Repeat rusting out of BB bearings

My BB was making awful sounds again…about 6 months after replacing the steel bearings. Once again, the bearings are rusted and the LBS tech can’t get a delivery date for Trek replacement bearings. He thinks ceramic bearings might be a better option. I’m sure it’s due to indoor training but I’m not sure what more I can do to prevent this. I have towels as close to the crank as I can and loads of air movement. Anyone else having the same issues or know how to prevent this? Thanks

Try using either Hawk Stainless Steel (FSS plus CXSeal) or Enduro 440C bottom brackets.

Those are two good options for bottom bracket longevity in wet/goopy conditions. Ceramic bearings are almost never a better option on a bike. I think you’ll be happier with a stainless steel option that has robust seals.

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There should be some seals in there.

I have over 20000 miles on my BB, and that thing has been fully submerged while riding though a flooded area multiple times on my commute, besides all the rain riding, dripping water bottles, etc.

most ceramic bearings still have steel races so it might not fix the issue. Have you tried slathering the area with a marine grease? If the seals are completely covered water is unlikely to make it in there. If you have a lot of sweat dripping you might want to consider additional cooling as well

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I don’t think ceramic is a good option either but Trek has “no delivery date” for their proprietary steel bearings and my LBS said nothing else will fit. Tough to have my bike out indefinitely.

I will try this. I’m very surprised anything can get in. I’ve had one fan purposefully blowing my vapours directly away from the BB. It’s odd that it’s not better sealed.

Can you check the markings on the bearing seals? AFAIK they are just 24x37 bearings, which Enduro makes. Those, coincidentally, are the bearings used in many 3rd party bottom brackets, for Shimano cranks. Such as BSA bottom brackets from WheelsMfg, Rotor, etc.

The fan should be on YOU, not on your BB.

Hambini has great customer service and can recommend and sell you bearings that will work in your situation. As well as inform of any tools needed to do the work, if you don’t already have what you need. If not familiar, you’ll love or hate his youtube channel. He’s polarizing as a public persona. Via email, he’s entirely helpful and professional, and remarkably prompt. If you get a multitude of answers on this forum, he is who I would contact via his website.

This. Keeping your body cooler will mean less sweat that can drip down in the first place. This is where I would start.

Regarding the bearings, if you’re only using the bike indoors, it should be fine to clean them and re-pack with grease, until the new bearings arrive. I’m not convinved only Trek’s bearings will fit - pretty sure they don’t make their own, so they’ll be buying them in from somewhere. If you can’t read the number on them, measure them.

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