If you have read the previous post, you can probably tell the only way I want to extend the fuel range of the bike is by adding an auxiliary tank. So, what would that look like?
There are a few options I have seen around the forums, but I am only considering those that involve the bike, not the trailer. This, desirable option, would then allow me to travel, say 500-600km to visit friends wherever, with accommodation at the other end and no need to drag a bed, fork out for a motel etc. Or, I may just decide to do a long ride and come back home on one tank. Now, the fuel tank on the Spyder is just below and in front of my nuts. My bum is on the riders seat. My kidneys are about level with the pillion seat, which is just above that and behind me. So, anything above that is definitely higher than the fuel tank, which is ideal for gravity feed. If I can situate a tank here, gravity assist would be used to drip feed the main tank.
Now, what I have done here is add some colour to the above photo, to indicate my intentions. In the following modified photo, the small red circle is the location of the filler cap for the fuel tank. The violet is the approximate location of the existing fuel tank.
I would hate to ruin the rear seat and rear passenger hand grips, (yellow and green respectively). They would probably cost a bit to replace if damaged. So, I am thinking, can I buy a second hand seat that is damaged, (or undamaged for that matter), remove the actual seating material and then mount a tank to the underlying base plate? That seat, outlined in yellow above might be able to be removed and a tank situated there. There are a lot of wiring harnesses under that seat, so I would prefer it to be protected, but, in the end, it is a motorcycle, intended to be out in the rain. If it all got wet, the actual connections are waterproof and “should” be fine. I say should, but this machine has been built by a company that builds snowmobiles, used up in Canada in freezing arctic temps. A bit of warm rain should not be a problem right 😉
The green lines are the passenger handgrips. That is a height I know I can get my leg over when mounting, dismounting etc. If I could design a tank of suitable capacity, that fits here, that is quickly removable, then I am on a winner.
The gold coloured box further back is if I decide to remove the top box and mount a tank there and not dick around with the passenger seat area. It would have better benefits in that being higher, the drip feed would be faster, but maybe the fuel line may be more exposed? It would mean removing the top box(easy done). But, losing the top box means less storage. Decisions, decisions!!
So, I probably have two modification options to look at, that I am comfortable with, at this stage. There may be others I don’t know about yet.
- Remove the pillion seat and make/buy a blank cover plate, with tie down fittings and hose connections pre fitted, or a second hand dead seat and remove all the covering and just use the base plate????. This would be best if it could clip directly into the existing mounting system. That way I would not need to use the heated passenger arm rests as a tie down point. And for me, the pillion area is wasted space, no fat chicks on this ride. Yet!
- Remove the rear top box. The bike comes with a factory blank plate that fits here. I would just need to source that from where I bought the bike. It was too large, in its packing box, to strap to the bike when I picked it up last year. ** late update here, the shop has dumped all these cover plates from all the bikes they sold, so that option is out** Which is not a big issue because any tank I made to fit here, would weather protect what is underneath.
In the last few days, early August 2026, I have contacted BRP(Bombadier Recreational Products, the bikes manufacturer) directly asking for advice in this matter. Their response was basically “not happening”. Seriously, they were not rude, but had absolutely zero interest in directly getting involved. They directed me to my “local” dealership here in Rockhampton and said that their techs can send info requests to BRP that way. Yeah right! I bought my wheeels from a dealer 2,000km away. The local shop does not even sell the things. When I discussed the subject with the local tech, he basically backed away and said, nah, not getting involved!
I also contacted the dealer where I bought the bike. They were more friendly, but basically said, BRP do not have a good record of contact and that, something along the lines I want, would not be looked at. Because it would be modifying the vehicle outside of manufacturing specs. In fact, I did plead further with BRP and this is the exact response:
“Hi Richard,
Unfortunately, I have no other solution at the moment. SO sorry for the inconvenience.”
So there you go, direct from the horse!! You pick which end!
OK, While talking with Rowan where I bought the bike, we discussed my needs. He was quite helpful and could see nothing wrong with a gravity fed tank. He had some advice and warnings though of course.
- If I tried to “stack” the aux tank inline directly he considered it a hazard. What I mean by stack is, the rear aux tank which is higher, would continually drip feed into the main tank, fed via the breather hose of the main tank, with the aux tank, having it’s own breather higher up, so flow would be regular and not overflow the main tank.. He thought this was dangerous, I need to do some more research in this area, but I will heed warnings.
- He indicated that as the tank is not going to be connected in any way with the electronics of the bike, there should be no “nanny” issues(ie: the bike computer). He advised that if the upper tank was piped into the main tank then I could use an inline tap. When fuel gets low on guage, pull over, open tap and wait until drip feed fills main tank. Probably a good solution, I am always going to need a 5-10 minute break at some stage. Of course, overfilling could be an issue, so the aux tank would need to be smaller than main.
- If I use option 2 above, I have another option of adding the complication of an electronic, dashboard switch-activated solonoid, to open the drip feed once the fuel guage gives me the 3 dashes, at around 50km range. That means I could re-fill the main tank on the fly without stopping. This might be an issue if the outflowing fuel I use, as I keep moving, is less than the inflowing fuel feed, knowing there is still 5lt probably available???? I would need to monitor gravity fed fuel flow rates and compare. I might need to get my University fluid mechanics books out of storage eh!
Another point to consider, as mentioned above. If the tank guage gives me the old – – – then I probably have approx 5lt fuel left/35km range. The main tank is 26lt, so maybe a max limit on aux tank size of around 18-20lt. That way, if the aux tank totally empties, there should be no overflow?
Anyway, I have two viable mounting options available, so far. Doing the maths, using my 7lt/100km. Tank is 26, if I add an 18lt aux, then that is 44lt. 44/7 x 100 =628km. Now, that would be a good range, I could nearly get to Brisbane without a refuel 🙂
So, that is it for now. I need to find out if a second hand passenger seat is available, which to me, would be the best option, or how much a new replacement one would cost, plus shipping. I would keep the top box storage that way, which is the ideal solution.
I also need to talk to someone, about the actual material I need for the tank, probably aluminium.
…….TBC Hang Around for Part III eventually