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Repacking Cartridge Bearings

Not long after a recent bike wash I noticed a pedaling-related squeak when riding my Mukluk. I figured it to just be some seal noise, so after today’s wash I removed the cranks and set about investigating the snap-on seals that came with the crankset, figuring it to be one of those. Instead it turns out that the noise was coming from the non-drive side cartridge bearing, which was also feeling a bit rough.

I had two spare bearings from the last time I needed to do bearing work, so I figured I’d try and salvage these. Pulling the seals off I found that they had a bit of creamy (likely water-spoiled) grease inside, but seemed to be in otherwise good shape. I removed the grease and found them to be spinning very smoothly when clean, so I lubed them up with some ProGold EPX Cycling Grease. This is a nice, sticky grease that seems like it’d be good for bearings in harsher environments. (Disclaimer: I received a free tube of this as part of the large set of stuff donated to MMBA Metro North / CRAMBA in 2011.)

Everything went back together nicely, and now the cranks spin smoothly without any irritating squeak. I hope that this new grease will be a bit more weather resistant than whatever came in the eBay special bearings I’d purchased and these bearings will last for a while. They were nice and clean and spinning smooth once cleaned out, so I’m hoping I caught them before any damage was done.

Here is the general process I used for cleaning the bearings:

  1. Use a sharp T pin to carefully remove the seals from the bearings.
  2. Wipe out as much grease as possible with a paper towel.
  3. Soak the bearings in citrus-based degreaser. (I use ZEP, it works just as well as the bike specific stuff.)
  4. Alternate between rinsing the bearings in hot water, brushing them with a degreaser-soaked toothbrush, and swirling them around in the degreaser bath until they are clean.
  5. Once the bearings are very clean, rinse in as hot of water as possible, then shake dry.
  6. Blow dry with a blower or air compressor, if available.
  7. Submerge the bearings in 99% isopropyl alcohol and agitate to get any residual water off of the bearings and dissolved in the alcohol.
  8. Remove the bearings from the alcohol, shake them out, and set them upright to dry. Occasionally spin the bearings to help the process along. (This will only take a few minutes.)
  9. Liberally apply grease into the ball bearings and cage, then spin the bearing a few times to ensure it’s moving freely and grease is evenly distributed.
  10. Lightly grease the seals then snap them back in place with finger pressure. Spin the bearings a few more times to ensure the seals are properly seated.
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