Back end getting squirrely when shifting on hard acceleration

[WhiteStripe]

Wondering if this is a common flaw of a less experienced rider?

When i have the opportunity to accelerate quickly, say merging onto a highway from 35 mph to 90 mph i have noticed that some of my shifts create a bit of a feeling of instability in the back end.  almost like the bike tire wobbles for a split second.

Wondering if i am changing my position on bike, or not shifting correctly creating some drag on back wheel?

Figured i woudl throw it out there to see if this is a common mistake from a newer rider.

[corey]

New tires?
I notice with new tires that the triangular profile require a little more care on my part to keep my ass steady and not flop around so much on the bike.

[hypurone]

To rule out the rider as the cause. Focus on making your quick shifts with as little input to the bars as possible. Slight inputs there "translate' to the whole/rear of the bike. Hold the grips like a couple of Twinkies! Your movements can be fast but they MUST be smooth and gentle... 

Or it could be you are putting down the max power for the tire and/or road conditions... YMMV

[Dietrich]

At my first track day they make first timers stay in the beginner group and also attend "class" in between sessions.  After the second session we all went back to the little trailer class and sat down for some Q&A.  Some guy on a rented 1000cc japanese sport bike, in rented leathers, raised his hand: "It seems like the back end is sliding around when I accelerate out of corners?"  Of course it was!    New rider on a liter bike, ham fisted, and cracking the throttle equals wheels spin, and this guy had no idea....it was scary being on track with him and I stayed as far away as possible!

I'm not saying you are this way at all....just that you might be getting some wheel spin (or skid) if the revs aren't matched for road speed when you let out the clutch.  Also agree with the previous post about unintentional control inputs.  Practice accelerating smooth and relaxed...and fast as possible... 

When in doubt, throttle out.

[ducpainter]

To rule out the rider as the cause. Focus on making your quick shifts with as little input to the bars as possible. Slight inputs there "translate' to the whole/rear of the bike. Hold the grips like a couple of Twinkies! Your movements can be fast but they MUST be smooth and gentle... 

Or it could be you are putting down the max power for the tire and/or road conditions... YMMV

+1

I suspect you're feeling input to the handle bars.

[He Man]

are you shifting with or without your clutch?

[WhiteStripe]

Thanks guys - this is defintlly a rider error not bike. 

I do generally use the cluctch, but have been working at getting smoother and using less clutch.

I agree that it is probably handle bar input - i think i am getting a little 'overexcited' and moving around too much - working on keeping my body quieter on the bike.

Thanks for the thoughts!

[Latinbalar]

Also motorcycles tend to move around on you, if you ask anybody who does track days they will tell you it move alot underneath you.  During spirited rides or hard acceleration put most of your weight on your feet and let the bike do what it has to do under you.  It has a tendency to keep you going in the right direction.

[swampduc]

I agree that it is probably handle bar input - i think i am getting a little 'overexcited' and moving around too much - working on keeping my body quieter on the bike.

Keeping your body quieter will happen if you focus on relaxing. It's especially important to relax your grip on the bars. The death grip that lots of riders have early on could be causing a lot of your trouble.