Originally Posted by Carusoswi
Al, you mentioned changing the wheel size from 27" to 700c.
27" wheels haven't been used on new bikes for quite a while - certainly for over a decade and maybe even two. Consequently, every year that goes by, tire and rim choices decline by a model or two. Mavic, for example, hasn't made 27" rims for around 10 years.
That aside, I wouldn't fret excessively about wheel size. Larger diameter wheels roll over bumps more easily and smaller diameter wheels are more durable and aero. Within the 26" to 27" window that we're all used to you'll have to use some kind of instrumentation to detect the difference.
Changing wheel size on a bicycle can sometimes be done pretty easily but there are trade offs. You may have brake reach issues or tire clearance issues. It will raise or lower your bottom bracket slightly and change your gearing and handling a bit. It may also look goofy.