Thank you for your question.
Pain around the tip of coccyx
is called coccydynia
. This results from sitting for prolonged times. The episodes are usually self limited. The best measure for this is preventive- try not to sit for longer times. If you have to- take frequent breaks in between. The back and neck pain
fro bike riding is most probably muscular in origin. Correct posturing and lifestyle modification to limit bike rides may be helpful.
Wish you the best.