What is the appropriate tire pressure (PSI) for a road bike? Inflating to 120PSI currently. What is the acceptable range?
Tire Pressure
It depends on the road condition .....
When the road is wet during or after it rains… try inflating your tires to about 110 – 115 psi range for more traction and better handling. This way you are able to stabilize the bike more effectively.
If the road is dry and you want to go all out by going fast… try increasing your tires to about 120 – 135psi.
Also, be advised that some tires can only hold certain maximum pressure. Check and make sure the specifics of your tire model which is recommended by that manufacturer.
"""whatever is on the sidewall of your tires""
Proper tire pressure depends on many factors including rider's weight, tire width, road conditions, etc.
Heavier riders will need to use higher pressure, especially when using narrow tires.
Heavy riders and/or folks riding on rough roads would be well advised to use 25mm tires as a minimum.
See:
http://www.sheldonbrown.com/tires.html#pressure
and
http://www.precisiontandems.com/photos_files/tirechart.jpg
""Chainwheel"""
The acceptable range is written on the sidewall of the tire...where in that range will be dependent on the other factors previous posters have described.