gearing for a 570 please?

My thoughts zaccary cuzzie bergbro
holy fark this thread has gone proper sideways and thats after .5 litre of queensland diesel. :lol: :lol: Things are jumpin again Jussfuggenridethakharn. and futhermore geddadeaddogupya. Conversely. shave 100 thou off the thruppit (TM) bearing and add a brigde rectifyer the flux capacitor, that sould produce gyroscoptions at the golden ratio. :drinking:

Like, dont get me wrong boys. Im not saying mass centralization is not needed as it surly is, but the degree of gyroscopic effect the cranck has is going to be constantly changing dependent on throttle position, bike attitude, axle position and a whole lot of other influences so to find the absolute corrrect position is gunna depend on intended use of machine, rider ability etc etc.
aarrrrggggghhhhhh. this is getting far to serious. i better go back to work.

And to answer the original question, try 8-108 it has a nice symmetry to it. Should reflect the score of the next Lions Oz test :bounce3: that we win.

Coming to see it Taffy?

:cheers: :cheers: :cheers: :cheers: :cheers:

the point of this stuff is.. none of it really matters. you just make the best of what you have in front of you and ride the pants off it. quite glad everyone gets that bit.

also pleased some can be bothered to put some thought into what might really be going on. it looks like nationality wise we're all supposed to have an unhealthy reaction to lanolin. begs the question; is the site healthy coz we're unhealthy

steve I remember the honda and the cog changes, they said at the time another issue was weight transfer to the front during braking.

the wheels bergsmlerg yes if you work out the mas moment of inertia they have more effect gyroscopic wise at 30km/hr than the crank at idle

it doesn't matter where the pivot point is for leaning, the point i wanted to bring up was that gyroscopic inertia only has any effect if the bike rotates in the horizontal plane as it does on corner entry.

when that happens the resulting gyroscopic force helps you tip the bike over. thats was it, very simple.

Gyroscopic precession to be more precise.

The other thing happening when initiating a turn is related to 'countersteer, or 'outtracking'. When travelling in a straight line on a flat surface, to keep it simple, to iniate the turn, the front wheel initially points in the opposite direction. This means that, to say go left, the wheel initially steers right. This is easiest to remember by pushing on the left bar to go left and the right to go right. Must happen, no choice, but usually combined with hip, knee, peg pressure to assist and the rider mostly isn't conscious of it.

Once the front wheel is pointing the wrong way, the bike is still trying to go straight ahead, and starts to roll around its CoG, resulting in a lean in the desired direction. Relax the pressure on the bars and the wheel falls into the desired direction due to the trail, and you proceed as desired. If not, crash. Happens to all single track vehicles over a certain speed, say 20 kph for motorcycles. Note that it rolls around the CoG, not the tyre contact patch.

You all do it, and did ever since the training wheels came off.

Clear as mud?

Gets more complicated with dirt bikes because we deal with more ruts, berms, cambers etc than the roadies, and I'm ignoring brake sliding to set up too.

Steve

steve said:

The other thing happening when initiating a turn is related to 'countersteer, or 'outtracking'. When travelling in a straight line on a flat surface, to keep it simple, to iniate the turn, the front wheel initially points in the opposite direction. This means that, to say go left, the wheel initially steers right.

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Reminds me of Simon, that boy needs a wood router for Christmas :lol: :lol:

that pic illustrates it perfectly

you step the back out as steve described then the axis of crank that used to be travelling in a straight line doing nothing gyroscopically has now rotated in the horizontal plane as the back of the bike steps out.

the cranks reaction however small is to help tip the bike over in the vertical plane

We need to sit down and consume a slab or 2 to get this properly worked out. I was trying to leave out backing it in to simplify the discussion, whatever. TGIF

steve said:

What happens when turning is the the tyre contact patches move from under the bike as the bike rotates about the CoM/CoG. Watch the bikes racing the GPs exit a corner, the tyres are out towards, or on, the edge of the track and as they straighten and stand up, they rotate around the CoG and the tyres move back under the bike, away from the edge of the track, leaving an S shaped path.

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I'm not convinced that's right.

