rear hard case for 05 that doesn't cause front end wobble

[jezet]

New to the FJR as I just got it yesterday. I heard that the rear hard case causes a wobble in the front end is there anything you can do about this ? Thanks I can't wait to ride this awesome machine this year (I'm upgrading from a 06 z750 that I have toured on about 16000 in two year summer months only )! And I'm really stoked about this site and looking forward to talking to you all and hopefully riding with some of you!!!

 

[johnny80s]

Welcome to the forum!

 

[MartyA]

I never noticed any wobble. I do get head shake, every time I pass another disadvantaged soul on a second class bike I just shake my head and wonder.....

 

[profireguy]

Welcome, and I think you got some bad info. I think you would have a harder time finding one that did make it shake. I don't recall anyone complaining about a specific brand of case, but I don't see every post, either.

 

[03silverbullet]

A rear hard case won't make it wobble but it may make the bike less stable in windy conditions.

 

[Phugedaboudet]

had the Yamaha topcase with backrest pad on for well over 7K miles, only "issues" I've had is in severe crosswinds, passing thru the "bow shock" of a big rig at speed, or dealing with grooved pavement. Same sorta stuff I had issues around without the topbox.

Tho it is a good idea to have something in the box if you're going to be riding at speed. Otherwise the box tends to shake a little if there's no weight to hold it steady.

 

[NightShine]

This topic had come up a couple of years ago. My understanding of the issue was that when riding an FJR with a top case, but no pillon, at "aggressive cruising" (aka triple digit) speeds, some riders experienced a shimmy / wobble / instability. They attributed it possibly to an aerodynamic condition caused by the void between the rider and the top case at those speeds, as the condition disappeared after replacing the void with body or baggage.

I don't have a top case, just passing along my recollection of the matter...

 

[myzen]

On my trip home from Houston, I was on a back road riding about 75mph, as I came upon a slow moving truck, I twisted the wick and got it up to 107 mph (looked at the GPS) as I was passing. When I did so, I did feel the bike go into a wobble. It went away as I rolled off the throttle. It was a little unnerving to say the least.

At the time, I was running a GIVI 46 top case, Corbin Smuggler, and the side bags.

 

[whataboutbob]

On my trip home from Houston, I was on a back road riding about 75mph, as I came upon a slow moving truck, I twisted the wick and got it up to 107 mph (looked at the GPS) as I was passing. When I did so, I did feel the bike go into a wobble. It went away as I rolled off the throttle. It was a little unnerving to say the least.
At the time, I was running a GIVI 46 top case, Corbin Smuggler, and the side bags.

I have a factory top case and noticed the wobble/unstable feel at speeds above 80mph on the super slab.took if off and ran again without box and feeling went away.oddly it seems to happen only on the interstates not the state roads or secondary roads.perhaps it has to do with too much cross wind on a wide open area.Bob

 

[madmike2]

This topic had come up a couple of years ago. My understanding of the issue was that when riding an FJR with a top case, but no pillon, at "aggressive cruising" (aka triple digit) speeds, some riders experienced a shimmy / wobble / instability. They attributed it possibly to an aerodynamic condition caused by the void between the rider and the top case at those speeds, as the condition disappeared after replacing the void with body or baggage.
I don't have a top case, just passing along my recollection of the matter...

I believe it is also an extension of the Yamaha warning to not ride with the top case and panniers attached. IOW, legalize to free them from responsibility.

The wobble is not a "tank slapper" type (AFAIK) but more a high speed weave. When I used to run my Givi 42L at high speeds I got worse gas mileage. I believe that was caused by the vortices between rider and top case because those riding 2-up didn't suffer the same mileage loss. That would also explain the forces at work that could cause an issue with stability.

That being said, while riding on a private test track at speeds over 110 mph, my FJR was never unstable. I would think that loading or unloading the suspension on a road that rises and falls or sudden throttle changes might exacerbate the problem, as would any crosswind or headwind.

When traveling on extended trips I would put a Cortex tail bag between me and the top case (loaded with my tool kit, first aid kit, cleaning rags and sprays, etc.) and that eliminated the mileage loss and I never had any stability issues.

I think you should ride it and try it before assuming it is a widespread phenomenon. IF you have a problem, you now have a couple of suggestions as to "how" to ameliorate any issue.

