What are the different resistances on exercise bikes?

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Rob, check the links.
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Interfaces to exercise bikes are different between manufacturer and model. If the bike worked before this way then I would recommend removing the power from the bike for a few minutes and then plug it back in. This will reset the computer. If this does not solve the problem then you should contact the manufacturer.

If this is a new bike that may be the way it is. If it worked differently in the past, you may be looking at a busted tension motor or faulty brake.

Have you updated the software? Have you contacted the manufacturyouer? It may need a software update. Without knowing the make and model it is difficult to direct you for a fix. If you have a manual, look at the trouble shooting section.

In most exercise bikes, you can control the resistance and the time. You can choose the resistance level and the duration of the workout.

Without a doubt, the most popular form of resistance used in exercise bikes is magnetic.

The new and improved exercise bikes have what is called magnetic resistance. This is where your resitance is created by a magnet and some sort of power source such as batteries or your bike being plugged into a wall outlet. If you are using batteries replace them. I found that with my elyptical exerciser new batteries made a world of difference in the resistance settings. Make sure the batteries are strong ones. If changing the batteries doesn't help then there may be another problem. This could be the computer or a magnetic part. These parts are usually replaceable through the manufacturer. Just check your user manual and I am sure you can get it replaced. I hope this has been helpful.

If you are refering to a regular bicycle this means the derailer is not making the chain jump from gear to gear. You probably need a new shifter cable or the shifter cable came unhooked from the derailer. I would take your bike to a bike shop to have this reconnected and then they will adjust it for you.

If you are refering to an exercise bike then here may be your solution. From what I have seen on exercise bikes there are three different kind of bikes. I am refering to how there resistance works.

First type has a strap that wraps around the wheel. There is a some kind of a nut and a bolt that holds that strap around the wheel. You simply need to tighten that nut. The strap will stretch over time and that is why you do not have the same resisteace you had when the bike was new. Afer you tighten this you will find that regular tensioner works better.

The Second type of exercise bike has what appears to be brake pads contacting the wheel. Basically your peddaling the bike with the brakes on. Pretty simple concept. Again there should be some sort of adjustment around this pad that is touching the wheel. Probably a screw or a bolt. Some even have adjusters that you can turn with your fingers.

The new and improved exercise bikes have what is called magnetic resistance. This is where your resitance is created by a magnet and some sort of power source such as batteries or your bike being plugged into a wall outlet. If you are using batteries replace them. I found that with my elyptical exerciser new batteries made a world of difference in the resistance settings. If changing the batteries doesn't help then there may be another problem. This could be the computer. Just check your user manual and I am sure you can get it replaced.