I plan to pull my cranks and BB this weekend to try and fix a squeek. This makes me ask: How often, if ever, do you replace a BB? It seems to be working fine except for the squeek which I hope to resolve once I remove, lube and replace. Is replacing a BB a routine maintenance item? Thanks.
What kind of bottom bracket? With some of the modern bottom brackets you may just be able to swap out bearings when they wear out, others the whole unit will have to be replaced and others one can replace and repack the bearings.
I am talking about the newer sealed ones. Pull the old one out, stick the new one in. I imagine they eventually must give out and need to be replaced at some point. Just curious if people look at these as a routine maintenance issue and just replace them every once and awhile or do you just leave them alone along as they aren’t causing problems.
As long as you keep using grease to repack them, they will basically last forever. If something in it breaks, then it should be replaced.
The ones that come out in one piece will need to be replaced as water does get into and the grease does get used up or replaced with water/dirt. Depending upon how much you ride in rain perhaps taking it out once a year to see if it rotates freely and smoothly, maybe more if you ride a lot in the rain. You can check this a bit (but not as well) by taking the chain off the chainring and listening/feeling as you turn the crank by hand without removing the bottom bracket.
I’ll definitely take the opportunity to check the BB whenever I have the cranks off for any reason, whether swapping the cranks or just the rings (sometimes it’s easier to do on a workbench, especially a compact MTB triple where the inner ring blocks access to the backside of the middle ring nuts). Just give the spindle an easy spin with the thumb and index finger (assuming it’s an older square-taper or Octalink/ISIS; if it’s the newer external cup, you can kinda plug a finger into the inner race and rotate it)… You should be able to feel whether it still has that smooth, lubed feel or if it’s either scritchy or too loose. Your feel is much more sensitive that way; if you just spin with the cranks still on (chain off, of course), the rotational mass of the cranks may mask the resistance in the bearings and it’ll still spin OK unless the BB is really crunchy.
Replacement or not totally depends on the type of BB and how bad the problem is. Is it a common style/size? Some are worth taking apart to clean/re-grease or replace parts yourself; others are either not user-serviceable or not worth the trouble… just toss and buy a new one.
I really don’t know what type BB it is. The bike is a 2005 Specialized Allez Elite with Octalink cranks and triple chain rings. I can see “Shimano” stamped on the non-drive side of the BB. I am guessing it may be one of the sealed type of BB. All good ideas here. I do ride in the rain sometimes. I also live near the coast and salt air is common. Guess I’ll just have to dig into it and see what I find!
If its Octalink its most likely a sealed Shimano unit. They are pretty much a throwaway item. The Dura Ace version was rebuildable, but your bike wouldnt come with that version. Check the bearings for smoothness as others have said, and also check to see is there is any play in the bearings, you can do that by rocking the crank side to side.
Kevin
We have the exact same bike, yes the BB is Octalink. Mine worn out in about 2 years. You can check the BB by moving the crank sibe by side, hope this pic give you a better idea:
If you feel it a little loose, maybe the BB needs to be changed.
Any mechanic can help you with this.
Carlos, if the crank has play in it, then it’s the tension adjustment that’s a problem, not the bearings.
You can always adjust the tension with a ring on the non-drive side crank arm.
Regardless of the type of BB, once you get the cranks off give the BB a spin to see if its smooth, seized, gritty, etc… There should be a bit of resistance, if not then the grease is most likely non-existent in a traditional loose ball BB. If theres a gritty feeling or its hard to turn, we usually just replace the unit. They aren’t that expensive and the labor costs of trying to rebuild or clean thoroughly is higher than the cost of a new BB. When you reinstall, clean all the threads with alcohol and apply 2 drops of blue Loctite to the threads on each side, then torque to spec.
-Cory
That’s what the mechanic at a LBS told me and he sold me a new one, I think i got Pwned 
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That’s what the mechanic at a LBS told me and he sold me a new one, I think i got Pwned
Hey wait a minute…You were talking about OCTALINK bottom brackets, but your picture shows an integrated spindle crank.
If your crank is the one in the picture, then I think your LBS was wrong. If you have an Octalink BB (which uses a captured spindle inside the BB cups right?) then side play would be worthy of a new bottom bracket.
I used to think bottom brackets wore out quickly because every time I had my bike looked at by my LBS for what I thought was drive train noise, it came home with a new bottom bracket … though often still with the same noise when I rode it again. Now I have my own “wrenches” and find that I still have drive train noises at times, but I have virtually never needed to change a bottom bracket (Campy record). When I have my own ability to work it through, I have found cranks, pedals, chain, rear cluster, rear hub all to be far more common issues for drive train noise. I don’t worry about BBs unless the pedals don’t spin freely or there is obvious “play” laterally … which really seems to show me the BBs are pretty solid stuff. Checking the torque settings occasionally is important as even with locktite they can loosen minimally over many miles.
I’m not a pro wrench, but I would just say be suspicious when your BB is said to be a problem.
Dave
You should also spin the crankarm backwards and check for bottom bracket play in four arm positions: 12 o’clock, 3, 6, and 9 o’clock. It could be loose in one orientation and not in others. Not all bottom brackets can have play adjusted. On some, all you can do is change it.
The octalink is an older style cartridge bearing system. You can grab the crank by the pedal end and try wiggling it toward the midline, or if the cranks are off the bike just turn the springle with your fingers, it should feel smooth with a little bit of tension in the bearing. Some of the older Dura ace BB’s had a hole in them that allowed water to run down from the seat tube into the bearing shell, I had one fail after a spring season of racing in the rain.
On the bike, a bad bottom bracket starts klunking when you spin at high rpm’s in an easy gear.
If your is worn out, a new one will feel nice. Otherwise, you only need to replace it when it fails, not on a schedule.
UPDATE: My BB tool finally arrived and today I successfully removed, cleaned and reinstalled my Shimano Sealed BB. I was surprised at the amount of water that flowed out. I rode in the rain last weekend, that must have done it, but still wasn’t expecting the amount of water that was trapped in there. The BB seems o.k. though I can’t really tell. It doesn’t wobble and it spins smoothly, but certainly not as smooth at the wheels do. I may have to go to my LBS and spin a new BB for comparison. I guess I just expected it to spin easier than it does. Once everything was put back together, it seemed to ride fine on the trainer. No squeeks so far! Thanks to all who gave me great advice on how to remove both the cranks and the BB. Easier than I thought it would be.
UPDATE: My BB tool finally arrived and today I successfully removed, cleaned and reinstalled my Shimano Sealed BB. I was surprised at the amount of water that flowed out. I rode in the rain last weekend, that must have done it, but still wasn’t expecting the amount of water that was trapped in there. The BB seems o.k. though I can’t really tell. It doesn’t wobble and it spins smoothly, but certainly not as smooth at the wheels do. I may have to go to my LBS and spin a new BB for comparison. I guess I just expected it to spin easier than it does. Once everything was put back together, it seemed to ride fine on the trainer. No squeeks so far! Thanks to all who gave me great advice on how to remove both the cranks and the BB. Easier than I thought it would be.
?? what is there to clean?? If you ride in the rain, pull your seatpost after you wash your bike and store it upsoide down so it dries out.
I got by my LBS today and was able to spin a new BB to compare with mine. My BB is fine and doesn’t need replacing. My LBS gave me the same advice about removing the seat post and hanging my bike upside down after riding in the rain. Thanks. I rode 26 miles yesterday and the cranks and BB felt great. No creaking!!