ProTaper JUNIT A25Y Youth Handlebar - 680mm 25mm Rise 31.8mm Aluminum Polished BLKProTaper A25Y Handlebar 680mm 25mm Rise 31. 8mm Aluminum Polish Black. For the JUNIT ProTaper mountain bike handlebar system ProTaper flipped the script. They began by determining the ideal grip diameter and worked inward. The result is a handlebar and grip thats ideal for a smaller ergonomic profile. JUNIT ProTaper handlebar and grip are designed to be used together. For an element of added safety the grip utilizes a built in bar plug that will never