxima Ultra/Extra, Bel Ray (EX?), or Fuchs/ Silkolene Pro ester-based formulations.

Other upsides include the crankcase won't stink up your garage like hydro carbon based oils during tear downs, the oil will do a nice job of cleaning the engine internals, it has a tacky/ sticky quality to it that coats engine internals and does not drain off - so great protection is already in place every time the engine starts up, and many notice the oil runs cooler - I think this comes from ester's better heat transfer coefficient at surfaces and typically slightly higher density.

The downsides are: the price is about 2x what top quality Group 4 PAO-based oils sell for, they are virtually unavailable at stores aimed at commoners, and in the long term they "overcondition" seals and gaskets, causing them to slowly ooze small amounts oil which attracts dirt and dust.
 
CentAm, what bike did you run the M1 10w40 4T in? Not that my bike is more of an oil shearing device than others, other than it is a shared sump in-line 4 that makes a lot of torque all over and revs very high as well. It's a bummer M1 MC specific oil lasts for that short of a period in your bike relative to what I and a lot of others have experienced.
 
Bonz said:
> CentAm, what bike did you run the M1 10w40 4T in?

The one from my BITOG moniker - 2012 DL650, Suzuki Wee Strom. A 644cc V-twin with only 67 hp and 41 lb·ft torque, it's not at the ZX14 or Hyabusa level for meting out driveline punishment, so it should get even more mileage before shift quality drops off, all other thing being equal.

Admittedly, I'd like to think your simple explanation of shearing the oil's viscosity index improver in the clutches and gearset provides the explanation, but if it did, wouldn't you expect there to be an obvious marked difference in between the 100°C dynamic viscosity in the VOA and UOA? I think it came out well within spec for all of the non-300V MC oils.

I surmised the cause had something to do with the oil's friction coefficient changing during the oil change interval - like as result of combustion blowby, fuel contamination, or clutch pack material suspended in the oil. As I said in my previous post, a fresh oil change always perfectly resolved the problem, until it got enough mileage to gradually start coming back. But a change of 300V stayed great for the whole time it was in the crankcase, including well beyond the manufacturer's recommended 3500 mile OCI. So I stuck with it.

My current bike (2020 GSX-S1000F) is still breaking in at ~ 5k miles, so I'm still using a mineral MC oil to get to maybe 8 - 10k before switching over. This one seems to begin losing shift quality at ~1800 - 2000 miles on the Motul 3000 10W40 MC oil that's in it now.

Bonz said:
> It's a bummer M1 MC specific oil lasts for that short of a period in your bike relative to what I and a lot of others have experienced.

There's no need to think someone's favorite is the solution to every problem. If your were one of the chemists or blenders at Exxon-Mobil that came up with the formula for their 4T, I can see why you'd have something invested in it. If someone else came here and said they tried my suggestion of 300V (for street or off-road riding, read: not racing) and only got 2000 miles before the shift quality went south, I would 100% agree it was a waste of their $20+ per quart and they should try something else. The majority of us here are just riders and occasional mechanics, and the best we can do is learn from our experiences and honestly relate what we've learned.
 
The one from my BITOG moniker - 2012 DL650, Suzuki Wee Strom. A 644cc V-twin with only 67 hp and 41 lb·ft torque, it's not at the ZX14 or Hyabusa level for meting out driveline punishment, so it should get even more mileage before shift quality drops off, all other thing being equal.

Admittedly, I'd like to think your simple explanation of shearing the oil's viscosity index improver in the clutches and gearset provides the explanation, but if it did, wouldn't you expect there to be an obvious marked difference in between the 100°C dynamic viscosity in the VOA and UOA? I think it came out well within spec for all of the non-300V MC oils.

I surmised the cause had something to do with the oil's friction coefficient changing during the oil change interval - like as result of combustion blowby, fuel contamination, or clutch pack material suspended in the oil. As I said in my previous post, a fresh oil change always perfectly resolved the problem, until it got enough mileage to gradually start coming back. But a change of 300V stayed great for the whole time it was in the crankcase, including well beyond the manufacturer's recommended 3500 mile OCI. So I stuck with it.

My current bike (2020 GSX-S1000F) is still breaking in at ~ 5k miles, so I'm still using a mineral MC oil to get to maybe 8 - 10k before switching over. This one seems to begin losing shift quality at ~1800 - 2000 miles on the Motul 3000 10W40 MC oil that's in it now.



There's no need to think someone's favorite is the solution to every problem. If your were one of the chemists or blenders at Exxon-Mobil that came up with the formula for their 4T, I can see why you'd have something invested in it. If someone else came here and said they tried my suggestion of 300V (for street or off-road riding, read: not racing) and only got 2000 miles before the shift quality went south, I would 100% agree it was a waste of their $20+ per quart and they should try something else. The majority of us here are just riders and occasional mechanics, and the best we can do is learn from our experiences and honestly relate what we've learned.


