Honda Top Case--Does anyone know why it moves?

[ken]

I've seen references to the fact t5hat the Honda Top Case is designed to move on its mount. The directions even require grease to smooth the movement. My question is "Why?" I don't see how making the case move would help with side winds, although that is my best bet. Could it be designed to counteract vibration?

It does not rattle, and I have yet to notice any movement while riding. Does anyone know why it's designed this way?

By the way, for anyone thinking of installing one, I found it very simple task, despite some of the worst instructions I've ever seen. Since I teach technical writing, my students have supplied me with plenty of bad examples; still these were singularly poor.

Also, the instructions call for a 20 mm. hole saw, even though the hole needs to approx. 8.2 mm.

Otherwise, it was a self-evident install, it fits well and looks great.

Ken

 

[Phil Tarman]

This is a "feature" of Honda's engineering. I've been struggling with my CooCase because it never moves. But I've spent all the farkle money I've got and I'll just have to live with it. Oh, well....

 

[ken]

OK, but is it a good feature, bad feature, or an incidental feature? Phil, what is the nature of your "struggle." Do you see an advantage in the movement? Or does it exist just to make me wonder? Inquiring minds need to know.
Ken

 

[JQL]

Note this information is my understanding of various posts by various people on various web sites, forums and my own observations.

As I understand it. Honda had some stability problems at speed (I believe in excess of 80mph - this figure needs to be verified) with the TopBox when it was "Static". In order to raise the speed at which the stability problems occur, the TopBox was made to move slightly. I understand that with the movement this speed has been raised to about 120mph (this figure also needs to be verified).

If you read the bumpf which accompanies the TopBox it says you should not exceed speeds of 130kph (approx 80mph) when it is fitted.

I have noted that, with the TopBox fitted, there can be some handlebar shake at various different speeds. This handlebar shake is virtually eliminated when the TopBox is removed. Does this occur with all makes of TopBox not just the Honda one?

If you want to go faster, take the TopBox off... :evil:

 

[maxweljames]

I'm with Falcon on this one, my E55 causes no problems at high speeds. Only issue I notice is semi-truck buffeting but that's present with or without the top box.

 

[karl]

http://ww1.honda.co.uk/news/motorcycles/20060714.html
the bottom link has gone dead this was in my research pile

 

[ken]

Well, now I know why Honda says it was designed to slide side to side, but I'm still not sure I understand. Obviously, the rider shifts weight to the inside of a corner, so having the case do the same makes a certain amount of sense. However, I agree with Rick that the minimal weight of the properly loaded OEM top box would seem to make very little difference, whether it is static or mobile. Intuitively, the movement could be distracting, just as a "helpful" passenger's movement is. However, I am unable to feel any effect, either positive or negative, so far. It does look good though.

As for the instability above 80 mph, I suspect this has more to do with potential aerodynamic differences and Honda's desire to absolve themselves of liability. Fortunately, there are few places to legally exceed 80 mph. Since I am now a law-abiding citizen, this is a non-issue for me.

Thanks to everyone for their help.


Ken

 

[Phil Tarman]

Phil, what is the nature of your "struggle." Do you see an advantage in the movement? Or does it exist just to make me wonder? Inquiring minds need to know.
Ken

Ken, I was being sarcastic. (My wife tells me that is not my most attractive "feature," BTW). Honda puts out a line that it helps with vehicle dynamics. I'm very dubious about that. My CooCase doesn't move; my Givi never moved on either of my Concours; and all three bikes worked (and work) just fine at speed in very high winds. I haven't been able to think of any good reason why vehicle stability would be enhanced by a moving part. Particularly a moving part that may be loaded. Even if the initial movement might help, reaching the limit of allowed travel would seem to my simple mind to impart a "jolt" to the bike. You can't stop something without an energy transfer. Might as well allow the wind gust to impart that transfer as having a moving case slamming to a stop do it a millisecond later.

I don't know if it's good or bad. It just seems dumb.

I do know that I've had more than the placarded weight limit in every pannier and top box I've ever owned (that's four panniers for Concours, two panniers for NTs...with two different lid sizes, it might be four NT panniers, and a Givi topbox on both Connies and the CooCase on the NT). I've had the NT to 100+ mph both with and without the topbox and, honestly, could not tell any difference in vehicle stabilty.

The only time I've felt any untoward handlebar movement is a very slight "hunting" sensation at 30mph. If I take my hands off the bars at that speed, nothing happens. If I leave them on the bars, I can feel a low-frequency oscillation. I'll have Dana check the headset bearings when he does the 24K service.

 

[Warren]

Note this information is my understanding of various posts by various people on various web sites, forums and my own observations.

As I understand it. Honda had some stability problems at speed (I believe in excess of 80mph - this figure needs to be verified) with the TopBox when it was "Static". In order to raise the speed at which the stability problems occur, the TopBox was made to move slightly. I understand that with the movement this speed has been raised to about 120mph (this figure also needs to be verified).

If you read the bumpf which accompanies the TopBox it says you should not exceed speeds of 130kph (approx 80mph) when it is fitted.

I have noted that, with the TopBox fitted, there can be some handlebar shake at various different speeds. This handlebar shake is virtually eliminated when the TopBox is removed. Does this occur with all makes of TopBox not just the Honda one?

If you want to go faster, take the TopBox off... :evil:

When MCN tested the NT they reported its top speed as 118mph and then noted that was with the top box installed. No mention of any stability issues.

 

[silverdevil]

I had a Kaw Voyager in the past and my dealer and I fixed our Voyagers so that the top box could move forward and back to give the passenger more room and could move it forward when no passenger
I have never heard of a top box that would move side to side, to me that would be dangerous when taking curves fast and tight.

 

[Warren]

For what its worth I mentioned in a previous post that in reading a review of the new Triumph sport tourer that they have their built in saddle bags set up to move side to side for similar reasons as Honda has expresssed for the top box. Not sure if they are drinking the same coolaid as Honda but maybe these guys know more about this subject than we are giving them credit for.