the delay() function does not disable interrupts, if that was your question.
it seems to me that there is no good reason for the delay there unless you are concerned that the rotation of the wheel if VERY fast and 10 rotations occur faster than your serial transmission (and then you have another problem here). you would be adding to the serial buffer faster than it could be processed. Serial is slow, but maybe not that slow.
If that is the case, you can change your loop() to calculate on a larger number of rotations, therefore updating your XBee less frequently.
try it without it and see what happens.