With mountain bikes, the same thing has happened as with cars: there is a considerable technological difference between a model from 10 years ago and a current one. Bicycle manufacturers and brands dedicate resources every year to engineering and R&D to make rides on the bike more comfortable, faster, and safer. These are seven essential innovations that have changed the way we enjoy mountain biking.
Hydraulic disc brakes
A decade ago, this was an extra reserved only for the highest-end mountain bikes, but the fact that today they come standard on mid-range and even low-end mountain bikes is the best example of the importance of hydraulic disc brakes. Not only do they allow you to stop the bike's direction and movement in less time, but they also provide extra maneuverability, thanks to their hydraulic system that allows you to brake using just one finger. Today, they are a common component on most bikes and represent one of the major innovations that have come from the automotive sector to mountain biking.

Tubeless wheels
One of the most annoying issues you can have when going for a ride in the mountains is getting a flat tire. Until not many years ago, you had to carry spare tubes, a pump, and a repair kit with patches and gels. Also, stopping to repair a flat meant losing time and breaking your rhythm. There is no doubt that the arrival of tubeless wheels has marked a before and after in this type of incident. Just as with shoes in athletics, good wheels make all the difference in terms of handling, grip, traction, and speed going up and down. Tubeless wheels also allow you to keep riding even after a puncture, since the liquid inside seals the hole in the tire to prevent air from escaping.
Remote lockout forks
You might prefer them air, oil, or a combined system, but what is surely essential for you is having the lockout on the handlebar. We're talking about forks, a component that has also experienced a remarkable evolution in terms of technology. Another major innovation in mountain bikes came when brands started moving the manual lockouts of the front suspension to the handlebar. Not only do they provide greater comfort, but they also make it easier to adapt to irregular terrain without having to slow down or change your body position.

Dropper posts
Continuing with the chapter on suspensions, in recent years mountain bikes have significantly improved their riding comfort and safety on technical trails and descents thanks to the incorporation of dropper seatposts. Originally, they were designed as a complement to mountain bikes with central and rear suspension to make riding on long routes more comfortable and reduce back injuries. But they have ended up being so successful that some brands already offer them as standard on their hardtail suspension models. In enduro mountain bikes, they are an almost mandatory accessory not only because of the comfort they provide, but also for the safety they offer during descents, as they help lower the biker's center of gravity.
Oval Chainrings
This is one of the latest innovations to arrive in the mountain bike segment. Some consider it simply a passing fad, but the truth is that oval chainrings have a considerable impact on cycling performance. Their main feature is that, unlike round chainrings, where there is a point in the crank's rotation where no force is applied, with oval chainrings all the pedaling force is utilized. In addition, they reduce the pressure exerted on the knee with each pedal stroke, which translates into a lower injury rate. In reality, oval chainrings are not new. They were already used in road cycling in the 1980s. However, it wasn't until recently that they started to be implemented in mountain bikes as well, especially with the arrival of single-chainring drivetrains.
Lefty Forks
For now, they are exclusive to Cannondale, which installs this type of fork on its high-end mountain bikes, but that doesn't stop them from being one of the latest great technological revolutions in mountain bike. Lefty forks have both supporters and detractors when it comes to their aesthetics, since they have only one suspension arm. However, mechanically, they provide a notable improvement in maneuverability, flexibility, and torsion compared to conventional forks. That said, don't even think about letting go of the handlebars, because the bike will tend to veer to one side.

29" Wheels
For 30 years there was only one wheel size for mountain bikes: 26". And it seemed that no one had questioned whether it was necessary to change it. Until the revolution of 27.5" and, above all, 29" arrived. Currently, except in the case of downhill bikes and some enduro bikes, mountain bikes with 26" wheels are totally devalued and more and more manufacturers are eliminating this size from the models they launch on the market.