The clamp diameter is the outer diameter of the seat tube. Best to get a string and measure. If you have a 27.2 seatpost, the clamp will probably be 31.8.
__________________
"When you are chewing the bars at the business end of a 90 mile road race you really dont care what gear you have hanging from your bike so long as it works."
ΛΧΑ ΔΞ179 -
15% off your first Hammer Nutrition order!