 

[Bustanut joker]

Damnit! Mike went and made sense.. An ruined the whole thread.

:jester:

 

[myzen]

This topic had come up a couple of years ago. My understanding of the issue was that when riding an FJR with a top case, but no pillon, at "aggressive cruising" (aka triple digit) speeds, some riders experienced a shimmy / wobble / instability. They attributed it possibly to an aerodynamic condition caused by the void between the rider and the top case at those speeds, as the condition disappeared after replacing the void with body or baggage.
I don't have a top case, just passing along my recollection of the matter...

I believe it is also an extension of the Yamaha warning to not ride with the top case and panniers attached. IOW, legalize to free them from responsibility.

The wobble is not a "tank slapper" type (AFAIK) but more a high speed weave. When I used to run my Givi 42L at high speeds I got worse gas mileage. I believe that was caused by the vortices between rider and top case because those riding 2-up didn't suffer the same mileage loss. That would also explain the forces at work that could cause an issue with stability.

That being said, while riding on a private test track at speeds over 110 mph, my FJR was never unstable. I would think that loading or unloading the suspension on a road that rises and falls or sudden throttle changes might exacerbate the problem, as would any crosswind or headwind.

When traveling on extended trips I would put a Cortex tail bag between me and the top case (loaded with my tool kit, first aid kit, cleaning rags and sprays, etc.) and that eliminated the mileage loss and I never had any stability issues.

I think you should ride it and try it before assuming it is a widespread phenomenon. IF you have a problem, you now have a couple of suggestions as to "how" to ameliorate any issue.

I agree, I would describe it as a weave, more than a wobble.

 

[zzzzip]

I had an '04 with factory hard case and never had any problems (other than in the above mentioned situations-- and wasn't really a problem) for the 18,000 miles I had it. I probably only put 4,000-5,000 with the case on.

B)

 

[HaulinAshe]

This topic had come up a couple of years ago. My understanding of the issue was that when riding an FJR with a top case, but no pillon, at "aggressive cruising" (aka triple digit) speeds, some riders experienced a shimmy / wobble / instability. They attributed it possibly to an aerodynamic condition caused by the void between the rider and the top case at those speeds, as the condition disappeared after replacing the void with body or baggage.
I don't have a top case, just passing along my recollection of the matter...

You are exactly right!

I am both the former owner of an '05 and present owner of an '07, both with Yami top cases. There's nothing unstable about it until you reach triple digits without a passenger in place. (on a closed track of course!)

 

[Potential]

I usually ride at 100 mph indicated on the interstate, always solo, always with a Givi V46 topcase and no side bags, usually with the topcase being almost empty, and usually with the windshield raised fully up. I never noticed any instability. However I do grasp the grips very firmly.

Oh yeah, this is a 2008, so it's a Gen II. Are the Gen Is more prone to instability?

 

[Toecutter]

That being said, while riding on a private test track at speeds over 110 mph, my FJR was never unstable.

I ride on another part of that same private test track with my Givi V46, and I get similar results. The "weave" is actually kinda cool, to me, and only seems to happen when the case is heavily loaded. I once had an occasion to ride the track with another rider that had a Yamaha topbox on. He had to shut it down due to instability issues.

 

[windchaser1942]

I'm sure not a so called "scientist" on this issue but I have experienced it myself. First time I thought the rear tire was going flat. Others have given answeres based upon their personal experience and no doubt what they experienced was real for them. Apparently the size of ones body and "position" on the bike, amount of quartering crosswinds, the load in both the top and side cases and whether or not the "gap" between rider and the case is full or open and the position of the windshield can affect this phenomenon. For me, if I need to hit the interstate on a windy day and I don't need the top case storage I take it off and leave the windscreen in a lower position. If I need it then I make it point to fill the space between me and the case. You will just need to experiment with it until you find a decent alternative. I don't believe there is a "magic" or one time fix for the issue. However, just knowing that it can happen makes it a little easier to deal with.

 

[KSFJR]

Had a Givi 46 on my 05 and couldn't even tell it was back there. Was doing 130 one time with it on when Smitty141 flew past me on the GSX1000 he owned at that time and the box was never an issue. Did come across I-80 through Wyoming and Nebraska one night with winds out of the South about 45 - 50 mph. Now that was obnoxious but I can't totally blame the box.

Chester