Luggage Oscillation, ton up.

[vespadaddy]

After being ill for 3 weeks, and waiting for rain to wash away the salt, and waiting for a nice day, I took my maiden voyage on the FJ-09 today. (I hadn't even started the bike, and bought it in Feb).
 
My bike is set up with the factory hard cases, and the Yamaha 50 litre topcase. All bags were attached for the ride.
 
First, the seating position is reminiscent of my old KLR650.  It feels like a rolling couch, compared to the sportbikes I have owned previously.  Except this rolling couch has a lot more power.
 
After running the bike up through the RPMs, up and down, I opened the throttle in 6th and waited.  Each time, same result:  smooth power, rapid acceleration, and, at 100 mph (closed course, etc etc etc), the bike began to oscillate.  As soon as I rolled off and speeds drop into the 90's, it smoothed out.  The bags were all empty.  I repeated this several times, with the same results.
 
I'm bringing my bike in for the warranty shift shaft repair tomorrow.  I'll pull the bags before I ride it to the dealer, and will report back after the service.  I'm curious if it will oscillate with no luggage.

[wessie]

No, it will not oscillate with no luggage. I've had it up to 134mph with a top box fitted (and probably 120mph with no luggage). No oscillation and still accelerating but I was going blind due to the airflow through my helmet, pushing my sunglasses into my eye sockets. Plus someone had installed a motorway intersection on my private road which dented my confidence.
 
If you read the manual, Yamaha state that the bike should not be ridden with 3 cases fitted, whether in the US or Europe. I guess the US speed limiter has something to do with what Yamaha discovered in a wind tunnel and their wariness of US lawyers.
 
Perhaps try your experiment with 10kg in each box? The added mass may settle the bike.
 
My Givi rails & Kappa boxes should be with me later this week so some time this month I will conduct a similar experiment.

[vespadaddy]

If you read the manual, Yamaha state that the bike should not be ridden with 3 cases fitted, whether in the US or Europe. I guess the US speed limiter has something to do with what Yamaha discovered in a wind tunnel and their wariness of US lawyers. 
Perhaps try your experiment with 10kg in each box? The added mass may settle the bike.
 
My Givi rails & Kappa boxes should be with me later this week so some time this month I will conduct a similar experiment.

IIRC, Yamaha says not to use 3 cases due to risk of overloading the bike.  I ignore this, as I keep my top box nearly empty, and plan to use it to hold my fedora when I'm on the bike, and my helmet when I'm not, so the weight issue is not applicable. 
 

[papifun]

I'm curious too.. But with only side hard bags..

[vespadaddy]

I rode the bike again today to have the shift shaft repairs made, and on this trip, I removed the side cases, but left the 50 L Yamaha trunk on the bike. 106 mph, and no oscillation whatsoever.
 
I wonder if the oscillation is worse with the wider FJR bags?
 
Anyway, I'll probably only use the side cases when I'm on a trip with the Mrs as pillion anyway, so no need to break the ton then for me.
 
I would actually expect the oscillation to be more severe, or to begin at a lower speed with weight in the side cases. My theory is that the front sail area of the bags is creating turbulence AND sufficient drag on the back of the bike to lighten the front end enough to initiate the oscillation. *IF* that's true, I would expect the weight of a passenger and loaded bags would exacerbate the problem.