The phrase "bigger wheels" means having larger or more important goals or ambitions. It suggests aiming for something greater and reaching for higher achievements. Full definition
It's a push model with big wheels that make it easy to get around. (geekwrapped.com)
The canopy is a bit higher compared to similar stroller, maybe because of bigger wheels, which makes this stroller preferable to children as well. (childstrollers.com)
We are looking for bigger wheels to raise the height some. (theinspiredroom.net)