how often(in miles) do you have to replace your BB?
 

Just wondering what is the average life for different brands model. Obviously it depends on the model too.

Personally I am comparing Sram rival GXP and shimano ultegra external bb. Seems like the Sram one wears out faster?

Had to get a new spindle and bearing balls after about 60 kmiles for my Shimano 600 (now called Ultegra) BB when the original ball cage disintegrated. It has now gone another 60 kmiles without any more problems. My experience has been that BB failures are rare enough that it's not very meaningful to assign a life to them in terms of miles.

Well I had to replace by bb30 after several months because of bad bearings. I have 2 bikes from 93 and 94 with untold miles and the bbs are still spinning like the dickens.

bb30 headaches.

glad they make an adapter.

I have an older 7400 bb, obtained from southland corporation. It has 250000km on it. And those are mine.

Yes.

You have 150,000 miles on one bike, or have you switched the bb to different frames?

Varies. High-quality square taper or octalink BBs with internal bearings lasted almost indefinitely. I have about 15k miles on my 5500 BB and it's totally fine. OTOH crappy internal BBs (some ISIS models) would let go after only a few thousand. External BBs, from what I've seen here, tend to last less, especially when used in poor weather. Fortunately they are pretty cheap to replace.

Replaced GPX after 20K miles only becuase me was overhauling the entire drivetrain at the time... again; the replaced is now #1 spare

The mtn GPX was replaced after less than10K miles because it'd become a box of rocks; weather and exposure kill'd it.

line it up, keep it dry - nearly forever.

Great, I always thought shimano makes good durable stuff.

this: on http://www.mtbr.com/cat/drivetrain/b...65_104crx.aspx their bb get pretty bad reviews. Seems like they break down more frequently. Granted this might not matter to me much since I am a fair weather road cyclist?

More info on travativ gxp please.

From a durability stand point, is the older models of BB better than external BBs? Does truvativ GXP and/or shimano part of the "ISIS" model speak of?

I just read online that GXP develops a creaking noise and need replaced after <= 5000 miles..

It has been on three of my frames. Southland, btw ran the 7-11 team.