DIY Bicycle Hookup
Many Country Living Grain Mill owners are enjoying the pleasure of grinding whole grain flour, exercising and reading or enjoying an audio or video program –all at the same time! We hope to inspire you by posting their experiences on this page.
DIY exercise bike hookup from Carmen Wyman
The goal was a design that allowed more grain to be processed without tiring and to be able to continuously fill the hopper without stopping. It's an easy one person operation.
The mill is mounted on a common type of exercise bike that used a chain driven heavy iron flywheel with an adjustable friction strap on it. We removed the strap and modified a pulley to set between the small sprocket and the flywheel.
The mill is bolted to two layered pieces of plywood that can slide front to back to adjust tension.
The belt tensioner is a piece of threaded rod, a hook on a tube and the adjustable black handle. The belt length was determined by wrapping a piece of 3/8 inch rope on the pulleys and marking the rope where it overlapped. The rope was then removed and measured from mark to mark giving the length of belt needed.
The rear sprocket on the bike has 52 teeth and the front one has 14. That's a 3.7 to 1 ratio. So 60 rpm at the pedals (I recall this is a good natural pedal speed) jumps to 222 at the flywheel. From there the pulley which is a 6 inch gives a reduction of 2.5 to 1 up to the mill. The final rpm at the mill is 89.
Simply put, one turn of the pedals gives 1 and 1/2 turns of the mill. This is a comfortable workload for most anybody and delivers 1 cup of wheat flour a minute.