Oil's affect on motorcycle gear shift feel?

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Besides viscosity, what is it about oil that creates smooth shifting and dampens notchiness? In fact, two different and high quality oils with the same viscosity can feel very different. Any input would be appreciated. Thanks.
 
My 1998 Honda CBR900RR spec'd 10w40, and at one point I tried 20w50 full synthetic to see if that might do exactly as you describe. It didn't, and in fact made it shift noticeably worse. I ended up going to the same Chevron Delo 400 15w40 that I use in my diesel truck, and it worked beautifully with that.
 
In my case it's a 2014 Kawasaki zx14r. 15w40 felt fine (shell) and 15w50 (m1) shifts fine. 10w40 m1 high mileage however is pretty darn notchy. I just changed it and may dump it for other use.
 
Originally Posted By: digitalSniperX1
In my case it's a 2014 Kawasaki zx14r. 15w40 felt fine (shell) and 15w50 (m1) shifts fine. 10w40 m1 high mileage however is pretty darn notchy. I just changed it and may dump it for other use.

I have found that 15/40 HDEO oil works best in my bikes(DRZ 400, Suzuki 1500 and a 1100 Honda). I might even try it out in my Goldwing when I change the oil in it.

ROD
 
I think this question is pretty complicated. We try oils find some we like and some we don't ( for the shift feel ). What we don't know is what the oil blender has done or not done to produce the best results. I think we probably all agree that notchy, clunky shifts are not desired and smooth, cushy shifts are what we desire.
 
Originally Posted By: digitalSniperX1
In my case it's a 2014 Kawasaki zx14r. 15w40 felt fine (shell) and 15w50 (m1) shifts fine. 10w40 m1 high mileage however is pretty darn notchy. I just changed it and may dump it for other use.


Why the Mobil 1 HM oil in the ZX14r ?

My KZ 1000 shifts the same no matter what oil is used. Haven't had my Concours 14 long enough but it's been the same shift wise on M1 4T 10W-40, M1 V-Twin, M1 15W-50, Rotella 15W-40.

Like you, I would also like to know what would make shifting change between brands/types of oil.
 
My Ducati didn't seem to care much either but it mostly got amsoil. Tried m1 hm in it seemed fine. And 15w40.
 
Interesting this thread is when it is, as I just changed oil 500 miles ago in the Ducati and switched brands from Silkolene to Spectro. Pretty radical shift from a full ester oil to a PAO/ester blend that's more PAO than ester in the blend ratio. The Spectro's chemistry must still be in the process of setting up because it feels notchy in the gear box. Both the Silko and the Spectro were 15W50.

Best oil for the gears was Mobil 1 Racing 4T 10W40. The bike just shifted like butter and the clutch was smooth yet positive. But in the summer the Mobil 4T 40 weight was too thin and the desmo valve train noise was louder than I was comfortable with.

I'm sure the Spectro's chemistry will set up on the metal surfaces in a few hundred more miles, but for now it feels worse than the silkolene in the gears and clutch action.
 
Some bikes are different. The 87 klr I bought 2 years ago is like that. Its notchy on delo, but the first highway run of the day it slips on the on ramp for 30 sec or so
Rotella is too slick feeling and its hard to find gears, but didn't slip as bad.

Probably the warn clutch has something to do with it....
 
I've only had my V45 Sabre for 33 years, but only one oil ever caused poor shifting. I drained the Valvo synth 4T 10W40 after 500 miles. Thought my hydraulic clutch system was the culprit and then changed the oil on a whim. The Castrol Act Evo 10W40 immediately shifted like butter. The Valvo synth is going in the mower.
 
One thing I feel is that, with milege piling up, the shifting smoothness decai, same with Viscosity Index Improvers in the oil ... or the ZDDP depletion. I belive that's a close relation between the shearing of VII and the smoothing loss. Best oil for me was the Mobil 1 15w50 EP API SL (a car oil!), with (more) ZDDP additive added by myself. The silk shifting went for longer time.
 
My FZ6R is a Notchy bike as most Yamaha's are. Ive ran M1 10w40 4T and Amsoil 10w40 Metric in the bike.

1-2 is cluncky on both oils, but it does shift smoother going up from 2nd with the Amsoil.

After the 1st 100miles it seemed the same. the next time i rode it was noticeably smoother with the Amsoil.
 
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Shift feel is down to viscosity and friction modification.

If you want a nice smooth shift feel and have a wet clutch with specific FM requirements, look at Redline and/or Motul.
 
Originally Posted By: AlaskaMike
My 1998 Honda CBR900RR spec'd 10w40, and at one point I tried 20w50 full synthetic to see if that might do exactly as you describe. It didn't, and in fact made it shift noticeably worse. I ended up going to the same Chevron Delo 400 15w40 that I use in my diesel truck, and it worked beautifully with that.


Always liked conventional 15/40 HEDOs in my metrics as well as conventional 20/50s.
 
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