This is a good physics exercise.
Let's look again at gggGary's snapshot of the bike's and truck's situation just moments before impact.
Now, establish some data factoids.
(Sorry metric guys, you'll have to fend for yourselves)
1 G = 32 feet per second per second = Acceleration due to gravity
1 mph = 1.467 feet per second
Now comes the fuzzy analysis.
Best guess estimates from examining the video (numbingly over and over and over):
The motorcycle speed, approaching impact = 44 mph (65 fps)
Viewing the video, with stopwatch, trying to account for the slight fisheye imaging, was able to guesstimate the 65 foot travel over one second.
This gave the estimate of the distance to impact = 40 feet
Which means a time to impact = 0.6 seconds
The motorcycle is continuing its turn, after exiting the curve, and appears to have a lean angle of 20°.
The tangent of 20° = 0.36
Which gives the centripetal acceleration from that existing lean angle = 0.36 G
This pic shows the current path to impact in red.
I'd like to be at least 4 feet to the right of that, to clear handlebars and such from the truck.
To do that, means following the track in green.
View attachment 57480
So, let's calculate the amount of acceleration to get that additional distance to clear truck = 4 feet
where: s = distance, a = acceleration, t = time
s = 1/2 a * t * t <--(standard formula when acceleration is constant)
a = 2s / (t*t) <--(transformed to solve for 'a')
a = 2 * 4ft / (0.6sec * 0.6sec) <--(plug in our values)
8 / 0.36 = 22.2 fps/s = 0.69 G <--(simplify and solve)
Acceleration needed to travel 4 feet in 0.6 seconds = 0.69 G
With the bike's existing centripetal acceleration at 0.36G, then adding the additional acceleration of 0.69G, we get:
Total acceleration needed = 0.36G + 0.69G = 1.05G
However, the typical G limits for street compound tires = 0.85G
Which means that there's not enough traction to achieve the escape route.
It gets worse if you account for the time losses due to:
- Application of corrective countersteer
- Time required for the motorcycle to achieve the new lean angle
In summary, my feeling is that, for this particular snapshot, an impact is inevitable.
Which explains why I grit my teeth everytime I see that pic...