Topic: Please identify this piece of plastic for me...

[TravisB]

I opened my seat on my 1975 CB550F SS and found this little plastic piece hanging around loose on top of my rear fender (the portion covered by the seat).  I glanced around, but couldn't figure out where it came from or if it's at all important.  Check out the pictures and let me know what this is.  Thanks!

[DustyRags]

Looks like that bit of plastic that hangs off the underside of the seat. It's where you're supposed to stash your registration papers.

[TravisB]

It's not this piece, if that's what you're referring to, DustyRags.

http://i.ebayimg.com/t/honda-cb750-cb550-cb500-under-seat-storage-door-05544-/00/s/MTIwMFgxNjAw/$T2eC16NHJHEE9ny2qTT2BQKUo05JNQ~~60_35.JPG

[DustyRags]

Huh, yeah, you're right. Never mind.

[WarwickE36]

Tool kit storage?  That's a total guess though

[Hannibal Smith]

Beta-Max tape?

[LesterPiglet]

Is it some sort of dirt shield? It looks like it attaches to the same place as the rear plastic fender.

[mono]

Q: was this the 1st time you've ever opened the seat up?  Maybe it's just a random piece of plastic that the PO had in there.

I don't think it's off your bike.  My best guess is that it's a chunk of plastic to put under the license plate to keep it from rattling.  Total shot in the dark, but it would make sense for the PO to remove it (took off the plates) while selling the bike and stash it under the seat (still useful to the bike).

Professor Plum in the Conservatory with the Candlestick.

[TwoTired]

The F model moved the tool pouch storage compartment from a tray above the filter to the rear portion of the seat.

What you have there is part of the cover that holds the tool kit in place in the seat pan.  They used a thinned section of the plastic as a hinge and yours has severed there.  At the back of the seat pan you'll find two "hooks" that engage the slots.
The other (missing?) part of that plastic extends toward the front and is secured by two wing nuts.  It alone is not enough to keep the tool kit in place on rough roads.

I have used duct tape (or even better 100MPH tape) to make a new hinge for the two pieces, which works for the short term.  Better would probably using small hinges found in the hardware store and fastening the two parts together.

Cheers,

[mono]

^  damn... i was Col. Mustard after all....

[750resurrection]

The F model moved the tool pouch storage compartment from a tray above the filter to the rear portion of the seat.

What you have there is part of the cover that holds the tool kit in place in the seat pan.  They used a thinned section of the plastic as a hinge and yours has severed there.  At the back of the seat pan you'll find two "hooks" that engage the slots.
The other (missing?) part of that plastic extends toward the front and is secured by two wing nuts.  It alone is not enough to keep the tool kit in place on rough roads.

I have used duct tape (or even better 100MPH tape) to make a new hinge for the two pieces, which works for the short term.  Better would probably using small hinges found in the hardware store and fastening the two parts together.

Cheers,

 And thus another "best design possible" by the Hondagineers is revealed.

[TravisB]

Thanks TwoTired.  There is a nasty bump on 16th St NW that probably did this piece in.

[TwoTired]

Honda did eventually make a version of the tool pouch retainer in metal.  I believe my both my 77 CB550F and my 78 Cb550K have this.

My 76 CB550F still has the plastic one, still works fine.  However, the seat was replaced at some point, so I don't know for sure if what it has is original.

[Stev-o]

My '75 F has one in excellent cond

[TwoTired]

And thus another "best design possible" by the Hondagineers is revealed.

I don't understand what you are whining about.  You don't know why it failed or what someone did to it to make it fail, but still make a snap judgment?  I have a couple of those covers that still work fine, after nearly 40 years of use.  However, if you over stuff the tool compartment bay with "extra things", it puts way more stress on that built in hinge.  Anything that man can make, man can destroy via abuse or intention, no matter how it was designed.  Engineers often try to make things "foolproof".  But, there is always a new batch of fools trying a different way to screw things up.  Many engineers just can't think like fool.

Anything on the bike will break with just the right type of abuse.  And expecting man made sh!t to last forever (particularly sh!t made for the least amount of purchaser outlay), is a pretty strange concept, imo.  Buy a new bike and see how long it lasts, abuse or no.