The Sonic Shoe Theory
AN: Jade here, I was just wondering, why do Sonics Shoes change in the games so frequently? Well I came up with a theory!
Well, after the events of Sonic the Hedgehog SEGA Genesis/Master Drive, Sonics original shoes had been burned up and was crumbling apart.
When Sonic meets Tails "Miles" Prower, a natural genius, he notices this and replaces his shoes with a flexible lightweight chaos reinforced soled sneakers that were resistent to flames and the grey trimmed bottom were specially designed for "friction".
There are no laces because if they came untied and Sonic tripped it would result badly if he was currently running quickly.
The shoes he wears are perfect and great for running at super sonic speeds. In Sonic Adventure and Sonic Adventure 2 the shoes are once again, redesigned by Tails to suit rail grinding needs (AKA, the Soap Shoe brand which are a brand of shoe that allow rail grinding with your feet.) but still represent same qualities but just aren't the same as his originals.
Tails notices this after Sonic Adventure 2 and replicates his first design again but the bottom now allows the ability for rail grinding and suited for higher speeds.
In the game series "Sonic Riders, and Sonic Riders Zero Gravity" Sonic doesn't need fancy suped up shoes because since he rides on a floating board similar to that of a skate board that uses kinetic energy to float, he can wear average sneakers that still represent some of the same qualities if he needs to run quickly.