Originally Posted by
Branko D
The "I changed my wheelset and the tires and the bike was totally different" being pegged on difference in wheel weight is strange.
No, it's not strange at all - it does change the
feel of the bike significantly, not because it's going faster, but because it's easier to move around underneath you. Particularly when accelerating, people tend to get out of the saddle and rock the bike side-to-side - lighter wheels make the bike less resistant to this movement (this applies to cornering, too).
If you want to demonstrate to yourself, take a wheel off your bike, holding both ends of the skewer/TA, give the wheel a good spin and make note of how difficult it is to tilt one way and then the other. Next, take off the tire and tube and do it again - dollars to donuts, it'll be noticeably different minus that few hundred grams. If you want to stick to maths, rather than practical demonstrations, I guess that would fall under flywheel weights and moment of inertia, but I'm no physicist.
As I said previously, I don't believe that these kinds of differences will demonstrably improve speed, 'specially solo over a given course, but will they make the bike feel totally different? Absolutely.