Hardtail mountain bikes tend to be more lightweight than full-suspension bikes, as they usually do not have a rear shock absorber. As they want to be more lightweight, they can accelerate more quickly, but overall they are not necessarily faster. That’s because, while they may be more lightweight, they take more force to keep speed than a full suspension bike. Compared with full suspension bikes, hardtail bikes also are not as suited for downhill mountain biking.