Boy am I slow...

[Veronica]

Will helium in my tires make me faster?

I just got red tires. Red is a faster color than gray, right?

V.

[maillotpois]

From Sheldon Brown:

CO2 is heavier than air, you will make your bike heavy and slow if you
use it. Helium is lighter, the only way to go if you want speed and
safety.

If you are willing to live dangerously, Hydrogen is lighter and cheaper
than Helium, but don't smoke while riding your bike if you use
Hydrogen...