You are saying 2 things here.
“regear” ... from what to what ??
“Stock tires” from what to what ?
if all you do is put larger tires on, your rpms will be less than they were with smaller tires. Do the math.
This is why we regear, to a deeper ratio. We want those rpms back, plus a few more to compensate the extra wind, weight and rolling resistance.
