When pedaling, the flywheel makes noise.


There are some noises the flywheel may make that are normal, however most noises that could come from the flywheel are abnormal and should be checked in the sections below.

Before troubleshooting

Some noise is normal. Read the points below before continuing to the troubleshooting section:

  • The flywheel may make a light beeping noise that is most notable when pedaling very slowly or coasting - this is the control system frequency and is normal - there are no additional steps to take. This noise should be faint and difficult or impossible to hear when pedaling the bike normally.
  • There may be a faint or somewhat loud "tick" that occurs once per flywheel revolution, it is likely this noise will go away with some use and is not an issue to the functionality of the bike unless your bike reports no cadence, feel free to contact support about this noise but there is no need to continue further.
  • When coasting there may be a light freehub-like clicking, similar to coasting on a normal bike, this is the freehub bearing and, unless bothersome, is to be expected and not reason for concern.

Loud banging, scratching, "rock tumbler," knocking, or other abnormal noise should be addressed in the following Troubleshooting section.


We have noticed a small number of flywheels making various noises - each has its own set of troubleshooting steps, organized by noise type below:

Grinding accompanied by difficult pedaling

If the bike is easy to pedal in reverse, skip this section and move on to the next one.

If there is resistance to pedaling the bike in reverse, it's possible the belt tensioner is loose or not attached. If this is the case, create a new support ticket. There is a potential simple fix to this issue included in the next steps that you may want to try, which will also give our support team a better idea of the issue and help to resolve it quickly.

Repair guide

  1. Remove the front right flywheel cover by removing the two (2) 3 mm bolts, as shown below:
  2. Pull this cover away from the bike and then rotate it to remove it from the two posts connected to the right leg:
  3. Check to see whether the part indicated below is present, and if so, whether it is tight against the frame by trying to wiggle it - it should not be easy to wiggle:
  4. If this part is missing, falls out when you remove the nose cone, or loose, your noise issue is likely caused by this. This part keeps tension on the belt so the crank and flywheel turn in unison. Stages can send a technician out to repair this, or you can do so yourself if the nut and metal bracket can be found. Move onto the next step to repair on your own or contact our support team by submitting a new ticket.
  5. Tighten the bracket and nut against the frame slightly using a 7 mm wrench.
  6. Loosen the 14 mm nut on the flywheel axle (pictured below) so the flywheel can slide forward:
  7. Tighten the 7 mm nut one full turn and pedal the bike. A loose belt will have a slack feeling when pedaling from stationary, and a too tight belt will make a lot of ambient noise when pedaling hard. Adjust this nut and check the feel of the bike until you are satisfied.
  8. Tighten the 14 mm axle nut.
  9. Replace the plastic cover.

Scratching, grinding, or banging in rhythm with the flywheel speed

If the flywheel makes a very similar sound with every revolution, it's likely that the flywheel is rubbing against the belt cover here:     

To check if this is the problem:

  1. Pedal the bike so the flywheel is spinning and making the noise.
  2. Get off the bike to the left side and hold the pedal with your right hand to keep it from spinning.
  3. Push on the Stages logo on the belt guard:
  4. If the noise stops as you push, follow the steps in the next section to repair the issue.

Repair guide

You can create a ticket to have this issue resolved by a technician or follow the simple steps below to fix this issue yourself:

  1. Remove the two (2) 3 mm bolts from the front right flywheel cover.
  2. Check that the two screws indicated in the picture below are holding the belt guard to the right leg. We have seen an issue where these screws are actually not holding this belt guard to the leg, and instead pushing the belt guard into the flywheel.
  3. Remove and reinstall these screws so the belt guard is no longer being pushed into the flywheel.

Random rock tumbler noise, or seemingly random or sporadic knocking, clicking, or banging.

If noise continues, remove the rider left-side flywheel covers to ensure that the Stator Bolts are tightened. NOTE: Unplug the bike prior to removal of covers, for your safety and these covers protect vital electronics. 

Repair guide

  1. Remove the two (3 mm) screws from the left front plastic flywheel cap.
  2. Remove the two (3 mm) screws on the left rear plastic flywheel cap and remove the cap; set aside for reassembly later.
  3. Once visible, verify the two stator stay bolts (5 mm) are tight. The stator set screw above the bracket (6 mm) needs to be verified for tightness as well. 
  4.  After verifying tightness, re-install both flywheel covers. 

If these fixes do not resolve the issue, and you have ruled out all cases in the Before troubleshooting section, it is likely your flywheel needs a replacement. Submit a new support ticket to schedule a replacement and technician.