A big category to cover electric mountain, trail and fat tire bikes. These bikes are made to tackle the hardest rides in the mountains, trails, in sand, snow and mud. 

Mountain bikes - Made for well... mountains. They have suspensions in the front and rear. They are mostly used for going up and downhill.

Trail bikes - Very similar to mountain bikes but their suspension has a longer travel distance which makes them great to ride downhill.

Fat Tire bikes - These bikes are made for trails, sand, snow and mud. Some of them have a suspension in the front. A rear suspension is very rare. All of them have FAT tires which makes them perfect if you want to tackle different terrains.