Originally Posted by
Shahmatt
On 20" inch wheels you may just get more wear than larger sizes. Simply because there's less rubber involved.
How fast you go will depend purely on gear ratios. It has nothing to do with the wheel size.
Smallers wheels are less intimidating when navigating through pedestrians.
Smaller wheels have more sensitive steering. Easier to maneuver.
I generally agree with this.
Smaller wheels will have slightly higher rolling resistance than the same tire (at same pressure) on a bigger wheel. This is not a huge effect. I'm currently a couple mph faster on my 20" bike than my 26" bike (largely due, I think, to poor tire choices on the 26" - I'm more aerodynamic on my 20" bike).
For going fast, aero is most important, so finding a bike that lets you ride the same way you fit on a larger bike is important.