Air shifter??

[Clyde the ape]

What is an air shifter & how does it work.  I am throwing around the idea of building a street / strip bike.

[Piute]

Air-shifters use high-pressure air from a storage bottle to shift the gears of a vehicle when triggered by a button controlled by the driver. Special sequential transmissions are used for air-shifter applications. At the instant of the shift, power to the engine is also cut so that the clutch is not required.

Air-shifters operate more quickly and positively than you can using your arm (car) or foot (motorcycle). They are used almost exclusively for racing applications where saving a few milliseconds can be the difference between a win and a loss, and where a missed shift can result in a $pectacular engine di$a$ter. Imagine the brief but intense experience of sitting straddled on top of a disintegrating 1000+HP pro-stock motorcycle engine, running wide open in neutral, while traveling at 150mph...

[Clyde the ape]

So then I guess I can't use one on the street?  

[shinyribs]

And they only upshift. You have you  downshift yourself.

[Piute]

   Harley-Davidson VRXSE Screamin' Eagle V-Rod Destroyer
 This is the only bike I've seen(2006) personaly that has a push button shift ,
   Its transmission has been modified by Andrews Cam and Gear, cutting the number of cogs in half and undercutting the gears for quicker and easier shifting via a really cool push-button air shifter system.            

[shinyribs]

Hey Clyde. Sorry for not giving much info earlier.I was on my phone and didn't feel like typing a bunch on that little thing.

Air shifters are sooo cool!

Basically you mount a cylinder (looks like a miniature fork tube or steering damper) on your frame somehow and it attaches to your shifter pedal. That cylinder works off of compressed air. Kinda. Most guys run CO2 since the moisture in simple compressed air can cause rust and oxidation issues inside your cylinder. Other guys use nitrous oxide if CO2 is not available.The CO2 or NOS is in another storage tank that has to be mounted somewhere as well. There is a vale mounted inline between the CO2 (or NOS) storage tank and the shifter cylinder. There is also a handle bar mounted switch to activate that inline valve. The handle bar switch and valve are 12 volt items. When you hit the handle bar button it opens the valve (valve will stay open until you release the button) allowing the pressure to activate the shifter cylinder.It simply pulls the shifter up into the next gear when you hit the button. keep hitting the button and it'll keep shifting. But it has no means to ever downshift by use of the airshifter. You CAN still ride and shift gears normally with the air shifter on the bike. Yes.it could be done on the street as long as it can be mounted so as not to interfere with anything.

There is no reason you could not mount another shifter cylinder to create downshifts,but you never see that done.

There are some older kits that require no 12 volts or ignition cut-out. On those kits the handle bar switch is actually the inline valve it self. Since you are dealing with high pressures (could be as high as 800-1,000 psi) it can be hard to push,but its do-able. Thoce kits have basically gone the way of the do-do,as far as I know,but you ever found one I would run it in a heartbeat!! There are way cool!

Everything Piute is accurate as well,especially the part where it kills ignition momentarily to allow a clutchless shift. By killing the ignition and refiring it you will get an occasional back fire which is not a big deal on a un-muffled drag bike,but can pose some problems on the street. Like tossing your muffler,or its guts,onto the curb. But It would be worse case scenario and you would either have to stay on the button for an extended period of time(allowing additional raw fuel to build up)or have the bike jetted rather rich to begin with. Under normal circumstances it should perform without you ever noticing the momentary ignition cut-out.

I dont know about the bike kits,but the air shifters used on our drag cars will typically give you 200-250 shifts per 2lb cylinder of CO2 or NOS.Provided you dont have any leaks and remember to turn the valve off on the cylinder when not riding. The line kits are NOTORIOUS for slight leakage,no matter what you hear.It will leak.

An air shifter on a bike is 100% street-able and I think it would be waaay cool!

Hope this helps.