I notice the first upgrade every does for an adventure bike is to put a big tank on their bikes.

Is a 12 litre tank enough (with an emergency 5 litre reserve can each).

The route we are planning on taking is UK to Turkey. Accross Iran and Into India then on to Nepal.

South east asia then touring Australia.

Riding the americas then back accross Russia and Mongolia.

This will give us an approx 200mile range with the total 17 litres.

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Bigger is always better. Even if you don't need it, at least you have options.

There's nothing worse than not being able to take the road less travelled because there is no petrol station.

Every long trip I've done I've had 'enough' range with 200 miles with only 2-3 times where I've had to carry a Jerry can or some coke bottles etc. I've always wished I'd had more though. It removes stress and head scratching from a route choice.

If you can afford it and don't want old pop bottles stashed all over the place just to go into a national park etc, then get a BIG tank.

Sadly, they don't come cheap but jerry cans are HORRIBLE to carry. They take loads of space, are heavy and are easily nicked.

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Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

In my opinion, a 200 mile total range would be fine most of the time but only if it were in the main tank. I think you'll want or need all of it more than you think and get really fed up with stopping for fuel or transferring from your 'reserve' tank.

I've had a number of bikes in UK with very small tanks - eg original XT500 with less that 10 litres, HD Sportster ditto, and it gets really boring to be stopping every 60 or 70 miles,(100km) and even more boring when you risk it and end up pushing.

And remember I'm talking about riding in civilised places here with reliable fuel stations less than 20 miles apart. Once you start getting into the wilds - and I even mean parts of Wales and Scotland, or France on a Sunday, let alone further East/South, you'll want all of your 17 litres plus a 5 litre reserve can.

My Guzzi (21 litres) and Tenere (23 litres) carry enough in their main tanks and give a true 200+ mile range which is fine for covering distance without stopping at every fuel station (ie there is some margin for error) and are ok for civilisation. If I'm heading off the beaten track, I bung an extra 5 litre can on the rack, though try and keep it empty most of the time, as the weight isn't really in the best place.

Bottom line: you'll probably be ok, but get a bigger tank if you don't want to be filling every hour or 2 and always worrying where the next fuel is, as you have little margin for error.

Personally I like to have a 300 mile range. this is because I live nearly 300 miles from the channel ports and sometimes it is not possible to get fuel between the ferry and my home.
This is easy to do with a car but not so with a bike. The BMW I had did about 50 ish mpg and I could get about 200 miles before hitting reserve. I never managed to put more than 18 litres into the 22 litre tank even after switching to reserve.
My Enfield does over 90mpg and I can guarantee 200 miles before needing reserve (240 if I switch over). I have never managed more than 12 litres into that tank. It is supposed to hold 14 litres. I hope to change it out for one of 18 litres which should give me my desired 300 mile range. It is time consuming searching for fuel, an ideal situation would be to be able to do a full days riding without -needing- to refuel. Even so I find I do more miles per day on the Enfield than on the BMW even though the BMW does more miles per hour. The difference is my ability to ride longer between fuel stops and to only stop for fuel in conjunction with some other reason.
I like to fuel up late in the day before finding a campsite. That way in the morning I have a free run until the following afternoon.

IMHO, it'd doable but in a few places you'll find that you would be using your emergency five litre every fill up, which can become a bit of a pain if you are using it regularly as opposed to just as an emergency.

In places like Mongolia, eastern Russia, central Australia, and South America there are times when you will likely need to carrying an extra five litres on top of the emergency five you have already.

I'd say the tipping point is frequency of use. If you can get away with rarely using your spare gas can then you have a large enough tank. If you would have to use it regularly, then you are better off getting a larger tank. I've travelled on bikes with a 23 litre tank, 22 litre, and a 16, I don't think I would go much below that for the places you describe.

Don't forget the mental side either. Ride until you are ready for a break then look for petrol all on the main tank, or find the perfect campsite on a Saturday night when you've got 150 miles left in the tank and you just ride and enjoy. Knowing you've got to top off the tank in case the only petrol station is closed means sitting there doing mental calculations. Worry about what a 40 mph head wind is doing to your fuel consumption becomes even less fun when the bike goes on reserve.

