Manual Trainers

RAD resistance trainerManual trainers that are not controlled via software from your mobile device or your PC are often called "dumb trainers". They're not specifically dumb, they're just "unsmart", when compared to their smarter cousin the "smart trainers". 

Manual trainers are a class of stationary trainers that have a roller or resistance unit, but control their resistance via pressure on the tire which is manually adjusted with a knob or lever mounted on the handlebars of the bike. This also includes stationary bike "rollers", which typically do not have a way to control their resistance from the PC or mobile device. However, nothing beats the experience of riding rollers if you want true outdoor simulation while riding indoors. 

Kreitler Fixed RollersWith rollers though, there is a upper to how much power you could put down on the pedals. If you were pushing hard, eventually you would spin out even your largest gear. If you tried to add resistance to a roller unit, you'd end up riding your bike forward off the front of the roller or the back wheel would skid and slip on the roller drums. To address this, some manufacturers have added a front fork mount to hold the bike in place, or a rear dropout support to prevent the bike from shooting off the roller deck. 

dumb trainer, manual trainer