edotomato

My bikes been through some pretty grimy road conditions these past few months, and after stripping it, the BB was a bit gritty. I gave it a surface clean (I haven't removed it as I don't have a BB wrench) and it improved to a slightly sluggish feel, but not gritty. Would it be a good move to drip so oil into it?

rpenmanparker 

The only way to lubricate a cartridge BB is to unseal the bearings. Some folks talk about doing that, but I wouldn't. I would just replace it. What I don't understand is what you mean by stripping it, but not being able to remove it because of no BB tool. What does stripping it mean? Are we talking about a three-piece crank with a sealed cartridge BB as the middle piece, or an outboard bearing BB and a two-piece crank?

JerrySTL

IMHO it would be a good time to replace it if it soon feels gritty again. Oil and grease don't mix all that well. Dripping oil into it could wash away the grease. You'd need to reapply oil frequently once you started using the oil.

Looigi

I pull the outer seal off the bearing and clean and add grease as appropriate, then replace the seal. It's easy. Usually, I preemptively add grease, as many BB bearings have minimal grease to begin with. The added grease helps exclude water and grit.

Most press-fit BBs are bad in that they tend to funnel water and grit right to the inner edge of the outer seal and then work it through the lip of the seal into the bearing as the crank turns.

edotomato

Sorry for the confusion, I meant stripped the bike. It's a 3 piece with a sealed cartridge.

edotomato

This was what I feared.

edotomato

Is this possible with out first removing the BB from the bike? I'll have little inspect in a moment.

rpenmanparker 

On the three piece type you only have to remove both arms and the non-drive side cup. The arms often come off with just an 8 mm Allen wrench due to having a self extracting bolt. Sometimes take off the adjustable cup with a pin spanner. Then the sealed spindle/bearings just pull out in one piece. Otherwise you need a crank arm remover. But in any case you don't have to remove the fixed cup. If you are lucky to have that setup and have those tools, it is easy.

Leebo

Cartridge BB's are a wear item. How old is it/ how many miles on it?

fietsbob

UN shimano type bbs are disposable, and priced low.

Looigi

Indeed, and they wear less and last a lot longer with added grease. Bonus: Adding grease is easier, quicker and cheaper than replacing them.

As mentioned, they can easily be serviced in situ.

lopek77

Just replace it. I use 3 different types of bottom brackets. I take everything apart to clean and grease the same day I hear first strange sounds coming from it. That include cleaning frame treads very well. Shimano BB can last a very long time. Sometimes is just luck, and sometimes is just maintaining it and keeping everything clean and dry. Expect 2000 or even more k happy miles from it. My bikes saw anything from salt water, sand, mud and everything in between. I "abuse" my bikes, and I love cheaper /they are not necessary low quality/ components. Easy and cheap to replace. My cycling fun never was and never will be spoiled by fear of braking/damaging my "high end", expensive components.

HillRider

How? With the exception of the Dura Ace version of the Octalink bb, all of the sealed cartridges I've seen are truly sealed and unserviceable without a can opener.

Leebo

As said before, they wear out. My last shimano un 54 had about 3 mm of play on the drive side. I just put in a new one for about $ 28.00. YRMV.

fietsbob

IDK if you can pop off the seal discs and add grease ..
or have a type of BB that uses a replaceable pair of bearings.

cny-bikeman

I would purchase a new unit and if practical add some grease to discourage reoccurrence of the problem on the new unit.

edotomato

Pull off outer seal: easy.
Add grease: easy- moving smooth once again!
Replace seal: yeah, there's no way that seal is going back in.