I am 6' 2" and with the seat at the proper height, the handlebar is way too low for a comfortable riding position. After researching and considering different stem risers, new handlebars, etc, I settled on the Ritchey 4-Axis Adjustable Road/Mountain Bicycle Stem - BB Black . The size is 120mm/31.8mm. Once set to your preferred adjustment, the riser angle is locked in place, which to me is critcal for safety. I am very happy with the quality and result. I did switch the bolts from black to the stainless ones that came with our stock stem. I then used the black ones to fill the accessory holes on the frame. Looks better on my yellow frame than the stainless ones from sondors.
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Here is a pic