Before a tyre slides, the bike rotates left/right about the contact patch of the tyres. Once the tyre is sliding, the axis of rotation will be somewhere the between the CoG and the tyre contact patches (according to what forces (ie 'grip' the tyres are able to offer).

steve said:

The other thing happening when initiating a turn is related to 'countersteer, or 'outtracking'. When travelling in a straight line on a flat surface, to keep it simple, to iniate the turn, the front wheel initially points in the opposite direction. This means that, to say go left, the wheel initially steers right. This is easiest to remember by pushing on the left bar to go left and the right to go right. Must happen, no choice, but usually combined with hip, knee, peg pressure to assist and the rider mostly isn't conscious of it.

Click to expand...

Precession and counter-steer comes about through the application of a force to the bars - not a movement. There is no intial steering right before turning left. As soon as a force is applied by pushing the left bar (or pulling the right bar), the precession effect is that there is movement in the gyroscope (wheel & tyre) at 90 degrees to the force - ie the wheel/tyre lean to the left - and hence the bike turns to the left.

steve said:

Note that it rolls around the CoG, not the tyre contact patch.

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I think you need to rethink that. It's like saying that a clock's pendulum swings about its CoG when it actually swings about its pivot point.

Greg

it doesn't matter where the pivot point is for leaning, the point i wanted to bring up was that gyroscopic inertia only has any effect if the bike rotates in the horizontal plane as it does on corner entry.

when that happens the resulting gyroscopic force helps you tip the bike over. thats was it, very simple.[/quote]


I thort the gyroscopic force would be inclined to prevent the bike from tipping into a corner due to the gyroscopic forces keeping the wheel goin ahead..... hence road racers have little wheels on the front to reduce the gyro effect and make changing direction quicker/easier.

digressing marginally but still in a simalar vein..... do 390 bergs change direction easier than 570's (all other factors being the same) because comparing 450 to 650's, 450's seem to be easier to change direction on than the bigger (not really) brother when the only difference is a couple of mm's block height.... so does the greater mass of 650 piston reciprocating at 133 times a second have a greater gyroscopic inertia effect than shifting the head 2mm heaven side (up), hence my question about the 390/570.
By having the inertia moving in the same direction as bike motion does this cancel out the main difference in capacity effect? (although taking my line of thinking (?) one step further the LDC bikes should therefore have some forward motion when blipping the throttle in neutral).

Gotta stop doing these niteshifts damitt, too much time on my hands.

p.s. From the rumours I here, you Aussies love that lanolin stuff all over yourselves.

i have a 390 and 570.the 390 feels 20 pounds lighter and is a show off in the tight stuff.in the trail the 570 usually hurts me so i leave it for dirt roads and more importantly soon to be coming to the northern hemisphere is ICE RACING. i can hardly wait,the 570 was a monster on the ice last year.

Yep, love that Lanolin:
http://www.lanotec.com.au/testimonials.php :mrgreen:
Especially its HV capability, ie non conductive to 70KV so no static zaps when rubbing down.

As for the things happening when we ride a bike, that's the beauty of bikes, because there is no ONE answer, its all happening, and what and how the rider contributes makes a difference by altering the emphasis.

As for my observations above, they are based on being a rider trainer for the last 18 years with http://www.stayupright.com.au/ and a MA MX and Enduro coach for about 8 years http://www.ma.org.au/index.php?id=754&no_cache=1
I've had plenty of opportunity to analyse and test this stuff, and then demonstrate.

To play with precession, get a bicycle wheel , hold the axle ends while someone spins it, and then use the axle ends as handlebars.

And the one thing I am absolutely certain of is that when there is no sliding involved, outtracking as described above MUST happen. You can test and demonstrate this at walking pace, duck waddling along. Then ride the bike, and do it. When you realise whats going on, you can use it to advantage by forcefully countersteering. If all you do is something else, or combination of, say hips, upper body, head, foot pressure etc, you inherently relax your grip on the bars to allow the countersteer to happen.

Of course I could be wrong :roll:

Now its off to the shed to finish fixing the Berg after its Tubeliss failure and do an oil and filter change.

