Hot and Sandy

Travel writing, pictures and stuff for people I know. Quite a lot of cycling talk, and some semi-controlled ranting. Hiking, outdoor and two-wheeled stuff, perhaps a little computing when it's worth talking about. Meandering thoughts.

Wednesday, August 30


OK, so back to the graph. You can open it here, too.

The point is that in a race, graph 2 would be the most important - fastest rider wins. This is where geared bikes, shown on the red line, have a clear advantage. Especially in the zone c-f, the geared bike is much faster. But is life a race? Or is it more important to be one with the journey by maintaning a work-rate that is acceptable (adjusted by changing your gearing), and which directly reflects the landscape?

The blue line on graph 3 shows that the fixie rider remains in a small range - "the zone". Although the work rate is high when climbing, cadence limitations prevent the VO2 Max-derived wall that limits the speed of geared bikes. Each rider finds a compromise of cadence and strength. Likewise, the geared rider is a passenger on a freewheeling missile on the descent, but the fixed rider is kept warm by spinning down the descent.

Now look at the relationship between graphs 2 and 3. When the lines converge, riders are working hard yet travelling slowly, taking advantage (or taking shelter perhaps) in the mechanical advantage of gearing. When they diverge, riders are not working, but are travelling quickly. The blue lines remain a certain distance apart, and any elasticity in their relationship is because of the flexibility of the rider. New illustration of this here. This is the pleasure of fixie-dom in graphical form. Or something. :-)


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