Round vs Rectangular

#1
Hello aux fuelers,
I'm planning to add an aux tank to my '99 tiger to push range up over the 300 mile mark.
I like the spun aluminum tanks from Sandstorm but am also interested in something low profile and rectangular.
My question is what are your thoughts on using a cylindrical spun aluminum tank vs a rectangular tank? Obviously the advantage of rectangular is it fits in with other luggage well. The disadvantage is cost?

Also where do you find low profile rectangular fuel cells? I've seen some pictures of those that are maybe 20" wide, 16" long, 4" tall, but I have not been able to find any for sale. Perhaps they are custom made? Something like that would fit in nicely below my current relatively short top box if I am able to get my hands on one.
 

Uncle Zoom

Premier Member
#5
Unfortunately, just the opposite. I had them build me a tank three years ago and while I had to wait 4 weeks, there was no issue with just one tank being built. Too bad they changed their policy because it is a good quality tank. Sorry about that!
 

RobG4

Premier Member
IBR Finisher
#6
Unfortunately, just the opposite. I had them build me a tank three years ago and while I had to wait 4 weeks, there was no issue with just one tank being built. Too bad they changed their policy because it is a good quality tank. Sorry about that!
You were probably one of the last one-off customers they had then. I reached out to them in early 2022, and they told me they weren't doing singular custom orders any longer.
 
#7
The seals tank looks great but that is one hefty price.
I'm going to check in with some local welding shops I'm friendly with, but at this point I may just go with the cylindrical tank for simplicity's sake...
 

EricV

Premier Member
IBR Finisher
#8
The round tanks, including the Sandstorm tanks, are somewhat variable in actual volume. Can be over or under stated volume. Enough to get you failed at tech in the IBR. It depends on the end caps and cycle of the moon, from what I've heard. Keep that in mind when you pick a size. Make sure you've got the overflow fitting where you want it too.

The low profile rectangular tanks are all custom built. Design a frame or decide on mounting points and go talk to your local welding shops. Sometimes you get lucky and catch their interest. Let them know you will send more business their way if you're happy with the results. Remember to do the math accounting for the wall thickness of your material. ;)

There are some really good threads/posts here on various custom fuel cells and mounts. Do some searches and reading.

edit - @jcbrnld - In regard to Seal's price for their moto tanks. No, that's about what it costs in many cases. My first custom fuel cell around '06 cost $1100 and I sold it 8 years later for $1500. My second one was done by a very good friend, but was likely pretty close if I'd have been a full paying customer. Then I did a custom expanded OEM tank, taking it from 6 gal to 8.2 gal. All in, that ran over $1000 what with the tank, welding, fittings and a Rhino liner outside coating. Painted to OEM quality it would have been $1600.

All this said, you can roll your own at a pretty reasonable cost if you pick an off the shelf square-ish fuel cell from JEGS/Jaz/RJS/Summit or eBay and just fab or have fabbed the mounting plate. Or go with the round one, buy the off the shelf mounting brackets and again, fab a mounting plate.

Even if you're not planning on doing rallies, consider reading the IBR fuel cell rules. Cert rides have no rules on fuel quantity, you can carry as much as you want. Most endurance rallies stick with the 11.5 gal rule that the IBR uses.
 
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EricV

Premier Member
IBR Finisher
#9
Rhodes will also do custom tanks. Depending on how far away from one of their stock sizes, it may be pretty cost effective. You need to know what you want, where you want fittings, what type of roll over vent valve you will use, what non-vented filler cap you want to use, etc. in order to get an accurate quote and end up with a tank that will work well for your needs.

I keep a list of fuel cell goodies bookmarked to this day. I like the Kelch Rachet caps with a tether and non-vented. They have a manual vent release version now, but you would want to ask Warchild if that would pass IBR tech, if you were wanting an IBR legal set-up. No stuck caps, always easy to open and tethered, so can't be lost. They offer male and female thread versions. LINK for aluminum filler neck and cap.

If I did a non-competition fuel cell again, I think I might go with a Hagan or similar push thru cap. Bolt on neck w/cap.
 
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#10
@ErikV So custom jobs are going to be expensive no matter what... I guess I can't be too surprised.
That does make the cylindrical option attractive (though the tanks themselves are quite ugly).
I can easily fab a solid mount system for a cylindrical tank so that may be the way I go.
I will definitely be sure to comply with IBA regulations just in case I end up participating in a group event.
These "girly" Tigers have 6.5 gal tanks so another 4 from a 8x20 cylinder should be just right. I will, of course, test the volume with actual liquid before installing.
 

