2018 Trek models in stock now. The Trek Marlin 4 is perfect as an entry level bike and won’t break the budget at $529.95. The Marlin 4 takes its cue from light fast XC bikes. The right wheel size for each frame size, performance pedigree and an unbeatable ride feel When you’re ready for longer days on the bike, bigger challenges on the trail and all the fun of the full mountain biking experience, you are ready for a Marlin.