I am (and have been for too long) thinking of just travelling on a bike through South America. The scariest thing for me (after committing) is how much money will I need. I don't need fancy hotels, or much else, just adventure and freedom to pick and choose where I might go next. Any advice on not only budgets but extra expenses would be appreciated

It's not how much money you need, it's what are you willing to do to make it happen. Don't let money stop you. Just go with the money you have and stretch your dollar and find out how stretchable you are and go back home when you run out of money.

A difficult to answer how long is a piece of string question and poorbuthappy answered it about as well as it can be, there will be unforseen expenses but by their nature are unpredictable. You don't tell us anything about what type of bike but the cheapest to run will be a small but new or newish model, some people get by alright with Chinese built ones but I would recommend a Brazillian built Honda.

Expenses ..
Living, eating/drinking .. will be more expensive that at home .. where you can shop for a week or 3 .. on a bike you don't have that storage capability so you have to buy the smaller parcels that cost more, and you don't know the cheapest shops either. But start with what it costs at home.
Living, accommodation - yep .. home will be cheaper. But you can get an idea of costs for these in the internet. Look at what you might consider and how much they charge. Consider YHA/YWCA etc too.
Then the transport?
There and back - air. Easy to get the costs for this.
Around about there ... will depend a bit on the bike .. but you can get an idea form fuel costs and estimated distances and fuel consumption. Then factor in oils, tyres too.

Add the cost for tourist sites .. and the occasional night out ..

Then ... add at least 10%!
And have emergency money ... for

My method has been to figure anticipated expenses, then double it. Recently I've gotten more realistic at estimating, and only need add 50% or so.

As an alternative, you could search this site for any of the threads in which we all argue endlessly about the answer to exactly your question. Some folks defend $25 US dollars/day; I'm more in the $80 to $100 camp myself. Much depends on whether you're including, for example, shipping yourself and bike across the Gap or from another continent...or the multiple thousands of dollars you might spend getting a bike overland-ready....or that "budget" trip to Antarctica, once you're in the neighborhood. Much also depends on whether you're moving along at a steady clip--in which case petrol alone might cost you US$50 per day in a place like Brazil--or spending most of your time lallygagging around in one spot. Then there's the camp-every-night option, the Couchsurfing option, and the "I'm in too much of a hurry to be picky about where I stay" option.

In other words, mileage, and opinions, vary greatly. Hope that's helpful.

Mark

I mostly drive 500 km a day avarage. The costs for gas, accomodation ie camping and making your own food varies. My average is about usd 50 a day in countries of South America and Asia. North America is more expensive.

I have the same question in my mind "How much money do i need?"
I've been three times in central asia and now i know that for living there (eat, sleep, petrol, cigarettes, few extras) i need from 30 to 40 dollars per day. Always sleeping in guesthouses, never tent.
I know that South america is more expensive then Asia, and i know that there are more things to do and visit, and i know that if i want to low down costs i need to use the tent at least half the time...
I wander if 50$ are reasonable (planning to go from Colombia to Chile)

Warin has a good answer to get you started:
- figure out how to get there - say $1000-1500 for a round trip air ticket, depending on your start and your destination airports, time of year, etc.
- figure out the cost of the vehicle. Are you going to rent, buy a small local bike, fly your bike in from overseas? A cheap little 125cc might cost $2000 US with paperwork and registration. Renting or buying might be a lot more.
- how much to take a tent, sleeping bag, etc.? How much are local hotels, according to travel guide sites? Even if you stay in cheap hotels, that gets expensive after a while, so camping will give you a lot more flexibility and save some money.
- food, fuel, maintenance will be lesser expenses, but have to be factored in. If your bike gets 50 mpg, and you ride 10,000 miles, that's 200 gallons at local prices $3 per gallon, more?
- miscellaneous: insurance, medical, park entrance fees, museum or other fees, etc.

Really, it's not rocket science to get a very rough ballpark estimate of how much cash you need. Grab a copy of Lonely Planet for South America or equivalent, get an idea of the rough expenses for daily travel, and you can build a rough spreadsheet from there of how much money you need.

Then remember this 'golden rule' for travel:
- put everything you think you'll need on a bed: clothes, camping gear, toiletries, and money.
- pack half the items...
- take twice the money...

__________________
Bruce Clarke - 2020 Yamaha XV250

I own a 250cc moto located in South America, so I have no moto rental costs. Purchase ($2500 US) not included in following costs. Two trips now, I traveled for under $40/day in Peru & Ecuador. That includes a room every night (no camping), food (restaurant/street food 2x, snacks for lunch), entry fees at several archaeological sites, moto expenses including several hundred $$US in repairs/maintenance. I was traveling almost every day. Does not include air fare (paid $650 US from northern Ontario/Lima/Hunauco round trip). Book your flight 3 to 6 months advance using Google Travel, and go in off season.

Chile is more expensive as I'm told, so I'll camp when I travel there.