A hardtail mountain bike is cheaper and easier to maintain. For a first bike, these are huge benefits over buying a full suspension.
But the biggest benefit is that hardtails actually teach you how to ride. An over confident beginner who’s only been on a full suspension will often struggle on advanced trails. They have difficulty because they’re used to letting the bike do all the work. They don’t know how to properly shift their weight and use their legs.
On a hardtail you actually learn how to ride.
Proper body positioning and line choice is absolutely essential for a hardtail mountain bike.
To put it another way: you’ll learn how to ride competently quicker on a hardtail than a full suspension. You won’t find yourself getting in over your head, because a hardtail provides such instant trail feedback that there is no “cheating” or “floating down” like there is with a full suspension.
A hardtail mountain bike reacts quicker in turns. Full suspensions compress and bog down in corners. They can wander as the suspension dips and bobs. As a beginner it can be tough tuning your suspension to suit your style of riding.
Now, people will definitely say you’re crazy for considering a hardtail as a beginner because it is a “harsher ride” than a full suspension.
For this point, keep in mind that a key technique for descending is to drop your seat and hover over your bike, almost standing, while the bike works beneath you (see the picture above). On a full suspension this is straight forward–just stand off the seat and everything floats under you.
On a hardtail mountain bike your legs work a bit harder because they flow up and down with the trail, instead of an expensive rear shock. But this just means you’re learning better technique which will pay off down the road. You’ll be better for it and miles ahead of you friends that don’t learn this skill.
To put this clearly: a full suspension does most of the work; on a hardtail you do more of the work.
Very rarely will you sit down on descents. But I should note: if you do sit on a hardtail while going down a trail, it will be bumpier than a full suspension.
Lastly, one of the biggest surprises for most beginners–the amount of physical work it is to climb a trail–is less of an issue with hardtails. The solid rear end instantly translates your power to the ground, making your pedalling more effective (i.e. easier) than a full suspension.
Biking has many assumptions–and the assumption you can’t be on a hardtail is one of the biggest.
If your friends or the bike shop insist you start on a full suspension, take the time to make your own decision. Demo a hardtail and a full suspension. The full suspension may feel more comfortable but the responsiveness, simplicity, affordability, and better components of the hardtail should be kept in mind.
Lastly, if you’re on a hardtail mountain bike and your friends are on plush full suspensions, you get automatic bragging rights!