Clutchless shifting?

[SMOKEU]

I always use the clutch to up shift from 1st to 2nd gear, and I always use the clutch for downshifts. For the rest of my upshifts I find it much easier and smoother to upshift without using the clutch.

Since I can shift significantly more smoothly without the clutch I don't think I'm doing the gearbox any harm as it never crunches or makes any strange noises when I do clutchless upshifts, and it shifts with very little effort.

[TrentNz]

sometimes I do sometimes I dont, depends upon how hard im pushing the bike.
I would say I use the clutch 70% of the time.
I have not yet broken a gearbox by not yet using the clutch.
Out of interest, I use to do clutch less gear changes in cars up and down successfully
I find cars are smoother than bikes to do this once you learn how.
Truckies very often do clutch less changes
Older trucks you only ever used the clutch to get you moving
Those who have ever driven a ACE, Tatra or a Austin Mastive will know what I mean

Ahh, my dad is an old truckie, only uses the clutch to take off and stop.
yes the clutch is their and yes you should use it, but at the end of the day when you don't you're saving wear and tear on your clutch plates etc.

[Ender EnZed]

Truckies very often do clutch less changes
Older trucks you only ever used the clutch to get you moving

Ahh, my dad is an old truckie, only uses the clutch to take off and stop.
yes the clutch is their and yes you should use it, but at the end of the day when you don't you're saving wear and tear on your clutch plates etc.

Yeah, but on old trucks the only other option is double clutching anyway.

It'd not really a fair comparison to a bike.

[gatch]

Upshifting with no clutch is a cynch. A brief throttle closure will make it work well. Unless the bike is cold.. Down shifting I will always use the clutch and blip the throttle to match rpm.

[Gremlin]

Here's a link to a thread with lots of links in it discussing the topic... tempting to lock this thread as well...

http://www.kiwibiker.co.nz/forums/sh...hless-shifting

edit: Threads have been merged instead.

[ducatilover]

I used to do it all the time, shifting up/down everywhere and never had a gearbox issue.
I stopped doing it on my CB400 just because I figured there was absolutely no point in me doing it and never did on the 600 (has a terrible box anyway)

[Drew]

The purpose of the clutch is to disengage the engine from the gearbox. When shifting gear, this purpose is served by unloading the gears, allowing them to shift into the next meshed position. If judicious use of the throttle can achieve the same effect of unloading the gears, then why not clutchless shift?
Going up is easy, but few if any of us ever achieve a good result when going down.
(Did I just say that?)

Bikes don't run syncromesh gearboxes. All gears are meshed all the time, but only every second gear is attached to it's spline all the time. With a "dog box" when you shift gears you are actually attaching a free spinning cog to the side of a fix one.

The extra wear of clutchless shifting is on the "dog", where the edge of the dog teeth get rounded a bit, and the slight taper on them wears down. Once that happens the bike will "jump out" of that gear repeatedly. Common on a few bikes, (RF 900, ZX6R to name a couple), and completely unheard of on most bikes. If this happens, avoid precision grinding and have it spark eroded. Grinding can bugger up the hardening because of the heat generated.

Ps, always use the clutch from first to second gears. Because of the extra selector barrel movement between them the shaft speeds can get a greater differential and the dog/cog will slap together hard.

[steve_t]

Ps, always use the clutch from first to second gears. Because of the extra selector barrel movement between them the shaft speeds can get a greater differential and the dog/cog will slap together hard.

Yep, I always clutch for 1-2 cos of that pesky N in between

[Drew]

Yep, I always clutch for 1-2 cos of that pesky N in between

On your bike, unless you're absolutely caning it, use the clutch. The gears have a five point contact on the ZX6 dogs, and from what I've heard, less than all of them actually make contact when the gears are engaged.

Jay Lawrence had to have his whole gearbox matched and 'back cut' (which is a steeper taper where the dog and cog engage), to stop it jumping back down a gear after changing.

[ducatilover]

On your bike, unless you're absolutely caning it, use the clutch. The gears have a five point contact on the ZX6 dogs, and from what I've heard, less than all of them actually make contact when the gears are engaged.

Jay Lawrence had to have his whole gearbox matched and 'back cut' (which is a steeper taper where the dog and cog engage), to stop it jumping back down a gear after changing.

Seems like the ZX6 Kwaks have always had weak boxes. Mine is prone to eating the dog (must be Tongan?) for 2nd and a few other little minor bits and bobs...like the shift drum and stuff...

[Drew]

Seems like the ZX6 Kwaks have always had weak boxes. Mine is prone to eating the dog (must be Tongan?) for 2nd and a few other little minor bits and bobs...like the shift drum and stuff...

Get a buggered one spark eroded, guy here in Wellington only charged me $150 to match my second gear dog and cog. Replacing it with OE new ones is just waiting for it to happen again.

[awa355]

On a sports bike gearbox, clutchless shifting works, ( we used to do it back in the 70's) but I wouldn't want to try it with the 'Agricultural' gearbox on my cruiser.

Don't Motogp bikes have a clutch? as well as the push button change mode?

[Drew]

On a sports bike gearbox, clutchless shifting works, ( we used to do it back in the 70's) but I wouldn't want to try it with the 'Agricultural' gearbox on my cruiser.

Don't Motogp bikes have a clutch? as well as the push button change mode?

GP bikes have clutches, they're required for down shift on the brakes.

The gearbox on your cruiser is just as strong as a lot of sports bikes. But it's a low revving twin, so it'll seem quite abrupt if you shift without the clutch, for no real gain.

[MSTRS:Me]

Bikes don't run syncromesh gearboxes. All gears are meshed all the time, but only every second gear is attached to it's spline all the time. With a "dog box" when you shift gears you are actually attaching a free spinning cog to the side of a fix one.

The extra wear of clutchless shifting is on the "dog", where the edge of the dog teeth get rounded a bit, and the slight taper on them wears down. Once that happens the bike will "jump out" of that gear repeatedly. Common on a few bikes, (RF 900, ZX6R to name a couple), and completely unheard of on most bikes. If this happens, avoid precision grinding and have it spark eroded. Grinding can bugger up the hardening because of the heat generated.

Ps, always use the clutch from first to second gears. Because of the extra selector barrel movement between them the shaft speeds can get a greater differential and the dog/cog will slap together hard.

Yea, I sorta knew all that. Just easier to understand when put in terms of 'loaded' or 'unloaded'...under acceleration or engine braking, it is (next to) impossible to change gear. It is only when the clutch is used, or a quick flick on or off of the throttle, that you can slip into the next gear.

[steve_t]

On your bike, unless you're absolutely caning it, use the clutch. The gears have a five point contact on the ZX6 dogs, and from what I've heard, less than all of them actually make contact when the gears are engaged.

Jay Lawrence had to have his whole gearbox matched and 'back cut' (which is a steeper taper where the dog and cog engage), to stop it jumping back down a gear after changing.

Oh, cheers, good to know!