Clutch-less downshifting.

[onearmedbandit]

Due to the set-up on my bike, which while being quite good is now showing some shortcomings, hard front braking, blipping the throttle and clutching while downchanging is affecting my approach to corners, mainly on the hills where its twisty and a lot of accel and brake action. Gripping the brakes with two fingers, and using my thumb to flick the clutch and blipping the throttle means that the pressure I'm exerting on the brakes varies, upsetting the front end.

Now I'm trying to pratice steading my braking fingers, but my hands are not overly big so its stretching it already. So anyway, I resorted to a method I'd used before, but not on this bike, which is blipping the throttle the right amount, at the right time, and downshifting without the clutch. I can execute this with no drivetrain snatching or backlash, it enables me to steady the bike better for my entry making for a smoother faster corner.

So until I can come up with an alternative method for the clutch (I thought of many and been offered a few. Please, no one talk about puting the clutch where the rear brake is. Think about it, thats what I've told everyone who has suggested it.) I think, under harder riding conditions, I'll stick with this method.

Now, I have previously been told by a couple of people that it is not possible to execute a clutchless downshift without inflicting major damage to your gearbox, shortening its life dramatically. My arguement is that with no pressure on the box (from blipping the throttle) there should be no damage done, as releasing the pressure from the 'box is essentially what a clutch does. Sure, if you fuck up its not so good, but I seem to be able to nail it. With light pressure on the lever, the gear will 'fall' into place. I mean very light pressure. So, can anyone here offer a experienced opinion on this method, do you use it, any damage to your gearbox?

[moko]

I`m not technically gifted enough to figure out how but couldn`t you somehow integrate your clutch switch with your gear lever?Maybe even get something rigged-up like the old "heel and toe" gear levers so your heel operates the clutch while your toes operates the gears,that way with a bit of practice you could still do clutchless up-changes if you wanted to.I`m not sure about clutchless downchanges,sounds like a good way to lock your back wheel up if you get it wrong plus I`d have thought all kinds of strains on your transmission.

[What?]

I`m not technically gifted enough to figure out how but couldn`t you somehow integrate your clutch switch with your gear lever?

That has been done, I think by Triumph (definitely one of the pomgolian makes), late 50's. If set up parrallel to the bar-mounted clutch lever, it should work well.

[Motu]

The Triumph Slickshift,Jawa had it on several bikes and the Nzeta,and of course the Honda stepthroughs,I'm sure I've ridden other bikes with a gearlever/clutch combo but can't remember offhand.It'd be kinda hard to do it to a modern bike,it'd have to be external with cables...but not impossible,I'm sure someone has done/could do it.Lots of cars get set up for disabled drivers,various ways it's done to suit various disabilities - maybe a talk to the guys who do the conversions.

I see no problem with clutchless downshifting,it's done with dirt bikes all the time and I often do it on road bikes,it's just a matter of getting it right everytime.Bikes have a dog gearbox,same as crash boxes on trucks - I often drove without a clutch in the older slow reving slow shifting trucks,in fact some you couldn't even use the clutch...on the old Atkinson you could use the clutch for reverse and 1st,then the gearlever was in the middle of your leg,there was no way to use the clutch.

[**R1**]

hey bro, i shift down all the time without the clutch, it doesnt seem to be any harder on the box....i have been doing it for years and never trashed a box, also perhaps a slipper clutch would ease things up a little you can get them for most bikes....not sure on price tho???.....the only other thing i can think of is to use electronics the same as a quick shift where as you change dwn it cuts the engine for a fraction os a second to unload the box?? give me a call or pop over im sure we can think of something.

[vtec]

Hey, interesting issue. I had heard that motogp bikes (this could be wholly innaccurate) used a clutch that was incorporated with the gear lever so that it disengaged the clutch just before it changed gears, and I think I have seen a kit for road bikes which uses the same idea. I think you could possibly rig up one by yourself if you're clever. Also note that I only say possibly, cause I haven't looked at how much the clutch needs to move to disengage/re-engage. Good luck, tell us if you find a way to do it.

