Do bottom bracket cups wear out?

[Rhys W]

I'll be replacing the chainset of my best bike soon - Chorus Ultra Torque, Italian threaded BB shell. The cups were installed when I bought the bike about 6 years ago. Is it worth replacing the cups, or just taking them out, cleaning the threads if required and reinstalling?

I've read some stuff that it's counter-productive to take old ones out and re-installing them for no reason, especially if the shop did a good job in the first place (they did). With internal BBs I think it might have been a good idea to take them out every now and again just to check, but it doesn't seem to be necessary with external bearings, as there's nothing there really to wear out.

[trekker12]

Yes they do wear out - well the bearings inside them can wear out.

Riding into work on my winter bike last Friday (having been used throughout a pretty dirty winter and lots of road spray all over it) I notice some play in the pedals which had got noticeably worse by the time I got to the office (well my paranoia was probably worsening). There was a visible gap between the crank and the BB cup and I could move the crank about 1mm in/out. It only took 20 minutes yesterday afternoon to take the old cups out, clean everything and fit new ones.

It's up to you if you want to replace the BB with the new chainset. Not sure I'd worry too much. It's not a complicated job if you do want to change at a later date.

[Veloman]

Having used Campag external cups for may years, my advice would be to install new ones, particularly as the cost is not really significant when compared to the cost of the Chorus c/s.

I also surprised the bearings have lasted so well after 6 years.  I have move from Campag c/s to Shimano for my audax bike as the external bearings were so exposed that extended use during poor weather the bearings did not fare very well.  I still use Campag for everything else and find no problems using a Shimano c/s with everything else being Campag.  Bearing life so much better for Shimano based on my experience.

Also interesting to note that Campag do not offer PT in the more expensive c/s and stick to UT.  Having wore the splines on a PT c/s, I can understand why!

[yoav]

Sometimes they can fail catastrophically. I was out with my son on his Shimano equipped bike when the cranks appeared to seize up - he couldn't turn the pedals at all. Fortunately we were close to home and further inspection revealed that one of the external bearings had collapsed. One new set of bearings later and all was well.

[Rhys W]

I am on my second set of bearings, and this bike only goes out April-September anyway.

I'll probably take it into the shop that fitted them in the first place and ask their advice.

[Rhys W]

Looks like my decision has been made for me. I removed the cranks and the LH bearing is stuck in the cup. 

[Veloman]

Looks like my decision has been made for me. I removed the cranks and the LH bearing is stuck in the cup. 

Good old Campag design with poor bearing protection as suggested in my previous post!

[interested]

Good old Campag design with poor bearing protection as suggested in my previous post!

My Campag UT cranks (Centaur 2007) came with bearings that was only shielded on one side. I think that since the UT cranks are so easy* to take off, you are meant to replenish the grease inside at regular intervals. That way you can hose down the bike after a ride without destroying the crank bearings. Probably a nice feature for Pro teams or people that like to keep their bike very clean. I fit neither category, but I actually like to be able to service my crank bearings by re-greasing them.

*well, for certain values of easy.

[Veloman]

I am an out and out Campag chap, but I can use Shimano c/s with my Campag kit and hose the bike regularly without having to service the bearings by re-greasing.  just seems Shimano has got it more right than Campag so far as the bearings are concerned.

[Hot Flatus]

Agreed.  The Campag BB system is a pain with no discernable advantage.

[frankly frankie]

just seems Shimano has got it more right than Campag so far as the bearings are concerned.

Do Shimano do Italian BB ?   If not, I expect Hope do.

[Veloman]

Do Shimano do Italian BB ?   If not, I expect Hope do.

Yes, and an example:

http://www.ribblecycles.co.uk/sp/road-track-bike/bottom-brackets-bottom-brackets-shimano-105-5700-bb-cups-105-10-double-triple/shimbtbr720

[Rhys W]

Agreed.  The Campag BB system is a pain with no discernable advantage.

I have finally come round to your way of thinking.

Been having a bit of a nightmare installing my new chainset. The two half-axles wouldn't line up and mate so I had to take them out again. They left the damn cartridge bearings in the cups again, despite the little spring clip that's supposed to to hold them onto the axles. One eventually came out but the other is stuck in at an angle. I've never been convinced by press-fit things engineering wise.

I'm going to have to let some professionals sort it out for me now. I watched the youtube videos and it looks so easy, just press them in from either side with gentle hand pressure. In my spares box I found a Chorus cartridge BB with square axles, which you installed in the shell using a cassette lockring tool, then just tightened the crank bolts. The bearings were inside the frame, hidden from gritty spray. Why oh why did they change that?

[rafletcher]

They left the damn cartridge bearings in the cups again, despite the little spring clip that's supposed to to hold them onto the axles. One eventually came out but the other is stuck in at an angle. I've never been convinced by press-fit things engineering wise.

On a small point of engineering - if a clip is deemed necessary to hold the bearing on the axle for removal purposes, it (the bearing) won't be a press (interference) fit in the housing/cup. If it were (like the bearings on my BB86 BB) they'd (be meant to) stay in the cups.  Get them in at an angle, and yes they can jam. I assume the design is such that you can't get a drift (screwdriver blade) behind the bearing from the back side to knock it out?

[Rhys W]

Well, the answer to my original question is: Yes. Yes they do.

The guys at the bike shop thought the reason I had problems with the bearings not seating properly was some of the plating had flaked off the cups, there was therefore a minute variation in diameter enough to persuade the bearings to not go in square.

Remarkably, they had a pair of Campagnolo Italian thread cups in stock (they only keep one set of those in stock!) and fixed it for me on the spot. Brilliant service as usual from Cyclopaedia in Cardiff.