No aftermarket. everything is bone stock.. When the weather warms a bit I'll swap out another old speedo unit and see where that gets me. It's not shakey or anything. just reads 10 mph slow. I measured the tire/wheel compared to an old one in the garage with an old old tire on it and my new tire is almost an inch smaller in overall diameter, but that should make the wheel spin faster, right? anyone had the drive in the hub wear out?