By David Ponce
Holy Jeevus and all that stuff! A steam powered bicycle! This four year old design by Geoff Hudspith just now comes to my attention, and I, for one, think he deserves a pat on the back. One, for the bike. And two, for the wonderful hairbun.
His creation is powered by paraffin, aka wax and averages 6 – 8mpg of water and about 60 – 70mpg of paraffin (at a guess).
I made twin top bars to support the paraffin tank and strengthen the swan-neck frame. The engine is pivoted from the fork crown to allow the front forks to flex in the normal way, and the chain tension is kept constant by struts down to the front wheel spindle. The transmission chain runs from the crankshaft sprocket to a chainwheel, filed out to fit a Sturmey-Archer 3-speed AW hub, giving a ratio of 5.33:1 which can be increased by 33% or lowered by 25%. Also, I have a neutral position between 2nd and 3rd gears, by using a friction lever to control the gear cable. This is useful for warming up the engine initially, and for stating and stopping.