Andy

There is some truth in bigger being better but for the 600cc single cylinder old nails that I ride I've concluded that around 23-25L is optimum. Both the bikes came to me with much smaller tanks, one a 10L and the other a 13L and I toured much of Europe using them. Fuel was a constant worry, particularly during evenings, weekends or in the more remote areas and I've had to work my schedule round garage opening hours on a number of occasions. even to the point of sleeping overnight on a garage forecourt waiting for it to open in the morning.

For the XR600 I eventually ended up with additional 20L and 40L tanks. On the basis that bigger had to be better I put the 40L on but after a few trial fill ups it was mostly run half full. The main reason was that the bike is hugely top heavy with 40L of fuel high up - particularly when loaded with luggage, much of which is high up also and was just horrible to ride. Never mind that, just think of the range, I hear you say. Well, even in the Western Sahara where I thought it would be necessary, the furthest I had to go between fuel stations used just over 1/4 of the tank.

I now run the XR with the mid size 20L tank and that can give me a comfortable 250 miles with a bit left in the bottom. The CCM has an ex Paris-Dakar 23L tank with an additional 2L in a small container fixed to the rack. That's probably about right - enough range to stop me constantly worrying about the next fill up but not enough so that the weight bends the stand when it's parked on a slope.

The reason for my question is that the bike I am planning on using has a 12 litre aluminium tank. It would be pointless to spend the money on this machine then replace the tank as the tank gives much of the character to the bike.

We shall probably take 2 5 litre cans each instead of just 1.

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Most towns along the eastern side are close together. In central Oz, it's great to have 350km plus capacity. My Tenere (23l) allows me to do loops out around Alice Springs that have no fuel for 350km or a bit more - gives me a great amount of latitude. Some mates can't come with me as they only have 200-250km range. I don't like the idea of carrying extra fuel in containers, and will put up the with extra weight up front on the Tenere.

Fishing hooks......! A big 'un, catches big fish.. a small 'un catches small AND big fish!

reverse..........


Fuel tanks.....! A small 'un does small distance... a big 'un does BIG AND SMALL distances! Now it's up to you how much fuel/weight you put into it! Nay Bother!7

Here's another.........

Wise man say... "better to be looking AT fuel than looking FOR fuel!"

or a line from the band 'Pearl jam'..... "Gas in the tank is like money in the bank!"


I think you can see where I'm going........? LOL!

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Geoffshing

'Security is a product of one's own imagination, it does not exist in nature as a rule, life is either a daring adventure or nothing.'

I agree with Guzzibob that a 200 miles range is usually enough, I took your proposed route a while ago and carried on to Australia, with a 200 miles to reserve range I only once used it when an Iranian sent me the wrong way to the nearest petrol station.
The only places I have needed more is in Australia and Sudan.

Sorry to say it, mate, but I think there's a bit of 'form over function' going on here: I'm not immune to that myself, and I persevered with the original small (less than 10 litre!) polished alloy tank on my XT500 for years for just that reason, and earned grey hairs and blisters from worrying where the next fuel was, or pushing the bike to the next station!
As a number of other contributors have said, a larger tank gives you choices and really reduces the stress: dig out your Adv MC Handbook for confirmation from the 'master' - water equals time, fuel equals range. 2 x 5 litre cans will not only eat into your available cargo space, they will also do little for the aesthetics of your machine! If that's what you really want, why not get the Tank Shop (or similar) to make you a larger alloy tank? Be prepared to both pay, and wait a while though: I know people who have had to wait 18 months for their tank....

As in the rest of life, money can get you to the front of the queue -

The Tank Shop, Aluminium Petrol Tanks For Motor Bikes

You don't mention what bike you have but second hand Acerbis tanks for popular biles like the XT600 and XL600 come up on this site and Ebay occasionally, with 18/22 litre capacity and sell for about £100-200, keep your eye out for one.

The bikes were are planning on taking are 2 of these:

SR-40

There are good reasons for this:

Seat height: My wife is 5'3" and longer in body than leg so the CCM fits the bill. If we both take the same bike we don't need to double up on spares
Light weight: only 120 KGs
Engine: The DRZ 400 has been used on loads of trips on this forum

The looks are an added bonus, but I wouldn't want to change them so if I can run with the stock tank I would prefer it:

If i put one of these on the back of the bike it Might sort the problem:
Acerbis Auxiliary Rear Fuel Tank 6L

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