Oil's affect on motorcycle gear shift feel?

Status
Not open for further replies.
Originally Posted By: SlipperyPete
Why don't you guys start a freakin' bearing lubrication thread? I'm surprised a mod hasn't deleted all of your off topic [censored] and banned you both.


LoL ... yeah, let's ban people because a discussion got morphed into other side discussions about lubrication. This thread started going off track when oil squirters were starting to be discussed a year back, which isn't related to transmission shifting either. If everyone was banned for not staying 100% on topic there would probably be about 8 members left on this board.
 
Originally Posted By: Shannow
I started a thread on Honda's F1 engine here...

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4211293/1

And he took to that one too...defacto bearing thread now.


Oiling system design & operation, and journal bearing lubrication discussions are pretty on par in that thread because of the subject matter of the design aspects of the Honda F1 engine. It takes two (or more) to participate and run with a discussion.
 
It is agreed then that a motorcycle (and some cars & trucks) can be shifted without using the clutch.
Again, note that the typical motorcycle clutch does not engage the engine to the transmission, but the transmission to the final drive.
By causing slack in the transmission with the throttle, the shift is achieved with zero engine load or braking on the gears.
How then, if a lubricant is in the viscosity and additive ball park, could one make a significant difference to shift feel over another?
 
Last edited:
Originally Posted By: userfriendly

Again, note that the typical motorcycle clutch does not engage the engine to the transmission, but the transmission to the final drive.


The clutch is not on the output shaft, but on the input shaft, as in any transmission...but it is on the primary reduction, and so runs at less than engine speed, this is what helps with the shifts. Compare a normal unit construction motorcycle with a BMW and engine speed clutch and gearbox, although there is a small primary reduction. I can shift my BMW clutchless, but it's slower and takes more skill than the flick of the wrist as on a normal bike...downshifts are easier than upshifts on the BMW.
 
Can shifting characteristics be changed by playing with the primary drive ratios, adjusting the transmission input drive shaft rpm vs engine rpm?
 
On British bikes with chain primary drive, gearing changes were done with the engine sprocket. Done that many times back in the day, but never noticed any difference in shifting. Harder to do with gear primaries, but has been done. I have a Honda TLR200, the TLR250 has one less gear and a different primary ratio, it was done to get better gear ratios for trials riding...I've ridden the TLR250 and it's a completely different bike, mainly because of the gear ratios.
 
Originally Posted By: userfriendly
Again, note that the typical motorcycle clutch does not engage the engine to the transmission, but the transmission to the final drive.


The clutch certainly does connect and engage the engine's crankshaft to the transmissions input (main) shaft via the clutch. That's the whole purpose of a clutch in any vehicle.

On a motorcycle, the crankshaft is directly connected to the outer basket of the clutch by gears, and the inner basket of the clutch is directly connected to the transmission input shaft by splines. What connects and disconnects the engine's crankshaft (source of power) from the transmission are the clutch plates.
 
BLS
I may be wrong in respect to Mobil 1 5w30 API SN but my understanding is 5W30 car oils are designed to maximise fuel economy and to this end have friction modifiers in them that makes them incompatible with wet clutches.
The label in your picture shows it as 'Resource Conserving' which implies it is friction modified, conserving fuel.

Within reason, any oil grade recommended by the bike manufacturer is OK, so long as it is not a friction modified oil.
Ideally, a motorbike oil should have a Jaso MA rating, a classification based on the results of the JASO T 904:2006 clutch system friction test.
I have tried many non friction modified car oils that are not Jaso MA certified in wet clutch motorbikes and have never had any clutch slip issues.

And yes, i have noticed a difference in gear shift feel between some oils but more so, how long the shift feels good, before the oil sheers down.
IMO, to retain the 'shift feel' a newly installed oil provides for as long as possible, use a full synthetic, preferably a POA/Ester, and it so happens, the Motul you recommend is an Ester oil (fully synthesized and likely not from a petroleum base stock).

cheers
 
Originally Posted By: paulr1
And yes, i have noticed a difference in gear shift feel between some oils but more so, how long the shift feels good, before the oil sheers down.
IMO, to retain the 'shift feel' a newly installed oil provides for as long as possible, use a full synthetic


Or a monograde oil - environmental conditions permitting - which has no VII's to shear.
 
this response is based on the 'feel' of shifting of the various bikes I've had...

2008 Buell Blast...got H-D Syn 3 20w-50; didn't own too long & not alot of miles; N to 1st was always a clunk when cold...got a bit better when warm; rest of the gear changes seemed ok

2009 Yamaha V Star 650...liked 10w-40 synblend, conventional, or 10w-40/15w-40 frankenbrews; lost shifting feel (lots of false neutrals) with Mystik synblend 15w-50...dumped it after 200-300 miles

2 different 2009 Suzuki GZ250's...same likes as Yamaha V Star 650; tried some leftover SL rated 20w-50 (an off brand name owned by Castrol)...hard shifts & false neutrals; dumped the 20w-50 stuff after 300-400 miles

2006 Honda Shadow 750...loved any kind of 10w-40/15w-40 based frankenbrew; never tried any XXw-50

2014 Yamaha V Star 250...just turned over 1200 miles with multiple oil changes during the break-in period; money got tight so I used what I had on hand; blends of traveller hdeo 15w-40 & shell pcmo 10w-40 or traveller hdeo straight up; n to 1st gear are a bit clunky when cold yet shifting is good overall; still deciding what to use long term...
 
Last edited:
my 2012 bonneville shifts great, my 2013 victory is rough but getting better with miles + my 2016 bmw g650gs is between but has longer sloppy shifter! some bikes are just good shifters others not so much!!
 
Status
Not open for further replies.
Back
Top