- #1
motolectric
- 4
- 0
Hi,
I have a few energy questions and I'm hoping they are welcomed at this forum.
I'm dealing with the idea of reducing "unsprung weight" on motorcycles.
This is the weight of items below the suspension, i.e. the wheel, tire, brake discs etc.
My first foray into this was back in the Usenet days when I asked on a Usenet forum why reducing 1 pound from my tire (by going to a smaller cross section tire - and 25 inches diameter to 24) made such a huge difference to how my motorcycle handled. The guy who answered said that since the weight difference was located 12 inches from the axle that it was the equivalent of a 64 pound reduction in weight (I had supplied the data in my question that the only difference between the tires, was 1 pound in weight which seemed [based on the appearance and measurements] to be all at the circumference of the tire).
His figure coincided with my seat of the pants conclusion, i.e. it was very large.
I state the above in case anyone here can chime in that it is off or add anything to it.
My question now is;
I have a wheel/tire/fender/axle that is going along at 70 MPH and it hits a bump that is 3 inches high.
I have another wheel/tire/fender/axle that weighs 1 pound less and it is going at 70 MPH and it hits the same bump.
How much less energy is needed to lift the 2nd combination vs. the 1st?
On motorcycles reducing unsprung weight makes very large differences in the handling but the changes are on the order of 8 ounces, 16 ounces etc.
I'm curious as to how much energy savings there are and why.
Also is there a curve to the energy required to lift the 2 weights (I would think there is based on the speed).
If the calculations need real world base figures I would think 40 pounds and 41 pounds would be close to what is on a motorcycle.
But would it be different if the real world weights were 1 pound and 2 pounds?
Thanks for any tips/advice/feedback.
M./
I have a few energy questions and I'm hoping they are welcomed at this forum.
I'm dealing with the idea of reducing "unsprung weight" on motorcycles.
This is the weight of items below the suspension, i.e. the wheel, tire, brake discs etc.
My first foray into this was back in the Usenet days when I asked on a Usenet forum why reducing 1 pound from my tire (by going to a smaller cross section tire - and 25 inches diameter to 24) made such a huge difference to how my motorcycle handled. The guy who answered said that since the weight difference was located 12 inches from the axle that it was the equivalent of a 64 pound reduction in weight (I had supplied the data in my question that the only difference between the tires, was 1 pound in weight which seemed [based on the appearance and measurements] to be all at the circumference of the tire).
His figure coincided with my seat of the pants conclusion, i.e. it was very large.
I state the above in case anyone here can chime in that it is off or add anything to it.
My question now is;
I have a wheel/tire/fender/axle that is going along at 70 MPH and it hits a bump that is 3 inches high.
I have another wheel/tire/fender/axle that weighs 1 pound less and it is going at 70 MPH and it hits the same bump.
How much less energy is needed to lift the 2nd combination vs. the 1st?
On motorcycles reducing unsprung weight makes very large differences in the handling but the changes are on the order of 8 ounces, 16 ounces etc.
I'm curious as to how much energy savings there are and why.
Also is there a curve to the energy required to lift the 2 weights (I would think there is based on the speed).
If the calculations need real world base figures I would think 40 pounds and 41 pounds would be close to what is on a motorcycle.
But would it be different if the real world weights were 1 pound and 2 pounds?
Thanks for any tips/advice/feedback.
M./