Auxiliary Cell Design

[Duster19]

Interested in following this thread on Gen. 1 options. For nothing more then the looks of it, I also like the Tanji style. I do think the Linda's Custom Aux. tank covers are sweet too.

Dave

 

[madmike2]

1.) Dean figured out an ingenious mounting system; I'm not comfortable ripping off his idea

I'm not sure Dean would mind. Since he's decided not to pursue this anymore, it's not like you're eating into his profits. If you like what he did and would like to use it, I'd encourage you to contact him and ask.

Really!

Dean's system is ideal: simple and easy to use. One bolt and a quick disconnect and the bike can be converted back to OEM condition in about 15-20 minutes (re-install of the OEM or Givi rack).

Because the tank's location is low the transfer rate isn't as quick as the others shown above but, as a former detracter of the tank, I love mine. And I found a way to mount my Givi top case on top of the Tanji cell by having a friend build me an "H" shaped frame that bolts through the cell flanges. DougC has done the same thing and preceded my idea by a couple of years.

 

[Canadian FJR]

"I'm going to build a GenI auxiliary tank"

LOL, timing is everything..............I just bought a tank today.

Good luck with the new design.

Canadian FJR

 

[Joe2Lmaker]

timing is everything...

So true!

On the other hand, I only have to make one and that one is sold.



It's not much, but it gives me something to do during the winter.

 

[Duster19]

Are you going to keep us updated on the design you go with and the cost?

Thanks,

Dave

 

[Joe2Lmaker]

Are you going to keep us updated on the design you go with and the cost?

Absolutely.

Updating this thread also helps get me through the winter.

 

[FatNakedGuy]

I'm in!

 

[pmspaul]

Any updates on the Gen I tank?

 

[Joe2Lmaker]

I'm working on the bracket. I made a template of the oval holes in the rear subframe and I have a couple of ideas.

I don't have any photos to share, but I'll try do describe what I'm trying out.

There is enough room under the seat to leave part of the bracket permanently attached to the bike. When I discovered that, I thought 'cool!' 'seat comes off, tank attaches to a bracket that's already rigidly attached.'

Next, I thought about boxing in the area under the the tank. Now, I'm thinking that if some sort of containment needs to be attached to the permanent bracket, I haven't gained much. The plan should change to: remove the seat, attach the bracket/container and attach the tank. I think I have the two sides figured out.

I'll be making parts in the next week or so and posting some photos. The bracket should work with the OEM grabrail or the Givi rack.

 

[pmspaul]

I'm working on the bracket. I made a template of the oval holes in the rear subframe and I have a couple of ideas.

I don't have any photos to share, but I'll try do describe what I'm trying out.

There is enough room under the seat to leave part of the bracket permanently attached to the bike. When I discovered that, I thought 'cool!' 'seat comes off, tank attaches to a bracket that's already rigidly attached.'

Next, I thought about boxing in the area under the the tank. Now, I'm thinking that if some sort of containment needs to be attached to the permanent bracket, I haven't gained much. The plan should change to: remove the seat, attach the bracket/container and attach the tank. I think I have the two sides figured out.

I'll be making parts in the next week or so and posting some photos. The bracket should work with the OEM grabrail or the Givi rack.

That sounds very interesting. Is there still the potential for a short production run, or will this be more of a one off?

 

[Duster19]

I'm hoping this will the first thing I spend my tax return money on.

Keep us posted. I like the idea of the area below the tank to have some kind of weatherproofing (what I think you meant by boxing it in).

Dave

 

[Joe2Lmaker]

That sounds very interesting. Is there still the potential for a short production run, or will this be more of a one off?

Actually, we just talked about that last night. I told the gentleman paying the bills that I would make whatever he wanted, but reminded him that making one tank for him would be more expensive than making several and spreading the costs out a little.

Actually, I'm surprised he hasn't chimed in yet. If it wasn't for his GenI bike, in such a close proximity to my house and located in such a cozy warm garage, this project might not have been kick started again.

 

[Joe2Lmaker]

You might have to squint to make out what's going on in this screen shot, but this represents a helluvalotta reverse engineering work:

Progress. Not always fast, but we'll get there. I'll add the subframe ovals later. I need a beer.

 

[rogdeb]

I wish I'd started reading this thread in Aug '07 at it's inception (just read from post #1 now).... fascinating reading ! .. even though I don't need a fuel cell.

 

[Bounce]

i haven't seen any of the updates since my original reply. i never knew the Gen2 version went into production.

 

[Duster19]

I'll be honest Joe... I have no clue what I'm looking at, but happy you're working a Gen. 1 option.

Dave

 

[Joe2Lmaker]

i haven't seen any of the updates since my original reply. i never knew the Gen2 version went into production.

You missed out on the most dramatic parts! It turned out that the tank interfered with the seat if the seat was in the low position, and there is enough variation between GenII rear subframes that some custom grabrail bushings needed to be made. Oh, and how could I forget the tack weld problem! Poor 01VFR had the misfortune to discover all of these problems. <Link>

I try not to be thin skinned, but all of that really knocked the wind outta my sails.

It feels good to be working on this again. I think the GenI guys are really going to like this next iteration.

I'll be honest Joe... I have no clue what I'm looking at, but happy you're working a Gen. 1 option.

Dave

The screen shot is a wire-frame model of the critical attachment points on the GenI OEM grabrail. The geometry is not critical for the GenI tank, but it is useful to understand the relationship between the grabrail and rear subframe. Later, I'll add the oval holes in the rear subframe. I need to keep open the option of a rear subframe brace for GenI owners who choose to run without an OEM grabrail or a Givi rack. An internal brace will really save those people!

 

[Duster19]

Sounds good to me. Looking forward to seeing more update/pictures.

Dave

 

[allrider]

Pretty cool, but a couple of thoughts:

1. Fatigue is the enemy of sheetmetal. The fatigue crack in this design will form where the curved surface is welded to the flat surface. Try real hard to avoid welds in general and especially at right angles to a big flat surface like that. Suggestion #1: Make the top, front, two sides, and rear of one piece with gentle bends (CAD is a great resource to get the vertical corners right), then weld on the bottom. Suggestion #2: Make the entire Z-shaped bottom of a single piece. Give it a good half-inch or more of bend radius where your current sketch shows the bottom and top of the curved part.

2. Sheetmetal tanks are commonly held down by straps, because people long ago realized that cracks form at the edges of mounting tabs or where the wall thickness changes abruptly. Think carefully about how you'll hold the tank down. Also think about fatigue in terms of any tabs for light brackets, cargo tie-downs, etc.

3. Explosafe or any of the other foams are generally well-recognized as baffle material, but you'll need to check the IBA rulebook to make sure.

Hope this helps.

Bob

Fatigue is the enemy of riders too. I don't know how you can stay awake riding more than a couple of hours without getting off and stretching at a fuel stop. Put 10 gallons on a bike and you will want to ride the 5 hours till the next stop.

I don't know why they call it iron butt. It makes mine into marshmallow.

 

[Joe2Lmaker]

Just to clear up what that CAD screen shot represents, here's a photo with the grabrail in roughly the same orientation:

Next, I made a tool so I could find the location of the threaded holes in relation to the oval holes in the rear subframe:

... and a transfer punch:

The the tool was placed over the oval holes in the rear subframe, making contact with the point of the transfer punch. A gentle rap on the back of the tool and I have all of the dimensions I need to make bracket supports.