Clutchless up shifts

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  #1  
Old 12-20-2008, 03:44 AM
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Default Clutchless up shifts

Hey ya'll, the other day i was reading about the old school 2-stroke Moto GP bikes and the article talked about how they used to up shift without their clutch because it was faster and it didn't upset the chassis like using the clutch did. So it got me thinking about us mere mortals and out bikes. What are ya'll thoughts? Surely it can't be healthy for us, who don't have a race crew to rebuild our tranny's after each race, to do it on occasion or at track days. So what do ya'll think?
 
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Old 12-21-2008, 12:04 AM
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I've done it a few times but i don't do it all of the time. I know with the slipper clutch it helps our bikes be a little faster and easier to handle. but shifitng with out it could hurt the trany if you don't do it at the right rpms.
 
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Old 12-21-2008, 08:49 AM
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Done it a few times myself but I'll go with Bluebeast... if you don't get it right then transmission wear.

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Old 12-22-2008, 01:28 PM
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yeah, that's what i was thinking too, just wanted some opinions
 
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Old 12-22-2008, 01:35 PM
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I pretty much only use the clutch for the 1st-2nd and 2nd-1st shift - don't use it for anything else unless i'm trying to be realy smooth on a casual jaunt around town.

its a lot easier on a bike than on a car due to the low mass of the parts allowing them to speed up and slow down quickly. I was used to doing it with cars to the point that if a clutch went out on a car (would not release) I was able to drive it normally except when starting and stoping.

so switching to a bike was easy - the upshift is easy - the downshift takes mroe finess

upshifting only requires you to back off the throttle enough that there is no tension on the gear teeth (or chain) and shift, then throttle up again.

downshifting you ease off the throttle a to release tension form the gear teeth, then just as you shift you blip the throttle then release, this helps match the engine rpms to the gear rpms mid shift.

done properly its seemless ans smooth and fast.

oh yes, and up untill the weather hit the sub freezing temps, I commute on my bike every day.
 

Last edited by Kohburn; 12-22-2008 at 02:17 PM.
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Old 12-22-2008, 02:06 PM
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+1 with Kohburn
19K mi no problems. its very easy to do.
 
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Old 12-23-2008, 01:12 AM
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Originally Posted by Kohburn
I pretty much only use the clutch for the 1st-2nd and 2nd-1st shift - don't use it for anything else unless i'm trying to be realy smooth on a casual jaunt around town.

its a lot easier on a bike than on a car due to the low mass of the parts allowing them to speed up and slow down quickly. I was used to doing it with cars to the point that if a clutch went out on a car (would not release) I was able to drive it normally except when starting and stoping.

so switching to a bike was easy - the upshift is easy - the downshift takes mroe finess

upshifting only requires you to back off the throttle enough that there is no tension on the gear teeth (or chain) and shift, then throttle up again.

downshifting you ease off the throttle a to release tension form the gear teeth, then just as you shift you blip the throttle then release, this helps match the engine rpms to the gear rpms mid shift.

done properly its seemless ans smooth and fast.

oh yes, and up untill the weather hit the sub freezing temps, I commute on my bike every day.
+1^! That's how it's done. A little practice and you'll be a pro. If you do it just right, your clutch will last longer. Also, try blipping the throttle when you downshift with the clutch. It will make your downshifts smoother and less jerky. This works best at the start before leaning into while entering turns. By doing that. you are letting the engine rpm catch up with the lower gearing rpm of the wheel/ transmission as you downshift. Saves you time & makes you faster especially on the track/ trackdays.
 

Last edited by speedracer138; 12-23-2008 at 01:15 AM.
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Old 12-23-2008, 03:47 AM
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the slipper is one-way. it doesn't really affect an upshift.

the trans is constant-mesh.. all 12 gears are spinning at one and they're designed to be clutchlessly upshifted with no fear of blowing into tiny bits.

you CAN blow them up, and theres a multitude of reasons as to why gears and dogs and forks have failed, but normally, a blip of the throttle or a ignition cutout switch in the linkage to sense an upshift and kill ignition for a few milliseconds is all it takes to keep them from blowing apart.

and yup.. easy to do on any bike at normal speeds.. i typically use this on all my bikes simply because i'd rather get as much out of my consumable components as i can. i'd rather ride and not wrench!

with drag raching and high-output bikes, clutchless is almost nesessary when utilizing a lockup clutch. the centrifugal force generated by the lockup assembly's weights is far greater than the pressure you can usually generate squeezing the lever in.. ppl have snapped levers and cables and bent pushrods and blown lines thinking they can manhandle a lockup.. lol
they behave like normal tho when on the throttle easy and at low rpms.
 
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Old 12-23-2008, 02:11 PM
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good info there whitehendrix
 
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Old 12-23-2008, 05:54 PM
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I used clutchless upshifts when I raced without any problems ever. Even used the same clutch for over 2 seasons!
 



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