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What kind of force would a solenoid have to have to change fireblade gears ???
tompat3463 - 17/8/11 at 10:10 AM

as the title really.. I'm thinging about trying to develop a fireblade electric gear change sytem but need to try and find out what sort of force would be required ??

or a method of finding it out...

was thinking somewhere in the region of 1000gf ?? does this sound about right ???

cheers Alan


coyoteboy - 17/8/11 at 10:20 AM

Don't know about that box specifically but:

It depends on the leverage you're using to rotate the shaft. Assuming you have a lever you're going to use, get a spring balance and measure the force required to shift the gear home nicely at a specific point on the lever. Now multiply by about 1.5 for safety (but it'll shift easier while running). Now find a double pole solenoid that has the throw required and force needed to shift both ways.

On a CBR600rr with a lever length of about 100mm about 50N is required with a throw of about 40mm in each direction.


tompat3463 - 17/8/11 at 10:28 AM

ah cool.. thanks mate.. so about 5kg of force on 100mm lever with say 50mm throw would do it ???


tompat3463 - 17/8/11 at 10:42 AM

also....U got any links to where I could get an actuator from ??

cheers Alan


tony-devon - 17/8/11 at 12:08 PM

try getting a look at any bikes or trikes that are fitted with klik tronic, might be able to get a part number from the actuator??


coyoteboy - 17/8/11 at 01:50 PM

The klik part is apparently custom (we've spoken to them) and not cheap. We wound our own but it's not idea and quite bulky. RS or Farnell will have lots of solenoids but few have the sort of force/stroke requirements you want (as we found) and will be expensive. It's actually cheaper to buy the kits from what we saw.

Instead, I'm working on something better but it's hush hush for now


sprouts-car - 17/8/11 at 01:56 PM

What about pneumatics?
Its a tried solution and should be cheaper than a solenoid.


JF - 17/8/11 at 05:28 PM

Don't think pneumatics would really work well in this situation. You'll need a fairly large stubby cylinder to produce enough force, or a long thin one with a long lever. You'd also need some beefy springs to get the lever back to the 'home' position, as regular pneumatics is really lousy at stopping midway (without load).

And also... where would you get your air from? You'll need a motor driven or electric compressor in the car.

If you would get it working, then there is the matter of reliability... I've got bad experience with ordinary pneumatics on vehicles. Purpose build like brakes and suspension on trucks and lorries seem to hold up quite well, but every once in a while...

No I really do think electronic is the way to go. The 2 way, long throw, specific power combination might be hard to find though. And try to set it up so that the actuator is at the end of its stroke together with the end of the stroke of the lever. Bike boxes don't like to be handled rough...


TRX - 29/8/11 at 08:35 AM

I had a Dale Walker electric shifter on my Suzuki Bandit. It was a drag race kit, upshift only. It used a cable and a solenoid' the solenoid looked like it came off a car starter.

The kit also came with a programmable ignition interrupter to kill the spark during the actual shift. You set it so it shifted smoothly at WOT. The shifter didn't work very well at part throttle.