Absolutely agree, it is each persons experience that helps to make the decisions on lots of things besides just motor oil, lol. I'm glad you have a long-term oil that keeps the shift quality where it should be. It's not any fun to have it fall off after spending a lot of money on the oil.
 
M1 10w40 4T or 20w50 VTwin are bomb proof with respect to maintaining shift quality on 5000+ mile OCI's in my ZRX 1200.
There is absolutly no API or SAE or JASO test that proves "shift quality"... after all the only proof of "shift quality' rest between the riders ears...
 
Sounds like maybe oil or additive breakdown ... causing more clutch heat.
I would use whatever "works" the best. Some car engine also do better with certain oil at least based on my experience.
 
There is absolutly no API or SAE or JASO test that proves "shift quality"... after all the only proof of "shift quality' rest between the riders ears...
You're a glutton for this, only one person in this thread and on this forum share your sentiments, and that is yourself. It's OK not to have something to say, and just leave a thread alone.
 
Look at post# 57, BLS. Do the blind corncob versus Charmin test. JASO doesn't have a spec for that but pretty clear the outcome.
 
Mercy Bonz... real scientist employ the Scientific Method which is the
real process of objectively establishing facts through testing and
experimentation. The basic process involves making an observation,
forming a hypothesis, making a prediction, conducting an experiment
and finally analyzing the results

SciMethod1.JPG




Scientific Method is not about making shift quality assumptions to a conclusion....

SciMethod2.jpg
 
Mercy Bonz... real scientist employ the Scientific Method which is the
real process of objectively establishing facts through testing and
experimentation. The basic process involves making an observation,
forming a hypothesis, making a prediction, conducting an experiment
and finally analyzing the results

View attachment 98794



Scientific Method is not about making shift quality assumptions to a conclusion....

View attachment 98795

Most people know the difference between picking up a 5lb weight vs a 10lb weight. Going through a rigorous scientific process to prove that one is heavier than the other is not needed.
 
You're a glutton for this, only one person in this thread and on this forum share your sentiments, and that is yourself. It's OK not to have something to say, and just leave a thread alone.
Like said before ... some people just are not fully connected to their machines. If someone can't tell a difference on what's going on with the bike's shift quality, then they are either not connected to the machine, and/or they have never used any other oils in their bike and change the oil so often that a change in shift quality can't be detected.
 
Like said before ... some people just are not fully connected to their machines. If someone can't tell a difference on what's going on with the bike's shift quality, then they are either not connected to the machine, and/or they have never used any other oils in their bike and change the oil so often that a change in shift quality can't be detected.
Shifting an constant mesh motorcycle gear box is a learned skill and
some riders with racing experience can up shift and down shift so
smoothly so seamless that the passenger along for the ride can not
feel or count them all with oil beyond the 8K OCI...

MrRC45TahoeSweeperCloseUp.JPG
 
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Most people know the difference between picking up a 5lb weight vs a 10lb weight. Going through a rigorous scientific process to prove that one is heavier than the other is not needed.
Granted only a Dumb Bell will guess wrong...
 
Granted only a Dumb Bell will guess wrong...

I never believed it before, but give some people enough rope and they will flat out hang themselves. Even if they won't try the corn cob versus Charmin test. I mean, like I said, you can't see what you're doing back there and there's no data so they must feel the same.
 
Shifting an constant mesh motorcycle gear box is a learned skill and
some riders with racing experience can up shift and down shift so
smoothly so seamless that the passenger along for the ride can not
feel or count them all with oil beyond the 8K OCI...


View attachment 98830
So now you're saying a passenger's "non-scientific" senses are valid and believable, and the guy riding the bike sense of shift quality isn't ? 😂
 
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Zee, am I just imagining it or when I was a kid at a farm auction back in the Midwest that a corn cob really did feel more rough than Charmin? Didn't have any data collector other than the outhouse pit, and I really couldn't contort myself enough to see what I was doing. According to BLS, I was fooled.

But apparently a passenger does have a better sense than the guy piloting the bike. Those Honda factory race bikes really must be supernatural, and who da' thunk a 30 weight oil would make it happen.
 
So now you're saying a passenger's "non-scientific" senses are valid and believable, and the guy riding the bike sense of shift quality isn't ? 😂
My RC45, true to its racing intent, is solo seat... I had to ride my customers on the back of their own bikes to demonstrate my point that smooth and seamless shifting was a learned skill... it was my way to encourage them to get their shifts together and stop blaming the bike or oil...
 

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