EricV

Premier Member
IBR Finisher
#11
I would suggest you look at your bike and decide how you will mount an aux tank. Where can you bolt to the bike, what kind of risers, if any, are needed to get the angle you want, etc.

Then buy some paper backed foam board at the dollar store and tape up a box the size you think will best suit your needs/tastes. I love cargo platforms on top of fuel cells. A flat bed aux tank gives you options for still running a top box or hydration jug on top if you want. Do the math on volume to determine your desired size, (remember wall thickness).

Once you have the dimensions and a mock up, know where you want your valve, overflow vent and which ones you want to use, fire off those measurements to Rhodes for a quote. If nothing else, it will solidify your budget needs to go with the round tanks. :) Or maybe it will result in the tank you'd prefer that gives you more options.

099E7251-5BA1-4F61-AD42-141D5E8125C6_1_105_c.jpeg
Note mag light holder on side, duct tape on neck, fence at front to prevent cargo from sliding forward, tie down slots, (wide enough for RokStraps, vent/overflow on neck, not on tank. Valve is at clutch side front corner w/a small sump to maximize flow. This tank has baffles too, no foam needed. And it's made from 4 pieces, excluding the neck, sump and risers/mount blocks for the flashlight mounting bar.
F5490C5C-E4A1-4E6C-9D58-2F4C9A11086C_1_105_c.jpeg
 

keithu

Premier Member
IBA Member
IBR Finisher
#12
It's worth noting that Sandstorm also does custom sizing for the same price as off-the-shelf, provided you start with one of their standard diameters. As Eric said, the capacity may vary depending on end cap style, so it's safest to target 10-11.0 gallons as your total capacity. You're pressing your luck if you target 11.5.

A benefit I wasn't expecting: The round tank makes an excellent back rest. I mounted mine in place of my Multistrada's pillion seat. When I put my feet on the highway pegs and lean back the curve of the tank is right there in the lumbar of my back.

I mounted it using aluminum 80/20 T-slot tubing bolted to the bike's frame. The 80/20 tubing is light, strong, versatile, and requires no welding skills. I have another thread here in the forum detailing a couple different 80/20 mounts I've made.
 

JON12A

IBAUK's retired Shop Keeper
Premier Member
IBA Member
#13
I must say that a lower profile rectangular tank does make for a great place for extra luggage stored on top of it. Many tank builders will weld eyelets on to the tank so that you can tether an extra bag etc.
 
#14
It's worth noting that Sandstorm also does custom sizing for the same price as off-the-shelf, provided you start with one of their standard diameters. As Eric said, the capacity may vary depending on end cap style, so it's safest to target 10-11.0 gallons as your total capacity. You're pressing your luck if you target 11.5.

A benefit I wasn't expecting: The round tank makes an excellent back rest. I mounted mine in place of my Multistrada's pillion seat. When I put my feet on the highway pegs and lean back the curve of the tank is right there in the lumbar of my back.

I mounted it using aluminum 80/20 T-slot tubing bolted to the bike's frame. The 80/20 tubing is light, strong, versatile, and requires no welding skills. I have another thread here in the forum detailing a couple different 80/20 mounts I've made.
keithu, I actually just ordered a custom round tank from sandstorm last night. One day maybe I'll get a sweet low profile one but for now i'm going the cheap and simple route.
I was hoping this would create a bit of a backrest so I'm glad to hear it worked on your strada!
I saw your thread on using 80/20 tubing to build a mount and am planning on doing the same for this tiger. I'm curious about which specific fittings you used to attach to the frame. Any chance you could send some photos of the multistrada setup?
 

keithu

Premier Member
IBA Member
IBR Finisher
#15
I'm curious about which specific fittings you used to attach to the frame. Any chance you could send some photos of the multistrada setup?
Under my pillion seat are four M8 bolts that thread into the subframe and support the rear fender and luggage. I simply got longer M8 bolts and used these as mount points for the 80/20 fuel cell frame. I drilled holes in the base members of the 80/20 frame and the M8 bolts pass through that before threading into the bike subframe.

I added some more photos to the 80/20 thread so you can see a little more detail of the Multistrada frame that I built.