Ensure that your Spinning bike changes difficulty or intensity settings with ease. If the "gears" stick or you cannot change intensity at all, you probably have a problem with the cable controlling it. There are a number of different mechanisms for controlling intensity, but cable-driven systems are more likely to have trouble than crank down systems. Follow the manufacturer's instructions to repair a cable problem by replacing it.
Clean the resistance or intensity mechanism if you have a twist down setup that sticks or is otherwise non-functional. With a little cleaning and lubrication, you can get your Spinning bike changing intensity with ease. Again, follow the manufacturer's repair instructions.
Replace the hub if you have a wobbling resistance wheel. This problem can be caused by someone banging into the Spinning bike while moving it, bending the hub. Remove the wheel by loosening the resistance mechanism and removing the hub bolt. Sometimes you can simply replace the bolt to repair this problem.
Repair a rough drivetrain by keeping the chain clean. A dirty or unlubricated chain makes a lot of noise, feels as if there is sand in the chain and is difficult to ride. Run the chain through a rotating brush chain cleaning tool such as the one offered by Spin Doctor (see Resources).
Diagnose worn out pedals on your Spinning bike by checking for an angle other than 90 degrees to the crankarm, or by feeling a bump in the pedal stroke. Use a pedal wrench to remove the old pedals and replace them with new ones.
Fix setup problems by keeping your Spinning bike clean. If your handlebar or seat assembly don't stay where they're set, remove the components and clean them thoroughly inside and out, including the tubes. Run fine-grit sandpaper lightly over the mating surfaces to improve the grip.