Originally Posted by bluegoatwoods
Very neat idea here.
One word of caution: I doubt very much if a bicycle could possibly get anywhere near 30 miles from a pound of wood. Even though I'm no authority on this, I just know that wood doesn't have that kind of energy density. Charcoal could be a bit better, but not all that much.
But this doesn't really matter. Anyone here who makes the attempt to build something like this probably won't be looking for mileage anyway. It'll be for the thrill and sense of accomplishment.
Entirely worthy goals, there.
Just be warned that there was at least some pie-in-the-sky in this thread.
True enough BGW
While petrol is expensive here in NZ I will freely admit that it's more about seeing if I could do it than anything else. My daughter's comment about it was, 'Wouldn't it be better to build a gasifier to run a generator and have an electric bike instead? That way you could use the gasifier to charge the batteries.' That is very much the electrical engineer in her talking though as she doesn't appreciate ancient two stroke engines in the same way as I do.
Wood gas does not produce the same amount of power as petrol and in fact running on wood gas causes a noticeable drop in power, but the advantage is that it's cheap fuel, or an alternative source of fuel if petrol isn't available.
For anyone wanting to run a charcoal gasifier on a bike the 'Simple Fire' gasifier is the best way to get your feet wet.
Thirty miles on a pound of wood though? - that is definitely fantasy.
Essentially all that is needed is the gasifier itself, a particle filter and modifications at the carburettor end of things
For a wood fueled gasifier things are more complex in that a cyclone type particle filter is needed, a means to cool the gas is essential and filters to remove wood tar are necessary before the gas gets anywhere near the engine. Removing tars from the gas is important because they are capable of literally gluing an engine up solid if nothing is done about them. The internal construction of a wood gasifier is much more complex too. The one big advantage about them though is that they can be persuaded to burn just about any type of biomass.