One of the first things many riders change on their new Yamaha WR250R (or WR250X) is the handlebars. The stock handlebars are 7/8" in size and made out of chromoly steel. Most people will swap those out for a high quality aluminum handlebar, which is lighter and more durable for off-road riding.
You can read more about handlebars for your WR250R / WR250X here...
• SRmoto Yamaha WR250R Handlebar Guide
