The road from Koplik to the Qafe e Terthores Pass is narrow, but paved, and climbs up, with many switchbacks that are a blast to navigate.
However, the last 50 km of this route from the pass down to the village of Theth and the Theth National Park is a very dangerous mountainous trail that should NOT be attempted by novice off-road riders. DO NOT ride this road on street tires, and DO NOT ride if it's muddy. Look at the photos; there are few, if any, guard rails to keep you from tumbling to your death if you veer off the very bumpy road.
This stretch is only open from late May through September, maybe October, due to high-altitude snowfalls in the winter.
The payoff is fantastic, though, as the Theth village and National Park are glorious to explore, with its a raging, wild river, several nice waterfalls, and alpine valleys filled with beautiful flowers, all surrounded by towering mountains that the locals call the Accursed Mountains (really a portion of the Albanian Alps).