Stem sizes question

[cashconverter]

Hi everyone,

I want to replace the stem on my bike with this one here,

http://www.chainreactioncycles.com/Models.aspx?ModelID=8877

But I'm not sure which one to order, what does the 40mm, and 50mm mean?

Is it the thickness of my handlebars?

Basically - what is the difference between the 40mm stem in the link, and the 50mm?

Thanks everyone

[Bill]

This may help you out. http://forums.bikeride.com/thread-620.html I am sure someone here will give a better answer then me.

[Jordan300]

The 40 and 50 mm is how far out the stem extends from the steerer tube. The 28.8 and the 31.8 are the handlebar thickness. by the way, that stem is sweet lookin. Post a picture after you get it on there, I'd love to see it.

[Bill]

Thank you Jordan