What cause all the handlebar movement?

[faffi]

 

The handlebars move a lot and quite violently. Not unusual per se, but quite strange for me to see it also in virtually straight line riding. The few times I've filmed myself, that doesn't happen to me, so I guess it's down to me being slow, but it would be interesting to hear why all the movement in the front.

 

[Jaybird180]

Trail

[Hotfoot]

If you look at the rider's body movement, you can see that it's not a smooth ride.

I'm thinking a combination of bumpy road, wind buffeting (the riders are pretty close together and the speeds are high, getting up into the 150mph range), and a much stiffer suspension and tire carcass than you'd see oh a street bike, plus a bike setup that is much twitchier than a cruising bike so it reacts more. 

Also the hard acceleration and braking may cause the rider to add some unwanted bar input, you can see from the rear view how much the riders are moving around.

On my racebike at one particular track there is a high speed section (150-170mph range) close to a wall and the wind buffeting from the wall or any nearby rider is very noticeable, it wobbles your head around and makes the bike move around, you can feel the bars move, even though you are going straight.

Have you felt your handlebars move in wind or when passing a large vehicle?

[faffi]

Thank you for sharing your insight, Hotfoot. I've never thought about the bars moving when being hit by gusts, but since the bike is often blow off course that seems quite likely.

[tomw]

The title is slippy drying street circuit, at the pace they are riding, I assume they are fighting traction the whole way. What does the front do when the rear loses traction (and the rider doesn't try to fight it?) Would slip and grip events with proper light weighting the handgrips make the handlebars seem to "jolt" from the reference frame of the motorcycle? When they leave the ground and land on the front after the forks compress all the way, what should handlebars do at that point to maintain overall motorcycle stability. Is the motorcycle actually stable or unstable here?