Originally Posted by Trakhak

U brakes were used on mountain bikes for two or three seasons in the late '80's and then disappeared. They were fine (I had them on a 1986 Cannondale), but V brakes are fine, too, and are still used on many bikes.

There's nothing you need to upgrade on that bike.

Unless you want wider tires. Installation of tires that are as wide as can possibly fit a given bike is a current fad among Bike Forums denizens, but if it were my bike, I'd put in a few hundred miles on the bike as is and think about wider tires down the road.