Sometimes I have bad ideas.

[nicksta43]

My wife will not ride with me. And she refuses to let my son ride with me as well. So the pillion seat is useless to me. I've often thought it would be a perfect spot for some on board storage. I seriously contemplated making a custom box out of fiberglass and almost went that route. However, I noticed Harbor Freight is now selling cheap Pelican case knockoffs and there medium sized box fits perfectly in that area. Just enough room for my daily commuting essentials in the summer (Lunch, sunglasses and such). The added benefit is that I don't have to design hinges and latches as that's already taken care of. The downside is that I'll have to figure out a way to make it not ugly.
 
I wanted to make it lockable so I set about re-keying the extra lock from my hard bags to fit the bike's key. Then I set about mounting it to the box. I had to fabricate a new latch arm and latch plate. I also had to modify the lock cylinder to allow it to mount with a spring clip. 
 
After those were painted and the latch plate riveted to the lid I set about mounting the box to the bike.
 
My goal was to not modify the bike at all. It has to mount exactly as the factory rear seat does.
 
 First order of business was to locate some rubber bumpers on the bottom of the box as that would allow me to locate the box correctly on the frame and allow me to properly eyeball the correct angle for the rear mounts. I bought some rubber plugs that are meant to go on the bottom of chairs an used those. On the rear they fit perfectly and I just bolted them to the bottom of the box.  On the front I had to make some spacers which I made out of some scrap 1/2" PCV pipe I had laying around. 
 
The rear mounts are simple. I took a couple pieces of 1/8" x 3/4" flat steel and bent them to the correct angle. I made sure they just touched the factory contact points with all four rubber feet touching the subframe. I painted then riveted them to the box. I covered them in some thick heat shrink tubing I had left over from another project to protect the factory contact points.
 
The front mount took some time to work out. I settled on a design and set about fabricating and some more eyeballing. After some test fitting and an extreme amount of luck it fit perfectly. Just enough tension to keep it securely in place but not enough to put any stress on the factory latch. It goes on and off just as easily as the factory rear seat and it locates perfectly every time. This is a major victory and exactly how I wanted it to work. 
 
Here are a couple pics of it on the bike.
 

 
And that's where I'm at currently. Now comes the hard part, figuring out how to make it not look like hot garbage. I've got some ideas, we'll see if they pan out. If not I'm not out much money and the stock seat just goes right back on.
 

[badballie]

This is an awesome idea , i do not ever have any one on the back of my bikes and have always wanted this .

[Guest kernowjim]

Useful but it doesn't do much for the bikes styling...

[wordsmith]

Like many here I also enjoy 'fiddling' creatively, and just love stories and pix like this!   Well done... 8-|

[BBB]

I too have researched how to make a fibreglass seat cowl for storage, but it’s in my “one-day, probably never” project pile. Your build idea is brilliant though as I had always wondered how to make a base that can slot straight on, but preserve the ability to reattach the standard rear seat. Thanks for the ideas.

[nicksta43]

Useful but it doesn't do much for the bikes styling...

 
 
No it does not. I'm hoping it will look a lot more integrated when I'm done but it's still not going to be sleek. To me though an integrated storage compartment will look much better than a bag strapped on, not to mention be much more secure. I've never liked the look of a tail bag nor a big rack hanging of the back with a big ol ugly top box. I don't mind the look of the side cases but they are excessive for the storage I need for my daily commute.
 
To be honest though I don't find the styling of the FJ-09 particularly attractive to begin with.

[nicksta43]

I too have researched how to make a fibreglass seat cowl for storage, but it’s in my “one-day, probably never” project pile. Your build idea is brilliant though as I had always wondered how to make a base that can slot straight on, but preserve the ability to reattach the standard rear seat. Thanks for the ideas.

 
 
I still may build one that way eventually. Especially if I can't get this one too look decent.

[2and3cylinders]

Why not obtain a 2nd pillion saddle and remove the cover and padding, spray it black and attach a small top case to it?
 
A lot simpler and easier, and probably cheaper when yor time is considered, and better looking!
 
Personally, I just bought a Nelson-Riggs seat bag that expands and fit like it was custom, came with a rain cover, and left it at that. Of course I have Shad SH46 behind it.

[nicksta43]

Why not obtain a 2nd pillion saddle and remove the cover and padding, spray it black and attach a small top case to it? 
A lot simpler and easier, and probably cheaper when yor time is considered, and better looking!
 
Personally, I just bought a Nelson-Riggs seat bag that expands and fit like it was custom, came with a rain cover, and left it at that. Of course I have Shad SH46 behind it.

 
 
I tried to find a used one but came up empty. I'm not paying new prices for one, but that was the original plan. If I can find one for a decent price I'll buy it and build the fiberglass box off of that. As for cheaper, I doubt it. I've got about $30 in this so far and that's for just the box. Everything else is scrap and leftovers I had from other projects. I don't count the time as fabricobbling is what I like to do. I'd I wasn't working on this I would have just been watching YouTube.

[pattonme]

gotta think outside the box. put your bike under the 3d printer gantry and just print yourself a fully embededded, perfect fit solution.
*ducks*
 

[phpaul]

"Fabricobbling" he sez... (rofl)  
Ima steal that.

[wordsmith]

Why not obtain a 2nd pillion saddle and remove the cover and padding, spray it black and attach a small top case to it? 
A lot simpler and easier, and probably cheaper when yor time is considered, and better looking!
 
Personally, I just bought a Nelson-Riggs seat bag that expands and fit like it was custom, came with a rain cover, and left it at that. Of course I have Shad SH46 behind it.

I tried to find a used one but came up empty. I'm not paying new prices for one, but that was the original plan. If I can find one for a decent price I'll buy it and build the fiberglass box off of that. As for cheaper, I doubt it. I've got about $30 in this so far and that's for just the box. Everything else is scrap and leftovers I had from other projects. I don't count the time as fabricobbling is what I like to do. I'd I wasn't working on this I would have just been watching YouTube.

BMW's iconic R1200 GS's also have a two-piece seating arrangement, and if removing the pillion seat more-or-less permanently a hard neat-looking OE cover can be bought and slipped into place.   Below are two pix of said device - fitted and underneath - on my last 2016 GS... naturally, being BMW-branded it's almost the price of a new Tracer!    
Some years ago on an earlier GS model with the same feature I fitted a small ~40L travel case of the carry-on-board airline type, which I found both OK from an appearance point of view and, more importantly, entirely adequate for all my needs on a ~15,000km/ ~five week circumnavigation of Oz.   FWIW...
 

 

[estell]

I've never liked the look of a tail bag nor a big rack hanging of the back with a big ol ugly top box.

I also don't care much for the look of the top box on the rear rack, but it is so darn convenient that I just accept it and use it. It will hold a helmet, groceries, riding pants, lunchbox...(not all at the same time).  I don't have to reach down to access it, and I no longer need to carry a backpack.  
My 39 liter box is big enough for 95% of my riding days. There are just a few days a year that I wish it was bigger. Then I add a tail bag and some soft side cases.
 

[keithu]

Nice work nicksta43, thanks for sharing! I keep thinking that I'd like to build an auxiliary fuel cell to mount in place of the pillion seat, similar to what you've done.

[joeszup]

I like it! Thanks for the pics.