Originally Posted by
arcadiantri
thanks for the insight treefox. why would a 53/23 hurt the chain? im usually 52/19-23, mostly 21, i just strive for 18+ mph on average during my races.
What treefox is referring to is cross chaining. The greater the diagonal created with the chain ie Big front chainring and rear cog closer to the spokes puts more stress on the components and greater wear.
Check out a gear calculator such as
http://www.sheldonbrown.com/gears/ and input the cassette ratio and front chainring sizes.
The resulting table will show you the gear inches. 53x23 is only a fraction taller than 39x17 which will have the chain running in a straighter line which means less transmission wear and due to the less friction within the components less wattage required for the same speed.