This part raises the height of the handlebar 2-3 inches on a most modern bikes.
bikes made after 2000.
threadless stem Made of 6061 aluminum Height gain: 80mm (3 inches)
Extender clamps to steerer; stem clamps to extender
Adds up to 4-1/2" height to threadless steerer
Includes top cap and long bolt
40mm of threadless steerer is required for proper installation
Do not stack steerer extenders; no more than one steerer extender recommended per bike
Warning: Dimension Steerer Extender is not recommended for use on forks with carbon fiber steerers.