Bicycle Mechanics - Bottom Bracket Longevity/Suggestions?

I have about 4,000 miles on both an Ultegra BB and chain (they are both the original for the bike). The problem: The BB now has a slight bit of play (definitely the BB, not the cranks), the chain is clean, tight and 12 links are exactly 12". I obviously have to replace the BB (the amount of play is just getting worse each week) and my question is why? How could a chain outlast a BB? Is there any way to prolong the life of a cartridge BB? Everything is sealed, why would it wear faster than an exposed chain?

What are your experiences for this brand/model of BB; how long does yours last? Are there any recommendations to get better longevity (i.e. better models, different types)? I understand that bikes DO occasionally require money, but I like and seek durability. I am just baffled how a measly chain could outlast a sealed, cartridge BB.

It is called the disposable society.

Some things are better left unanswered. The knowledge may not truely enlighten us.

I think your riding style has a lot to do with. I am a grinder with 175’s and big gears, I replace my BB almost every year. Some of the people I ride with that are spinners get many more miles from them. If you stand with big gears you will stress the BB more. But I also usually trash my chain.
Also like was said before they are not meant to last. It is all about the money.

I replaced my Sora BB at about 3000km...... chain is still fine. I used to mash alot (150pounds) and stuff but I now spin. I replaced with a BB UN73 - so far no problems. Chain might be next to go......

Brendon
:beer:

Somethig is definately up.

If you have 4k on a chain with no stretch you are doing alot better than me.

As far as the bb, do you clean your chain on your bike alot? Sometimes the degreaser leaks into the bb, and this reduces the life span. Even though they are sealed, I think we all know they are not bomb proof.

Submersion or rain rides over time have the same effect.

I do clean/lube my chain often, while it's on the bike, but I'm not very liberal with the degreaser and I don't believe I've caught the BB with it - but who knows? I also ride in the rain (it IS Oregon after all), so maybe that contributes. But, again, I still would expect the chain to succumb first, given its exposure.

So, I guess my maintenance efforts are certainly saving my chain, but my non-servicable BB is toast. Hmmmmm, whatever happened to those days where everything was maintained? I wonder how many miles I could crank out then?

I've heard people say the ultegra BB is prone to wearing out faster than 105's or "lesser" quality BB's.
I've had good luck with UN-72's so far.
I am a spinner and rarely push big gears for long; that as mentioned above could be a factor.

Chances are you will have better luck with the next BB.

I do clean/lube my chain often, while it's on the bike, but I'm not very liberal with the degreaser and I don't believe I've caught the BB with it - but who knows? I also ride in the rain (it IS Oregon after all), so maybe that contributes. But, again, I still would expect the chain to succumb first, given its exposure.

The thing is you relube your chain after a cleaning. The bb just gets flushed with degreaser and does not get relubed. The rain rides then clean the lube and degreaser out.

I am not for sure this is the problem, it is just the only thing I can think of.

This is why I like the Dura ace or any other adjusteable not sealed bb. They don't stay clean as long but you can aclean and relube them. It takes a little more effort but it will last longer.

Yup, captsven, I agree. Wish we could bring back the old ones. Replacing a cup or a spindle when needed was easy and cheap.

Another step backward for the sake of convenience.

OK, now we're gettin' somewhere. I've read reviews claiming that a Dura Ace BB isn't as durable as Ultegra, but you are saying they're adjustable? Are they just not durable because people don't maintain them? I am more than willing to do the work if it will last.

All the "old type" BB's were adjustable and serviceable. The BB's available now(including Dura Ace) are all cartridge type; screw 'em in and ride. Nothing wrong with that until they need serviced; that's when you throw 'em away and buy new ones.
They are not durable because people CANT maintain them. :-(

Rev. Chuck or any of the other bike shop guys here can probably tell you if it's possible to find any NOS (new old stock).

The current Dura Ace bb is NOT a cartridge type. Does Shimonster advertise this as a disposible cartridge bb?

You can remove the bearings (they have both ball and roller) clean and relube them. You also need to adjust them like a cup and cone when you install it.

I do not know for sure but I would think that with proper cleaning they will last longer than a sealed type. You can not easily (at least to my knowledge) relube a sealed cartridge bb.


dura ace bb (http://bike.shimano.com/product_images/BB/si_images/BB-7700-BB7703.pdf)


ultegra bb (http://bike.shimano.com/product_images/BB/si_images/BB_6500_SI.pdf)

Originally posted by Greg
Some things are better left unanswered. The knowledge may not truely enlighten us.

If there is play in a bottom bracket in a forest and no one is listening - does it make a creak? :)

I used to use adjustable BB's and were fine. Big problem was that they used to pit, but that was because of Scottish winters, and ajustment was an art.

I'm now using a Stronglight sealed BB and it has 4000 miles plus on it and is fine. The ShimaNO sealed one before it gave up the ghost early on.