Interesting video. What about the torque reaction from the torque going through the rear wheel to the road. This would also be trying to lift the front of the bike so shouldn't it be considered too?
The torque at the rear wheel is taken into account in this problem. Since we are tasked to solve for acceleration, we don’t frame the problem in terms of rear wheel torque. The acceleration we solve for in this problem is the effect of torque on the rear wheel. At the end of the video we solve for the frictional force between the road and the tire. If we knew the diameter of the wheel, we could solve for the resultant rear wheel torque needed to lift the front tire off the ground. Also, note that this is a static problem, we are not considering dynamic effects (the rider shifting weight, effects of “popping the clutch, etc.) It is a simplified analysis, in reality, by shifting your weight and using the clutch advantageously it would require much less acceleration to lift the front wheel off the ground. Thanks for taking the time to watch the video.
