Should the top box mount have play in it.

[Mark Millard]

Hi, just took my Honda top box off for the first time, there appears to be a slight amount of play between the large plastic mounting bracket on top and the metal one underneath, it slides around about a quarter of an inch, I tried tightening up the the four 10 mm bolts underneath but they just turn and the upper heads of these bolts are covered by a plastic sealing cap, perhaps this slight movement is required as it is only side to side and not up and down, does anybody know if this is correct or if their top box is the same ? Thanks Mark.

 

[elizilla]

It's supposed to do it. Honda claims it helps with the handling problems introduced by having that weight so high up. I reserve judgement, but I do know it's designed that way and supposed to do it.

 

[seagrass]

Definitely supposed to be that way.

As Katherine said Honda designed it this way and it is designed to help handling in cross wind situations.

There is a Honda video about how it works, I can tell you where to get a copy of the video if you send me your email address.

 

[Phil Tarman]

Dan's Triumph Trophy has moving panniers based on the same theory. I'm dubious about the real effectiveness of that "feature." Seems to me that when the top box or the panniers on the Triumph gets to the end of its movement range it is likely to put more movement into the bike than it kept out by moving in the first place.

I'm not an engineer and I didn't spend last night in a Holiday Inn Express, but intuitively any real benefit from this design feature seems minimal at best.

 

[Mark Millard]

Thanks all for that info, just put my mind to rest as I didn't want the top box falling off. Thanks Mark.

 

[Warren]

When one looks at the Honda top box design its clear that it is designed to move sideways. No sloppy engineering to it. Its actually quite precise.

 

[RedNigel]

I don't believe that for a minute. Having 1/4 inch right-left movement is nothing but sloppy engineering. A slight weight shift at an inappropriate time could cause trouble in a turn. None of my past luggage or topcases have had any movement. Balderdash!

The left right movement is engineered into the rack
There is an aero/stability component as a reason for the sliding motion

Look it up

 

[Phil Tarman]

I'm with Sam on this one. It may have been intentional...that doesn't mean it's a good idea or that it's got any effectiveness. Sounds like some engineer had a "bright" idea that nobody really thought through. I'd bet small amounts of money that there were never any controlled tests of the effectiveness of this innovation... either by Honda or Triumph.

 

[RedLdr1]

I'd bet small amounts of money that there were never any controlled tests of the effectiveness of this innovation... either by Honda or Triumph.

Yep, the whole concept is a bit "interesting".... Hmm, having some "slop" in the trunk luggage mounting, allowing a weight that is high mounted and at the rear overhang of a motorcycle to shift from side to side, will improve stability? Really? Even if you are riding one up that area is pretty well shielded from the air flow the trunk mounting is supposed to react to... ride two up and it is really shielded.... Good marketing hype but I want to see some real proof, wind tunnel videos for example, that it works, at a level a rider could notice, before I'll believe it...

 

[elizilla]

This is a conversation I have all the time at work. "Working as designed" doesn't mean the design is good. It just means that the finger of blame must be pointed at the designers rather than at the guys who built it.

From the end user's point of view it may look the same, but it's not. If what was built met the spec, then it's not the builder's responsibility and they won't fix it. We have to take it up with the people who wrote the spec. Totally different path to resolution.

 

[tommyr]

My children on the back moving around do nothing to improve the handling. I'm doubtful luggage moving around would either. I've got my mount screwed tight so it doesn't.

 

[RedLdr1]

My children on the back moving around do nothing to improve the handling. I'm doubtful luggage moving around would either. I've got my mount screwed tight so it doesn't.

I'm not even going to ask how you fixed the children moving!....

 

[dnktng]

This Honda link has Honda's reasoning.

 

[Phil Tarman]

Well, that's a laugh! My model passenger doesn't move with the wind. Honda tells you in that link to connect to the video that shows how the floating top box works, but the video link doesn't go anywhere.

 

[RedNigel]

You guys just keep hatin' on our topboxes
Very productive

 

[Phil Tarman]

I'm hating your top box. I doubt if it moves enough to feel it. They're fine looking and fine working top boxes. I just don't think that topboxes need to move.

Don't take it personally.

 

[RedNigel]

I'm hating your top box. I doubt if it moves enough to feel it. They're fine looking and fine working top boxes. I just don't think that topboxes need to move.

Don't take it personally.

I did for a minute but I'm OK now....Work situation has me a in a very black place right now

Regarding the box: If it moves at all, it is imperceptible. From the moment I rode it out of the shop where I had it installed, I've never given it a second thought.
Plus, as the nylon washers it slides on wear out, movement is more and more difficult, so it probaly only moves IF its heavily loaded and IF you are in tight twisties riding hard, and even then you would be unaware of it.
Trust me; I'm 30,000 miles in and the box and its potential lateral play has NEVER been an issue

P.S. Maybe the fact that I am totally unaware of any movement proves that the engineering is sound

 

[Phil Tarman]

I'm 30,000 miles in and the box and its potential lateral play has NEVER been an issue

Didn't figure it would ever be an issue.

 

[RedNigel]

Didn't figure it would ever be an issue.

My understanding of the rationale behind the play was to eliminate an almost imperceptible handlebar shimmy at speeds above 80MPH when the box was static
The fine print for the box suggests you dont ride above 80 with the topbox on. Of course, we know that speeds above 80 arent a problem either (ahem)
There must have been some kind of high speed aero issue before the lateral give and take was designed into the box setup

 

[Phil Tarman]

I've never had a Honda topbox, but I can guarantee after riding in the winds of Colorado, Wyoming, Kansas, Nebraska, Newfoundland, and a few other places and after riding at speeds well above 80mph in some of those places, I've sure never felt a trace of aerodynamicly-induced handlebar shimmy with either a Givi Maxia or a CooCase.

I'm still arguing that this was "fix" that some engineer decided was important to deal with an issue that probably wasn't caused by the topbox's rigid mounting.