Sunday, April 26, 2009

Bicycle evolution indicative of overall technology evolution

The ever increasing pace of technology evolution is simply amazing. Examples of this are everywhere from communications(pony express to the pda in 150 years); engineering computation(sliderule to desktop workstations in 30 years); to audio(vinyl records to the ipod in 80 years). Step changes at the start of the 2oth century would typically take 2 to 3 human generations. Now 2 to 3 step changes are occurring within 1 human generation.
An example I'm very familiar with is the technology evolution of "upright" bicycles. The same basic derailleur bicycle had not changed from the earlier 1900's to the late 1970's. That vintage bike had brazed thin-walled steel tubing. Aluminum components. Two chain rings. Five rear cogs. Downtube mounted derailleur friction shifters. Leather saddle on aluminum seat post. Cleated cycling shoes with leather toe straps. Wheels were thin walled aluminum with typically 32 to 36 14 to 16 gage stainless steel straight or double butted spokes. Tires were either clinchers with tubes or the lighter weight glue-on tubulars. Jerseys and shorts were wool with a soft leather seat chamios. Helmets, if they were worn, were leather strap nets. Racing weights were 20 - 21 lbs. The speedometer was a wristwatch and road markers.

Today's model is a monoque carbon fiber frame and carbon fiber fork. Handlebars, seatpost, cranks, deraulliers, saddle cage and wheel rims all have carbon fiber options. Triple chainrings are common. Ten spocket cogs are common. Handbar mounted index shifting with integrated brakelevers are standard. Step-in toe cleats are used. Wheels can be monocoque 3 trispokes to 12 -15 bladed spokes. Even full disked wheels are relatively common. All components can be had in aerodynamic shapes. Spandex skinsuits with synethic chamios are common. Handlebar cycling computers with gps, heartrate monitors and training programs with downloadable databases are available. Aerodynamic, plastic shelled helmets with built in head phones are used. Electric hand and foot heaters are available.

The racing bike has evolved so quickly that the governing racing associations have had to implement weight and dimensional standards to slow the progress. For example the UCI (Union Cycliste Internationale) weight standard has been set at 15 lbs even though technology can provide weights a few pounds less than this.

In the early 1970's a time under an hour would win most 25 mile time trials including the US nationals. Today it takes closer to 48 minutes. Some of this improvement is due to better conditioning and more participation but the bulk of the improvement has been the equipment. Compare this to the 10,000 meter world track running record improving from 27:39 in 1965 to the current 26:17 in the same time period.

If the "upright" bicycle is compared to the broader field of human powered vehicles the analogy becomes even more amazing as shown by the hour records in the graphic.