Bit of rust in the BB Shell

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SolemnWeasel

Regular
Location
Edinburgh
More of a question 'how bad is it?' I took off the bottom bracket since it was creaking and I had a spare. Hollowtech BBR60 from Shimano.
Was not extremely difficult to take off, but had to use a hammer.
It does look quite rusty - the bracked was also cracked a bit around the thin edges, otherwise not so bad, but will not reuse. It was probably more than 10y old.
I cleaned the area with alcohol, wiped it with rags, and used a rust converter for around 15minutes (per manual) - then wiped it again and installed the new bottom bracket with some threadlocker. Plus I put grease where I could.
Hope that's enough - I need the bike so did not want to do more work on it.
I notice there is no pinhole on the bottom on the bracket.
Thanks

PXL_20250324_192426574.jpg


PXL_20250324_192357863.jpg
 

twentysix by twentyfive

Clinging on tightly
Location
Over the Hill
Surface stuff so not a worry. Just give a load of grease to prevent in future.

Where is the damp getting in?
 

Profpointy

Legendary Member
I'd not worry unduly, as, like txt says, it looks like surface rust. Might give it a good scrub with wire wool, and as you say, grease it up afterwards

Maybe drill a little hole in the bottom to let any condensation out, unless anyone can give a good reason why not
 

si_c

Guru
Location
Wirral
Pretty common with steel bikes, surface rust.

I'd clean the threads out and the inner BB shell with a wire brush, this will help keep the BB serviceable. Then use a rust inhibitor on the inside of the frame to limit rust build up and probably some lithium grease or water resistant marine grease on the threads of the BB when fitting.

You could drill out a hole at the bottom of the shell to help it breathe and eliminate any water that gets in but regular servicing should prevent any problems anyway. Just take the BB out of the frame a couple of times a year and give it a good clean.
 
Thanks. Not sure if there is water getting in - maybe humidity?, it was on the bike since it was new I think. I think the new bb and the shell is well protected now.

Water gets in past the seatpost as it is not an engineered fit in the tube and there is always a slight gap. Also through the slot where the clamp goes. The way round it is to cover both areas with some waterproof silicone sealant, use clear and it doesn't show.
 

midlife

Guru
I have a frame (653) that has 3 drain slots in the bottom but the most extreme I've seen is the bottom bracket that @midlife uses as his avatar

Lighter = faster :smile:. Probably picked up a second or two on my 25 milers BITD. :smile:.
 
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