Steve

The best exercise, if you're game, to assess countersteer is to ride along at say 25-30 kph on a nice smooth flat surface. Take your hands off the bars, keep going straight, now swivel the hips and initiate a turn, you will see the bars countersteer by themselves. Be ready to hold the bars again at any time.

yes there is no answer to this stuff, thats what makes it interesting

FWIW when I removed the counterbalancer and added weight to the crank I noted no difference at all on corner entry which surprised me a lot after being brainwashed with all this "gyroscoptions are bad" stuff

where i did notice a very tiny difference was on corner exit as the revs are higher and the corner is openening up the bike wants to stand up more,

spidey420 said:

i have a 390 and 570.the 390 feels 20 pounds lighter and is a show off in the tight stuff.in the trail the 570 usually hurts me so i leave it for dirt roads and more importantly soon to be coming to the northern hemisphere is ICE RACING. i can hardly wait,the 570 was a monster on the ice last year.

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how about with the engine off, downhill slalom setup with some markers, if its the gyros then the 570 should be almost the same as the 390 whith the engine off.

FWIW Steve in my conditions I think the pivot point for leaning is very close to the contact patch of the tyres with the ground, the sand is so soft they dig in up to 6 inches or so with the anchors on. on tar or slippery gravel i agree the wheels step out as you lay the bike down

Actually, I think the dymanics of turning a bike through a corner are massively complex. If anyone wants to write a 100,000 word research paper on it, I suspect that there will be a Doctorate at the end!

Gyroscopic precession; steering geometry; tyre slip angles, effects of suspension compression; shifting of rider's weight; cross winds; power to rear wheel, what you had for breakfast etc all have an effect.

Let's get back to 'Bergs.

13/52 is the answer.

Greg

Taffy said:

but all you had was two gyroscopic affects with the balancer and then one (bigger) one with the balanced crank. all in all then, a lot of Gyroscopic effect. you'll only notice the difference when there is less of it whizzing round and not which direction it goes in.

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amazing nobodys tried what I said yet FWIW I had the router going the wrong way so for what I said to be true the crank has to be spinning the opposite way to normal, like Rossis first GP1 yamaha or the old maicos

re your quote above Taffy I disagree aboslutely. it makes a difference which direction the mass is spinning, if you have 2 identical flywheels spinning in opposite directions their gyroscopic effect cancels out because a gyros reaction to an input is in a plane at 90 deg to the input, the direction of the reaction depends on the direction the mass is rotating. rotate 2 of them in opposite ways and the reactions cancel out.

or put more simply: the gyroscopic effects come about because the mass is rotating, if it stops rotating there is no gyroscopic effect, two masses rotating in opposite directions cancel out each others gyroscopic forces.

having the counterbalancer where it is on the old engine reduces the gyroscopic effect because its mass rotates in the opposite direction to the crank. having the counterbalancer in there spinning has the same effect as reducing the mass moment of intertia of the crank by the mass moment of intertia of the counterbalancer.

with the bearings and the air Taffy try spinning the same direction as the wheels then the opposite and see how the reaction changes. or put 2 bearings on a shaft side by side one spins one way and the other opposite, now try and move it.. its as easy as if they were no spinning at all.

Im not saying that the gyros don't resist movement im saying the reaction tourque of a gyro being at 90 deg to the input tourque can be useful (if the crank spins the right way )

check this clip

[youtube:ug9o2q9m]http://www.youtube.com/watch?v=LQNunFHH_Cw&feature=related[/youtube:ug9o2q9m]

see how the gyro is happy till the guy turns it then it jumps violently outward

change the direction of rotation of the gyro mass by first winding the string the other way but then do the same thing to it and it jumps inward

there is a pic somewhere on the net and has been posted on this site before of an engine with 1 massive piston, 2 cranks geared together rotating opposite directions and 2 conrods, I'll see if I can find it.

Taffy said:

you lot really didn't guess did ya! :lol: :lol:
I should have guessed my parody would go unnoticed - sheesh! worra bunch! :roll: :roll:
I can say it again at last: does my bum look big in this! :rock: :rock: :rock:
regards
Taffy

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Have you ridden this thing yet Taffy?