Over-tightened headset = my 2 penneth. Check by standing your bike level and straight, and simply turn your handlebar left 90 degrees,
then right 90 degrees. Turn at different speeds, from slow to medium to quicker. If you hear squeaking, then you've found the answer.
Or, if could be the hub is over-tightened also, as mentioned above.
Over-tightened headset = my 2 penneth. Check by standing your bike level and straight, and simply turn your handlebar left 90 degrees,
then right 90 degrees. Turn at different speeds, from slow to medium to quicker. If you hear squeaking, then you've found the answer.
Or, if could be the hub is over-tightened also, as mentioned above.