The force of man

When dealing with engines you often mention horsepower and torque. Higher numbers makes people impressed. But we should think of the power in our legs to. There is power that is not seen or noticed so often. But when on a bicycle and you start to think about it. It is your legs that makes the wheel turn. Up the hills, down the hills. In rain and snow. The legs keep on peddling. But with an tandem bicycle there is two people peddling. Twice the normal power on a bicycle. Imagen the force when going up a hill. The chain, wheels, bearings pedals, cranks. Everything needs to be in good shape for making it up the hill.
I have experienced a chain failure while going up an hill. Even an crank shattering, going up a hill. Or an pedal snapping right off from the crank.

With all this in mind I started to take the front crank to pieces (the crank wobbled, most likely a loose bearing inside). But when I got the covers off I discovered that the small balls in the retainer was missing, the retainer itself was all bended and scratched. This is looking really bad.
I dismantled the rest of the crank and bearings. It turned out that all balls had fallen out the retainer and where in the bottom of the crank housing. The balls was all badly damaged and unusable. The bearing shell was looking strange. As it turned out, it had shattered. It was in two pieces and all cracked. Metal parts from the shell where all over the bearings and crankshaft. All the grease inside was filled with small metal parts.

Luckily bearing shells are somewhat an easy part to find, it all depends on the treads. Since the tread is going against the directions of rotations. There is one for left side and one for the right. It is important to remember this when repairing bicycles. Since the old “righty tighty – lefty loosy” do not apply. There you can thinking that you are loosing the part you are swearing over. When you in fact are tightening it all.
So I made an visit to the special vintage bicycle shop in the city. The old gentleman in the shop pulled out an old drawer and some money later I had an old but unused shell in my pocket. Back home, it fitted right away. So now it is an matter of cleaning the old parts from all old 1940’s grease and metal parts from the old bearing shell.

The pure power of two persons peddling up an hill made the entire bearing shell shatter. No need for an engine. Tandem bicycle and fresh air and strong legs are a good combination so it seems.


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