Although it depends on the materials of the frames and the extent of suspension, mountain bikes are undoubtedly heavier than any other type of bike.
A mountain bike’s average weight is 30 pounds (compared to 17.5 pounds for the average road bike). While mountain bikes may be heavier than many other types of bikes, the weight is still important, and the main reason people upgrade components is to shed that weight.
Hardtail Mountain Bikes
The lack of rear suspension makes hardtail mountain bikes your lightest option. They are built to be lightweight and relatively simple.
Perfect for cross country racers or occasional weekend riders looking for a relatively fast but uncomplicated mountain bike.
Full Suspension Mountain Bike
The average full suspension bike comes in at 30lbs to 34lbs!
The addition of rear suspension adds weight but also comfort and versatility. They usually have a unique frame geometry that increases the weight of the frame, in addition to the extra weight from the rear suspension mechanism itself.
Downhill mountain bikes are generally the heaviest of the bunch, averaging around 35lbs. This is due to their purpose and requirement for added stability and protection when careering down the side of the mountain.
How important is the weight of a mountain bike?
Unless you are at the absolute peak of your physical fitness, do not obsess over the weight of a mountain bike too much. Instead, look for reliable components and quality frames. Yes, a reduction in the weight of a mountain bike can help improve performance, especially uphill.
However, you are better off losing a few pounds from your belly rather than spending hundreds extra to shave a few pounds of the bike.
If you feel the need to shave weight off your mountain bike, you can upgrade your wheelset, go tubeless, get clipless pedals, upgrade to a 1x drivetrain or invest in a full carbon fiber frame.
The lighter the frame, components, and parts, the more expensive they are likely to be.