[dangerous]

OMB: I had a quick look at the KTM the dude in Chch races at Nelson port, and his clutch was facing down so he did a ralativle normal take off then rotated his hand so as he could brake the ususll way, that make sence.

[TwoSeven]

I dont blip and I use half clutch technique for changing gears (both up and down), I often go down multiple gears at a time and use the clutch to feel what the engine does.

There is no right or wrong technique, but one thing about clutchless shifting - it wont damage your clutch, but a bent gear selecter is fookin expensive

Last I heard some race bikes use a quick shifter triggered off the foot lever - but its normal for riders to use the clutch lever when more feel is required. The clutch isnt just used for changing gear - its important to also learn how to control the bike with it.

[Slingshot]

Here's a possible solution:

Hook up a solenoid to the end of the clutch cable with a small push button switch mounted in the top on the gear change pedal.

I'm not sure what force would be required to engage/dis-engage the clutch by you could probably measure that easy enough and just get a solenoid to match the force required.

When you put your foot on the gear pedal the clutch would engage, push down further to change the gear and as you lift your foot up off the pedal the clutch would disengage.

You could also rig up a second button on your clip-on, this would mean you could cut the clutch cable short and hide the solenoid contraption under the tank.

[Slingshot]

Just another thought...the push button and solenoid couldn't just operate in either all on or all off mode. Otherwise gear changes would be rather dangerous (wheelies all the time )

If you could find a switch that measured the amount of pressure (maybe some form of a varible resistor) and a solenoid that would extend/retract a certain distance depending on the voltage it was receiving.

That would work, I'm sure of it.

[onearmedbandit]

Thanks for the ideas guys, keep them coming. Aaron, yeah I'll pop over when I get the chance, see what we can come up with.

[Rainbow Wizard]

No, not a typo. Makes sense to me to rig it up so that your jaw drives the clutch. Even though it would mean you'd need to link your helmet with a wire or flexible tube. There's well enough pressure able to be exerted in a controlled fashion by the jaw. You even have the choice of having it between your teeth and adding a flavour to the device. Sweet as shiftying here we come.

[StoneChucker]

I haven't read the replies, so apologies if this has been covered.

On http://www.ciamotorsports.com.au , under the '04 R1 section anyway, check your bikes manufacturer, they have clutchless powershifters. I'm not sure what they use, gas, or whatever, but that might solve your problem?

*EDIT* On the above site, under your bike:

MPS Sportbike Auto Air Shifter Complete Kit

MPS Sportbike Autoshift setup..! For FULL throttle... Clutchless shifting.... AUTOMATICALLY! Click on picture for details. This kit includes the shift chips, air compressor & horn wiring harness
$1,000.00

Thats the complete and full system, there are cheaper ones, and possibly different makes?

[pete376403]

Killing the ignition momentarily is enough to unload the gear dogs and allow a smooth shift to happen. A press button type kill switch would be enough. My dad told me he did this waaay back when, with a kill button on the magneto of his bikes. Possibly the origin of the term "button off" referrring to closing the throttle/slowing down (but not stoppng)
Or you could ride a Suzuki - they have buttery smooth gearboxes that let you get away with all sorts of abuse.

[Gixxer 4 ever]

So, can anyone here offer a experienced opinion on this method,

I do not race on the track so maybe this is a different situation but I ride a 97 GSX-R 750. I seldom use the clutch to change down. Most of my up changes are clutch less as well. When I need to change down, going in to or in a corner, I unload the box by dropping the revs a fraction. Now this works when you are running 6-8 k and over on the rev counter. As soon as the throttle drops 1k or so it just drops in as smooth as silk and you are back on the gas hard to drive around the corner. If you are just cruising below 5k then you some times need to us the clutch but most changes are silky smooth without.