External Bearing Bottom Brackets - How long before the bearing need replacing

[psmiffy]

I was watching a thread about external bearing bottom brackets to try to get an idea of their longevity - how long do they last - did not seem to be that long from the posts - as a tourer it would seem that i would have to change them mid tour on all but very short tours

 

[smokeysmoo]

Hard to say as depends on many factors as I'm sure you appreciate, but a good several 1000 miles has been my general experience.

It is generally accepted that they don't last as long as the older style sealed BB cartridges, but then again they are a far bit easier and quicker to change when they are goosed.

 

[psmiffy]

Good few = ?

(I reckon on around 16k to 20k for a moderate quality conventional BB)

 

[smokeysmoo]

As I said, hard to say. TBH I've never actually monitored it and therefore just stuck my finger in the air to give you a free bump in the hope you might get a more accurate answer.

If mine get graunchy they get changed, if they don't they get ridden.

I have no idea when I last changed one as I don't keep track of such things, and TBH for what they cost I don't lose any sleep over it.

No doubt there are folk who document every turn of every nut and bolt they ever make, hopefully one of those will have the answer you want.

 

[ianrauk]

The Hope BB on my Spesh has done over 16k in all weathers and is running as smooth now as it was when first installed.

My old commute bike Spesh Secteur had a Tiagra BB and did over 21k in all weathers with no problems.

 

[PatrickPending]

My experience, well I've done 5000Km on my bike with an external Ultegra bottom bracket and no signs of any problems. It does seem that the facing on the bottom bracket of the frame can cause problems if they're not properly faced (ie parallel) - no such problems on my Burls Ti frame which has these bearings, so I expect another 5000Km at least.
On my commuter (I ride in all weathers) I get around 12000Km + out of a 'conventional' BB.

 

[Smurfy]

In my opinion the external bearing bottom bracket design is a step backwards. Isn't it the case that the alignment of the bearings depends on the accuracy and quality with which the bottom bracket shell has been faced-off? Non-parallel facing-off = bearings trashed in no time at all. Sealed units have the advantage here because the bearing alignment is set at the factory and remains the same after installation in a bottom bracket shell. The old-style non-sealed bottom brackets with two cups, bearings and a spindle also required accurate facing-off on the bottom bracket shell to ensure the bearings were running true.

 

[Cubist]

There is also a disparity between the quality of various makes. I only have experience of Shimano Hollowtech II . Received wisdom is that they are to be treated as a disposable/consumable item. I happily swap them when they give up, and have found that lifespan depends on being kept clean, safe from jetwashing or other water ingress, but most importantly that the bearing preload is set properly. Overtighten the preload cap and they last a few rides only (I managed to trash one of Cubester's by doing this).
You can pick them up off MTB site classifieds for less than fifteen quid, as many folk upgrade as soon as look at them, and I have a spare in my toolbox for the next time one goes tits-up.

Shimano aren't easily rebuilt with new bearings, and the above pricing means this is irrelevant under normal circumstances. If you're touring though, you cannot guarantee it the bearing will last more than a few thousand miles.

Aftermarket may be the answer. Hope stainless steel at c£70 make some sense, especially as you can get pretty colours, but they can be rebuilt. Their bearings can be changed without much fuss. Chris King at c£120 are superb but I would struggle ever to justify the cost.

There is however a middle ground. I've just ordered a Gusset Ext 24. Anodised red, replaceable bearings (which according to reviews are likely to last as long as Hope) and all for the princely sum of £21. No brainer.

 

[GrumpyGregry]

The SRAM GXP ones are made from cucumber ime.

 

[Svendo]

The SRAM GXP ones are made from cucumber ime.

+1 (although mine were truvativ branded, but basically the same.)

Also had poor experience with FSA Megaexo (although they have lots of slightly different ones so ymmv. Mine were for a steel energy chainset from a 2007 Focus.)

Currently have a Shimano DA HTII and it's been faultless for 12K+ miles. Thought it was getting lumpy a few times, but has turned out to be the pedals or cleats clicking/bumping or squeaking.

 

[Alien8]

I got about 8K-miles out of a Tiagra HTII before the drive side went. The non-drive side felt fine. Is that typical? No idea - but I would hope not.

 

[gbb]

+1 (although mine were truvativ branded, but basically the same.)

Also had poor experience with FSA Megaexo (although they have lots of slightly different ones so ymmv. Mine were for a steel energy chainset from a 2007 Focus.)

Currently have a Shimano DA HTII and it's been faultless for 12K+ miles. Thought it was getting lumpy a few times, but has turned out to be the pedals or cleats clicking/bumping or squeaking.

My experience, and plenty of others as well if you read the net, is the megaexo are poor. Bearings are base quality and shields collapse. I managed 1000 miles on mine before it went.
But then, you can't have quality at budget prices.

 

[Judderz]

Shimano 2300 internal BB on an Orbea lasted1800 (ish) miles before I replaced them, turning it by hand with the chainset off, you could feel the roughness.

Tiagra Hollowtech II - on a friends Giant, lasted about 2200miles, a 'clicking' developed whilst out on a ride, on inspection, the BB was goosed.

 

[Kestevan]

I find that the tiagra hollowtech BB on my commuter lasts about 12-18 months/3000 miles.

I tend to replace it every spring as its started to "click" and get rough/notchy after a winters hard use.

 

[MattHB]

My experience, and plenty of others as well if you read the net, is the megaexo are poor. Bearings are base quality and shields collapse. I managed 1000 miles on mine before it went.
But then, you can't have quality at budget prices.

+1 on this. I killed a megaexo set in 1200 miles. They were rubbish