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Originally Posted by Just Riding Along
We're going to presume a moving vehicle, so it has momentum, and the wheels are turning. Since it would be impossible to create a massless wheel and we're moving (velocity) we will never reach the theoretical wheel that is “too light”. Every particle in the wheel has angular momentum. When you try to change that momentum there is a reaction. This is the talk about gyroscopic reaction and precession start rearing up.
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Just riding along I'm only quoting you as an example,I needed your above statement...
About three pages ago sombody made the comment that it's not the weight of the wheel it's the % of the wheel weight to the total weight of the bike.
So what would happen if we put a set of BST carbons on a bike that weighed in at 1000 lbs?(besides crushing the poor wheels).
It would still turn,I'm sure,but be very quick to roll off center.
I also posted above about riding in a very high cross wind and to maintain striaght forward motoin I had to steer,ie turn,the wheel into the wind and lean.Without the force of the wind this will result in a very sudden change in roll position.It would stand the bike up and roll it to the other extreme.
Whether we realize it or not every one of use who rides countersteers to start the roll and lean then aplies opposite counter steering to hold that angle then countersteers to straiten up and continue to the next turn .The veriable is in how fast we do this.Useing Codes No BS bike as an example without steering the bike with our hands the bike still turns because while the rider moves his body about trying to lean it the fork rocks ever so slightly causing a counter steer,this force could even be appied from the road through the tire,but it happens the bike finely turns.The problem in riding the NoBS bike was not starting the turn but coming out of it,riders who dared had to have almost stand up to get the required leverage to pull the bike up and over the high side to the next turn.
So now we put or new BST's on that old American Eagle,or even a Boss Hoss not 1000lbs but in the 800's I'm sure.What will happen?
The wheels weigh in at about 12-18lbs for the pair(somebody may want real numbers with tires and brakes,but I'm going to go with 20lbs total up front and 30lbs out back) so 50 lbs total of wheels is about 6% of the bikes total weight thats low. The bike will turn but the challenge would be in catching the roll rate before the bike ,floor board,frame,valve cover hits the road.If you did picking it up,with counter steering would be easy except you would need to catch it at the top to keep from going too far then correct again until you steered it back straight.
A light wheel allows the roll to be started easier so one may feel the bike is unstable,the truth is the stability is the same,the built in geometry of the bike takes care of that,it's the required force that starts the roll that changes,so the bike feels twitchy,put that iron wheel back on and the force would go way up but with enough force it would still turn,like a truck.
Gyro force has nothing to do with turning except for how much force is required to start the lean and stop it.
Flame suit on!