Resistance is provided by three different types of mechanisms. The roller that is driven by the bicycle's tire can actuate a fan blade that uses wind resistance. These are usually the least expensive, but they are the noisiest of trainers. Another mechanism uses powerful magnets for resistance and is somewhat quieter. The last has a fluid-filled reservoir with a fan inside, which drives against the fluid instead of air. Fluid-based trainers are the quietest and most likely to simulate a true outdoor riding experience.
Bicycle trainers are constructed so that they can accommodate any bicycle that uses a quick-release mechanism on the back wheel. Most trainers come with a replacement quick-release skewer that can be swapped out with the original skewer to ensure a proper fit in the trainer. The quick-release cone and lever mechanism are inserted into holders on the trainer that keep the wheel firmly in place.
Left or Right?
Knobs on either side of the trainer allow for the wheel to be adjusted to either the left or right. This helps ensure the bicycle's rear wheel is centered on the resistance roller. Another knob on the roller itself increases or decreases the resistance as necessary.
Some bicycle trainers are emerging that give a truer riding experience. While many trainers simply act as stationary bicycles, newer designs are incorporating unique mechanics that allow for lateral movement. This trainer will actually lean from side to side to more realistically simulate the actual movement of cycling, particularly when stand-pedaling.
Year Round Riding
The obvious advantage to a bicycle trainer is that it can be used regardless of weather conditions or time of day. The same training regimens for road training in the summer can also be maintained on a trainer in the dead of winter. Additionally, trainers allow riders to work on specific weaknesses without concern about terrain or riding conditions.
No matter how convenient a bicycle trainer may be and no matter how hard the designers try, nothing can replicate the actual effect of riding on the road. Changes in terrain and road conditions are, in fact, an essential part of the riding experience and add a dimension that a trainer can't simulate.
If your trainer didn't come with a wheel block for the front wheel, you can substitute a book or a piece of scrap lumber to provide the necessary elevation to level the bike.
Place a hand towel over the bicycle's top tube to keep sweat from corroding the finish.
You'll sweat more and overheat more easily on an indoor trainer, since you're not creating any wind flow over your body. Drink water throughout the training session, and place a fan in front of the bicycle to help keep you cool.