Road Cycling - how to determine steerer tube size?

This is probably simple question with a simple answer but since I don't know I am going to ask. How do you determine the size of your steerer tube without removing the fork. If someone just happens to know what size the steerer is on a Cannondale R800 that would also be cool. Thanks again.

Add the length of your headtube, stack height of headset, stem and any spacers you might have.

If it's within a couple of years old, it's 1-1/8" diameter. To be sure, remove the top cap and measure the outside diameter of the steerer tube. You can do this without removing the entire fork, just the top-cap on the stem.

Or, you could remove your stem, and measure the inside diameter.

If it's a CODA stem, there are usually a set of numbers stamped onto it, that will give an indication as to the diameter, length and rise of the stem.

Or, are you speaking of steerer tube length?

Measure from the top of the crown (right where the bearing race begins) to the top of the stem and then subtract the amount to the top of the steerer tube. (You'll have to remove the top-cap again!).

L8R

BTW, you cross posted (posted same topic in two or more categories). We frown upon that as it can cause confusion, so I removed the other one!

Sorry about the confusion, maybe this will clear it up. I was referring to the diameter of the tube and I have a quill type stem. Thanks again

How old is the bike????

The best way in that case is to remove the stem, and the Top nut of the headset. That should expose some of the threaded portion of the steerer tube.

It's either going to be 1" or 1-1/8". Cannondale didn't make a 1-1/4", so it's one of the other two.

L8R

If it's a quill stem, chances are it could be 1". Since the quill is exposed, simply take a ruler and measure the diameter of the quill. If it measures just beyond an inch, it's an inch & 1/8.