The Bike Hive

This posting is a shortened version of a technical paper I wrote for work. I hope you enjoy, and learn in the process! At one time, all bikes were made of steel.  Steel has been popular thanks to its strength to weight ratio and ease of use.  These factors as well as it’s low cost and availability make it ideal for use in bicycles.  The most common type of steel used for bikes is chromoly , and 4130 chromoly is the most widely recognized.  So what does chromoly mean and what do the numbers 4130 refer to? Steel is an alloy of iron and other metals.  The term ‘alloy’ is commonly used to refer to aluminum but it actually refers to any metal that’s mixed with other elements in order to achieve the desired mechanical properties such as strength, weight, durability, hardness, weldablitly, etc.  ' Chromoly ' refers to a specific type of steel alloy that combines Iron with Chro mium and Moly bdenum (chro-moly, get it?) along with small amounts of oth...

For many years, I've heard older people say that inner tubes don't hold air as well as they used to.  It's usually the same thing - 'I never had to air up my tires when I was a kid.'   Others seem to think that tubes puncture easier now than they did even 15 or 20 years ago.  All of this got me wondering if there really is a difference between the quality of tubes and if it's changed through the years. First, a (very) short history:  Originally tires and tubes were made from natural rubber from the Hevea tree that is grown almost exclusively in Indonesia and Malaya.  During World War II, Japan had invaded these countries and cut off the world’s supply of natural rubber.  This led to a shortage and the need for an alternative.   At the time, German engineers had already been working on a synthetic rubber, but it wasn't until 1942 that U.S. engineers were able to develop it into a useable rubber compound called Butyl.   Butyl synthetic rubber...

Kashima coating is a feature currently only found on Fox forks and shocks*.  It's easy to spot from it's distinctive dark brown color.  What is it and why do they use it?  First, a quick definition: Anodizing is a process by which a metal part (normally aluminum) is electrically charged and submerged in a chemical bath.  This creates an oxide layer that penetrates the metal and changes the microscopic texture and the crystal structure of the metal near the surface.  After a part is treated, it can be dyed to give it color before it is sealed to increase durability. Hard anodizing is a similar procedure that penetrates further into the metal. This increases the surface hardness of the material making the surface even more durable and corrosion resistant.  It does not make the metal part stronger, it affects the durability of the surface of the metal. Kashima coating is a type of hard anodizing that involves a lubricating treatment as well.  This ...