Why does shift feel deteriorate on shared sump/trans engines

[02SE]

Originally Posted by blupupher
Originally Posted by BusyLittleShop
Originally Posted by blupupher

so an adjustment could be a fix (except for hydraulic clutches, if you are bubble free with fresh fluid there is not adjustment that I know of).


Brembo radial clutch levers are adjustable...

Don't think they make those for an 1100 Shadow. Maybe there are other ones out there that do fit though.


You could install one on your Shadow if you wanted to.

 

[Cujet]

For those willing to experiment in a bike they don't care much about, try a straight 30w oil with no additives and see if the same thing happens at the same miles. Might have nothing to do with additives and everything to do with oil contamination.

I'm a very experienced motorcyclist and have noticed this phenomenon on some bikes. I'm not at all sure it's clutch related as many of bikes exhibit no clutch issues or dragging and no change in clutch action after an oil change. But shifting improves immediately.

I'm guessing oil contamination. Evaporated residue from unburned fuel and carbon. Shared sump might be the clue.

 

[bonjo]

Busy's check looks interesting and I will check it out.
I find that with the bike on rear stand the rear wheel creeps round slowly with no gears engaged! I was told it is normal

just can't remember if the engine was cold or not.
Slipper clutch can affect the test maybe.

Engine oil in bikes have a tough life. Shearing and foaming would affect the gear change.
I have accepted the fact that gear change deteriorates as the oil ages with use

 

[ZeeOSix]

Originally Posted by bonjo
I find that with the bike on rear stand the rear wheel creeps round slowly with no gears engaged! I was told it is normal

just can't remember if the engine was cold or not.
Slipper clutch can affect the test maybe.


I mentioned in an earlier post why the rear wheel can still rotate with the clutch fully disengaged - it's oil friction between all the clutch plates. The oil friction/drag will be worse with cold thick oil.

If the clutch really is not fully disengaged with the clutch lever fully pulled, then trying to stop the spinning rear wheel with a little hand friction on the tire (use a leather glove) will not be easy to do.

 

[BusyLittleShop]

Originally Posted by blupupher

Don't think they make those for an 1100 Shadow. Maybe there are other ones out there that do fit though.


You're right... it wasn't made to fit your 1100 cable actuated clutch...

 

[02SE]

Originally Posted by BusyLittleShop
Originally Posted by blupupher

Don't think they make those for an 1100 Shadow. Maybe there are other ones out there that do fit though.


You're right... it wasn't made to fit your 1100 cable actuated clutch...


Unless he has a hydraulic clutch like some '94 Shadow's did...

 

[blupupher]

Originally Posted by 02SE
Originally Posted by BusyLittleShop
Originally Posted by blupupher

Don't think they make those for an 1100 Shadow. Maybe there are other ones out there that do fit though.


You're right... it wasn't made to fit your 1100 cable actuated clutch...


Unless he has a hydraulic clutch like some '94 Shadow's did...

All '87-94 1100 Shadows have hydraulic clutches (and some '95-'96).

Regardless, not something I would spend however much they cost vs changing oil a little early.

 

[02SE]

I thought that was the case. But never having owned a Shadow, thought there might be some variation among the various versions over the years.

 

[kmrcstintn]

new oil...full additive levels, minimal contamination from old oil still in galleries, viscosity improvers in great shape, no thermal damage, no shearing

older oil...lower additive levels, contamination from multiple operating cycles, viscosity improvers becoming damaged/used up, thermal damage from repetitive operating cycles, shearing happens which thins the oil & reduces the cushion between moving parts

change oil...shifting feels better

 

[bubbatime]

Have you tried a conventional motorcycle oil? I had terrible shifting with the synthetic oils I tried. Went to Valvoline conventional motorcycle 10W40, shifts perfect.

Give it a try.

 

[ZeeOSix]

Originally Posted by bubbatime
Have you tried a conventional motorcycle oil? I had terrible shifting with the synthetic oils I tried. Went to Valvoline conventional motorcycle 10W40, shifts perfect.

Give it a try.


I've been using Valvoline 10W-40 4-stroke cycle oil in my bikes and they shift pretty good. I only run the oil 3~4K miles so shifting doesn't seem to change over that use period.

 

[Panos]

Originally Posted by JmanG
My question is, why does shift feel deteriorate so soon on a shared sump motorcycle where the engine and transmision share the ssame oil? Ill get a little specific with my example. I've got a Honda 2007 CBR600RR, and ive just passed 48,000 miles on this motorcycle, runs great, no consumption that im aware of. No matter what brand 10w40 JASO2 spec oil i use, gear shifter feel greatly deteriorates after 1500 miles and begins feeling super notchy, with the first gear through neutral upshift into second being the most harsh with 2-6 still a little notchy but not as bad. For that reason, ive made a habit of changing the oil every 2000 miles. And with fresh oil, the gear changes are as smooth as butter again. Now ive used all the name brands in 10w40 weight, Amsoil Metric, Castrol Power 1, Motul 300v, Rotella T6 etc. And no matter what brand, at around that 1500 mile mark, the shifty gets notchy. Now ive read many UOA's on the oils im using and it seems they stay in grade well past 2000 miles. So whats happening with the oil that's causing this notchy feeling?

I should add I use this bike to commute to work yearly, 20-25 minute ride each way to and from work with the coolant temps reading between 165F(thermostat) and 205F when the rad fan kicks on so i certainly feel the oil is getting properly heated up to burn off the moisture.


My 2013 CBR600F PC41 uses the same (detuned) engine.I use a 10w30 fully synthetic oil,as the user manual defines only 10W30 as the correct viscocity.After 25.000kms and 6.000km OCI's ,never noticed even the slightest change in shifting quality.
So I suggest you should use a 10W30 oil and see what happens.

 

[DGXR]

Short answer is that the transmission gears will shear (or "chew the [censored] out of") the common oil, causing it to thin out with use so that the shifting mechanisms feel more notchy with thinner oil. This effect is exaggerated by the fact that the oil has to meet the requirements of two different systems at the same time. So instead of doing one thing very well, it does two things "OK." When the sumps are separated, as in a car or some other motorcycles, the oils are highly specialized for each system and lasts a lot longer in service.

This increased shearing effect is also common in some engines where oil squirters or other high-pressure oil systems are used... some engines are just very hard on oil.

 

[Needleman]

It could be vi improver permanent shearing, since no friction modifiers are used.

 

[JPowell490]

I will call BS that you have ran 10w40 Motul 300v motorcycle oil. Your usual oil is Rotella because it is cheap and you want me to believe you splurged for Motul?

Come on now, if you did, we wouldn't be having this conversation. Your shifting would be butter.

You also have 48k miles on a transmission. Could have been rode hard, etc. Could even need a new clutch.