Originally Posted by Lectron
Can you folks please read this. That what it's all about. SPEED RANGES.
You also have to think 'bout the chainline, meaning you don't use 34/11,12(&13)
What kind of speedrange is that ?
That's why I would never recomend compact crank.
Lectron, just becasue you have a 34 doesn't mean the speed range is slower. One thing you need to understand is that the cogs are smaller too.
I just plugged in the chainrings and cogs for 53/39 (12-25) and 50/34 (11-23).
If you are using 100 rpm, the speed range for both in the smallest chaings in roughly the same (withinin 1 mph)
Go plug it in for yourself
http://www.sheldonbrown.com/gears/ , Just because the 34 is phyically smaller doesn't mean that it will act like a granny ring...the cogs matter too.