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Previous posts describe how to add grease to the large Flywheel Bearings in the SB20.  This post shows how to replace them. I used 6910ZZ bearings that cost less than $15 each.   See the FAQ below for a discussion on using name brand versus generic bearings . Video Here's the video. __________ Flywheel Bearing Removal Steps Replacing Flywheel Bearings  requires the following steps: Perform Flywheel disassembly as described in SB20 - Advanced Flywheel Servicing .   Remove Coils and Optical Sensor . Remove and replace large Flywheel Bearings . Replace Coils and Optical Sensor . Perform Flywheel re-sassembly as described in SB20 - Advanced Flywheel Servicing .   Difficulty Level Servicing the  Flywheel   bearings requires some advanced DIY skills. I rate the difficulty to be  9 out of 10 . While nothing is technically extreme, I rate this harder than similar tasks for the following reasons: Risk of damaging the Stator - particularly t...

Making Your SB20 Flywheel Easier to Service When replacing or servicing the Stages SB20 Flywheel Bearings , a few questions are commonly asked: Loctite adhesive is recommended to glue bearings in place. Where should it be used?  Can you over do it?  Can you skip the Loctite? Reassembling the drive-side axle can be difficult. There is not enough room to insert a cone wrench to properly tighten the flange and lock nuts. This means the flange nut can come loose allowing the entire flywheel to potentially move.  What can you do ? Video Here's the video. This post expands on my previous  Flywheel Servicing posts and videos: SB20 - Advanced Flywheel Bearing Servicing SB20 - Flywheel Cog and Axle Bearing Service Stages SB20 - Drive Belt Adjustments (2025) _____________________ SB20 Flywheel Bearing Design The design of SB20 flywheel relies on some basic principles: The axle and flywheel bearings expect an  interference fit  on their outer rings . The means the ...

This post focuses on disassembling the SB20 flywheel to extract the internal electromagnet stator assembly from the flywheel shell.    You can then add grease to the large Flywheel Bearings or replace them. You can also replace the Optical Sensor should you need to. Video Here's the video. Who Should Do this Service? Anyone who wants to extend their flywheel life . Sealed bearings can last a lifetime without servicing - but they can also fail after a few years. One way to maximize lifespan is to add grease once or twice a decade . If you have grinding, clicking and thudding sounds that indicate bearing failure. All SB20 flywheel bearings are inexpensive. The service procedure shown can also be used to replace bearings. You read the Stages service bulletin on quieting clicking flywheel noises , and want to do a better job. In short, servicing sealed bearings is optional. Most bearings never fail. Extreme temperatures, and exposure to humidity can be a negative factor. Ju...