Questin about clutchless shifting?

[PhantomDgn]

ok. I've been readin on alot of fourms asking if people preform clutchles shifts.  My question is  is a clutchless shift good for the bike? or is shifting  (like on a car) the best way to go? (roll off, clutch, shift, roll/release clutch)

[Hawk]

Maybe the question should read, "How much is a new tranny?"

[hotshoe]

If you can pull a clutchless shift so smoothly that you (or a passenger) can't feel it, you probably aren't hurting the tranny much. If, however, there is even a slight lurch, then at best you are shock-loading your drive train - not a good thing, from end to end - and at worst, well . .  BANG! Bits of your bike, and in the very worst case, bits of you will lay on the road, waiting for the street sweeper.

[Scott]

Always clutch, man.  If your bike was designed to clutchless shift, there wouldn't be a lever on the left grip.

If you're into racing and your track time is more important than the cost of a new transmission.... maybe a clutchless shift is okay.

[Bernie]

There is NO WAY that clutchless shifting is as shift fork friendly, as gear friendly as clutch shifting. All the little hits on the engagement parts of the transmission add up. No problem when you only own or race it for a year.
Don't be so lazy!
Seriously, at least take most of the load off by pulling in the clutch most of the way before you jam the lever.

[Hawk]

The only way a clutchless shift works without a high risk of severe damage is with the old truck "crash boxes".  There were no synchro rings and the gear face teeth were very large and wide.  Once you got the beast moving, you could throttle the engine back to take the pressure off the gears, adjust the engine speed up or down, and genltly slide it into the next gear.  I remember being able to shift both trannys at the same time ... sometimes!  But, as Mark said, if you felt even the slightest lurch, you were putting a great shock-load on the whole drive train.

A motorcycle transmission is a whole different thing though.  Most of them are now constant mesh, which means that the gears remain engaged at all times.  Shifting is accomplished by engaging dogs to the side of the gears. When you do this under load, and there is almost no "false neutral" between the ratios, you bash and chip the engagement dogs.  Metal bits floating around in the tranny can get swept up in the oil between the gear faces and you have an instantly split tranny case.  The rounded off dogs are very prone to slipping out of gear and, if you're up at max revs, that usually means a spectacular blow-up. All of these things mean BIG DOLLARS to fix.

So, unless a few milliseconds is worth the risk, and the bike is a "one race throwaway" - pull the clutch. Even just a little ....

[2wheeltim]

I find this thread very interesting and could be alone in my view here.  I've never used my clutch for shifting past 2nd gear.  Obviously I use it to start off, slow speed maouvering and I give it a little blip in between 1st and 2nd to ensure passage through the dreaded 'N' shift+rev(embarassing).  Well those of you who know me, know I also used to use it to raise the front wheel from time to time.  The interesting thing here is why I started this.  I scared myself shifting with the clutch a little to early coming out of a corner and had to recover from a high side pitch.  It takes practise for sure but I can guarantee once you have it, you'll shift smoother without the clutch everytime.  And I can shift even in an aggressive corner without problems.  

For those of you now nervous about your tranny from the past posts, I've put 40,000 kms on a 98 CBR600, 65,000 km's on a 00 CBR 929 and 10,000 kms on a 01 RC51 (once you ride twin you don't go back).  Now I've got a 00 VTR1000 but I've only put a couple thousand on it.  I've never had a problem with any tranny, but I also have my own rigorous maintenance schedule.  For long engine/tranny life the best thing to do is a proper warm up, especially on these tight tolerance engines, but that's a separate thread.  I love the guy who hops on starts it at half throttle and takes off!

So for those who want to do clutchless shifts, I found the key is to let the throttle do the shift for you.  Apply slight pressure to the little shifty peg thing there and roll off or on as required to unload the tranny.  The next gear will fall in cause as Hawk mentioned the tranny is a sync mesh (all gears are turning except reverse )  Oh wake up!  When you're learning, downshifting will be harder so a slight blip of the clutch is sometimes nice, but you don't need to completely disengage.

I actually learned this technic driving highway tractors (Kenworths) where you slip it into neutral rev up or down as required and 'tickle' the gears till they mesh.  Truck drivers generally don't use the clutch.

Well, let the attacks begin!!

Tim

[waypastfast]

I shift up with out the clutch all the time. We have what are called constant mesh transmissions. They shif fine upward just fine. Just do not downshift them that way. When you up shift you pull up lightly on the shifter and then give the throttle a quick blip down. Shifts perfectly everytime.

Scott

[2wheeltim]

Yes upshifting is easier, but as I said downshifting is possible too, but requires a little more control of the trottle and feel for timing.  Usually I'm downshifting to either grab more power for a corner or to slow down, so when I go to downshift I usually get off the throttle, put slight pressure down on the peg and slowly roll on.  The lower gear slip right in as the engine slightly accels and then you can be back off the throttle.  Once you get the hang of it, it all happens in a blink.  At first it seems like you have to really concentrate on the throttle, and your going up and down a lot, but it comes.

Regards,

Tim

[2wheeltim]

I also wanted to add that this is no harder on a tranny than shifting from 1st to 2nd with the clutch.  That shift through neutral, and also normally the largest ratio gap, is the hardest on the dogs.  These are always the first to wear out.

Tim

[Robert]

I also wanted to add that this is no harder on a tranny than shifting from 1st to 2nd with the clutch.  That shift through neutral, and also normally the largest ratio gap, is the hardest on the dogs.  These are always the first to wear out.

Tim

I can confirm that Ruined my v-max trany by doing wheelies in 1st and shift her up into 2nd while on the rear wheel. However it was fun, and the max was to heavy to get her up in 2nd.

However it ruined my 2nd and 5th gear at the same time at the v-max. Don't know why. Bog told me they are somehow always going together, his v-max as well had the 2nd and 5th die at the same time, even he didn't do any wheelies, just lots of hard acceleration. LOL

Now I usually if I do wheelies I just use one gear and just power them up. some in 1st and some in 2nd.

[2wheeltim]

The reason there are always two gears that go is there are always two or three on the same shaft, then the ratio changes by sliding an idler shaft along inbetween these paired shafts.

Tim