ahend
1 mW
With my brushless front hub motor locked into a constant speed, be it fast or slow, the front wheel will start an oscillation when both hands are removed from the handle bar. The torque creating this oscillation cannot be felt in the bar at any time during normal riding conditions. This happens almost immediately after I let go, and it quickly gets out of control with the wheel violently sweeping left and right equally.
I first noticed this when I sat upright for a breather (I pedal hard a good deal of the time) and placed my hands on my hips. I’m sure someone got a good laugh watching me pull in the reins, trying to recover from what would have been a nasty toss.
Though I do not consider this a problem that needs to be rectified, I am curious as to what may be the cause. Considering the front end of a bicycle was never designed to propel the frame and rider, could the frame and or fork geometry somehow be responsible? I should think that the fork rake would tend to make the system more stable when a force is applied at the dropouts. Another thing I’ve considered are my torque arms. Since my suspension fork (perhaps another contributor) is aluminum, I have made some serious torque arms (one on each side) with anti spreading measures, that lever force a good 5 inches up. Could they be batting reaction forces back and forth? Perhaps this is an inherent condition of a hub motor as tangent forces pulsate off the circumference of winding diameter to complete a cycle.
Any thoughts? Can anyone duplicate this phenomenon?
I first noticed this when I sat upright for a breather (I pedal hard a good deal of the time) and placed my hands on my hips. I’m sure someone got a good laugh watching me pull in the reins, trying to recover from what would have been a nasty toss.
Though I do not consider this a problem that needs to be rectified, I am curious as to what may be the cause. Considering the front end of a bicycle was never designed to propel the frame and rider, could the frame and or fork geometry somehow be responsible? I should think that the fork rake would tend to make the system more stable when a force is applied at the dropouts. Another thing I’ve considered are my torque arms. Since my suspension fork (perhaps another contributor) is aluminum, I have made some serious torque arms (one on each side) with anti spreading measures, that lever force a good 5 inches up. Could they be batting reaction forces back and forth? Perhaps this is an inherent condition of a hub motor as tangent forces pulsate off the circumference of winding diameter to complete a cycle.
Any thoughts? Can anyone duplicate this phenomenon?