Clutchless upshifting?

[samgab]

Hey there. I'm fairly new back into motorcycling, with a past of riding farm bikes, trail bikes, and very small motorbikes that *needed* to be fanged hard.

What is the general consensus on clutchless upshifting?

For the first couple of days I was using the clutch for every shift, but now I've gotten back into the habit of clutchless.... It's so much faster and smoother -- when you get it right.

Does it cause any excessive wear and tear on the gears? It doesn't seem to. When you preload the gear lever a little and just blip the throttle a bit it's almost instantaneous.

So do you use the clutch for upshifts?

http://www.sportrider.com/ride/146_0...ing/index.html

[Katman]

Yes it certainly can cause accelerated wear.

Using the clutch removes the pressure exerted on the gear dogs while they slip out of contact. Repeated clutchless shifting (especially when pre-loading the gear lever) often results in your bike jumping out of gear.

[Maki]

If you do it right, then clutchless upshifting is a great way to shift. Fast, smooth and does no harm.

http://cbrforum.com/m_690211/tm.htm

"I''ll point out that the type of transmissions used in motorcycles is completely different from a car transmission and clutchless shifting poses no threat of damage. In fact using the clutch causes more wear! (to the clutch plates)"

http://forums.sportrider.com/70/6232...ion/index.html

"Something you might want to try that I found was pretty neat fun. I own a K6 Gixxer Thou'. While I don't usually ride childishly, recently I was bored and wondered whether the soft rev limiter wound allow a quick clutchless up-shift when it hit it. The answer is a resounding yes. Once you get past the looping point, preload the shifter and get it wide open in first. When it hits the limiter, you will get a perfect, ultra-fast shift into second (at an indicated 105 yet!). It'll pop up a bit and continue it's rocketship forward motion. 2nd to 3rd is almost as exciting. Had to shut down after that, very few places to hit 150 around here. Great fun. Enjoy the ride. Cheers, jack"

[Katman]

Fast, smooth and does no harm.

Oh, ok. Maybe I'll just sell my workshop and take up floral arranging instead.

[hospitalfood]

dont do it myself, i think plenty of people do but.
tried it a couple of times but i find i can change fast with the clutch so stuck with that.

[cs363]

If you do it right, then clutchless upshifting is a great way to shift. Fast, smooth and does no harm.

http://cbrforum.com/m_690211/tm.htm

"I''ll point out that the type of transmissions used in motorcycles is completely different from a car transmission and clutchless shifting poses no threat of damage. In fact using the clutch causes more wear! (to the clutch plates)"

http://forums.sportrider.com/70/6232...ion/index.html

"Something you might want to try that I found was pretty neat fun. I own a K6 Gixxer Thou'. While I don't usually ride childishly, recently I was bored and wondered whether the soft rev limiter wound allow a quick clutchless up-shift when it hit it. The answer is a resounding yes. Once you get past the looping point, preload the shifter and get it wide open in first. When it hits the limiter, you will get a perfect, ultra-fast shift into second (at an indicated 105 yet!). It'll pop up a bit and continue it's rocketship forward motion. 2nd to 3rd is almost as exciting. Had to shut down after that, very few places to hit 150 around here. Great fun. Enjoy the ride. Cheers, jack"

Just because some twat posts information on an internet forum does not make it gospel! (feel free to apply that rule to this and all other posts in this thread)

As most modern motorcycles have a sequential gearbox you can reasonably safely shift clutchlessly without any undue wear if you employ some mechanical sympathy - that is backing off a tad as you would if changing with the clutch. If you want to flat shift you certainly can and it is fast - but ultimately this will cause accellerated wear.
The best thing if you really want go down this road is to get a quick shift kit which will usually include a 'black box' that will momentarily cut the ignition, providing the above mentioned mechanical sympathy automatically.

[cs363]

Oh, ok. Maybe I'll just sell my workshop and take up floral arranging instead.

The Katana would look lovely surrounded by pansies....

[Reckless]

All I can tell you is for many years Kart racing 125 and 250 2strokes (MX engines) on petrol, avgas and methanol. Covering Kawasaki, Yamaha and Cagiva engines we never even had clutch baskets. The clutch Basket and plate removal were one of the first mods we did. Only cog left in that side was the power valve drive. I don't know of many failed gearboxes, I never had one. Think about a gearbox kart and how many times per lap you bang it very quickly down a few gears going into a corner then up again etc. We gave them absolute hell. Mind you we where racing if your doing it for laziness you "rep what you sow".
I find myself doing the same on my MX bike but I must admit I use the clutch on the old Z1R.
The trick was to come off throttle for the split second it takes to change, if you try to pull it through under power I think you will cause damage.

My 2c

[Katman]

And pre-loading the gear lever initiates the process of gear dogs sliding apart but does so while full load is imparted upon the dogs. Eventually instead of two 90 degree mating surfaces the gear dogs wear at a slight angle thereby causing the gears to naturally want to force themselves away from each other under heavy acceleration.

[cs363]

And pre-loading the gear lever initiates the process of gear dogs sliding apart but does so while full load is imparted upon the dogs. Eventually instead of two 90 degree mating surfaces the gear dogs wear at a slight angle thereby causing the gears to naturally want to force themselves away from each other under heavy acceleration.

Agreed - hence my 'twat' comment on that US forum posting.

Clutchless shifting as I outlined above isn't too bad all things considered, but pre - loading the gear lever is a definite no-no.

[Katman]

The Katana would look lovely surrounded by pansies....

And before anyone suggests it, he's not talking about just when I'm sitting on it.

[cs363]

And before anyone suggests it, he's not talking about just when I'm sitting on it.

Err.... sitting on what Katman??!!

[Reckless]

Same, We never pre loaded the gear lever in the kart, you couldn't really unless you hand a hand on the gear lever all the time and that was impossible and I don't on the MX bike either? Only pull it through when the power is off!

[samgab]

Thanks for the feedback so far. Seems like there are opinions on both sides, and for my part, I think I'll use the clutch most of the time. It can't hurt to use it anyway.

[Maki]

Sounds like it's ok, as long as you don't pre load the lever. Did you know that many race bikes have a system that allows clutchless upshifts? It makes the throttle back off automatically when the gear lever is pushed up.