Yeah, but it was a little more than that :)
Here's what I did, for comparison:
4160D7 x_negative:
4160D7 cmp dword ptr speed_x, -1535
; I changed this to jmp short 0x41612F, effectively ignoring the max speed tests
4160E1 jge short x_positive
4160E3 mov dword ptr speed_x, -1535...