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The question is how long does your last?
Reason behind my question is, that last September I replaced my Shimano XT HT2 bottom bracket with another Shimano XT replacement. The first one lasted 3 years before needing to be replaced.
I have to say that I have done over double the amount of riding over the last year and also now have Woburn as my local trails. Do I just take it that it has been a very wet year and now riding in a sand pit, has made it last only a year.
In my experience, the most common reason for BB failure is too much-pre-load while fitting.
Definitely a 'how long is a piece of string question'
So many variables it is impossible to be accurate assessing how long a BB wil last. On one bike an XTR has lasted 2 years and is going strong while the deore it replaced lasted 6 months. On the other bike an XT has lasted 3 years , still fine. However you are going to get people posting who can't make an XTR last very long and insist on buying more expensive BBs. Impossible to call
What druidh said.I killed one in 3 rides from over tightening. 😳
Now I`m very careful they last a year or more,but water in the seals kills them so try to avoid pointing a hose near it,and try to dry it out if you get it wet.
I have removed the top hat seals from dead ones and you can see how corroded the bearings get from water ingress.
I have eked out a bit of extra life by removing the top hat seal,cleaning,repacking with grease and re-assembling but it is a short lived cure before they get really grumbly.
my last one lasted 3 years of regular riding, and it was 2nd hand to me.
The last one I had lasted a year (Saint), but the prior one (another Saint) lasted a good couple of years.
As above, it's a piece of string question, but I think the last one got battered due to being ridden more/harder so didn't last as long as the one before.
IME Shimano BBs are pretty durable, RaceFace bbs on the other hand... 😉
I mangled a Deore one in I think 3 days on the DH bike 😳 Bearings damaged rather than seized, hadn't seen that before.
SLX/XT in all the other bikes and they last very well. XTR cranks having a fixed torque setting rather than "sorta tightish" possibly helps me with that...
One in the hardtail sees the worst conditions, it's probably due a replacement now but it was new when I got my 3rd Mmmbop which was about 2 years ago, I think.
Around 10'000 loaded touring miles on the Deore BB on my Long Haul Trucker. Even then it was still usable, the driveside was fine, the LH side a bit rough. I replaced it when I replaced the whole crankset.
Most of those miles, about 8000, were in the USA and only included a few days of rain on a bike with a full set of mudguards. so it seems poor fitting and water reduce the life. In UK conditions you can only do much about one of those factors.
my SLX is just on the way out (as is the bottom iS-3 headset bearing) after 13months hammering of 3-4 rides a week in woburn, bedfordshire bogfest & regular jet washing through the 'summer'.
I think I'm pretty happy with that. Do I have low expectations?
Don't know why people get so wound up about BBs not lasting - they take a lot of stick, and in fact I'm surprised they last as well as they do!
I now treat them as a consumable, and just like chains, cassettes, tyres, suspension seals - mine get changed at the annual service. Afterall, buy off one of the German online shops and they are about the cost of a chain, and we don't whinge about changing them every so often...
2,300 miles out of the XT bb that came with the crankset; replaced with an XTR bb from Rose for £16 - no grumbles with that.
My Deore has lasted about a year in Yorkshire conditions before it started sounding rough. I opened it up carefully to see if I could give it a refurb and some fresh grease, and it was very sludgey inside, so I'm not expecting much more out of it.
At £12 a pop, I'm not going to get too upset about it.
LH side not long, RH side, for ever...
Thanks for the replies. I dont really have a concern about it as i have a replacement sitting in my tool box. It was just a question on usage as i also do class the bottom bracket as a wear and tear item.
Got a few months (Winter 2010 / spring 2011) out of my first XT, have had it's replacement an XTR on since with no issues, also using a Raceface on my winter bike, and just can't seem to get it to wear out
Mine have lasted ages ... Even the one that's got FSA cranks in it is still working fine (despite having a fatter axle through it than intended).
Nothing gets pressure washed tho' ...
You can tap out the old bearings and put in some cheap new ones (6805) to save a few quid.
If I get 2 months out of one over winter I'm happy. But the bearings are only a few quid off EBay so I,m not that bothered about looking after them
Comes down to water ingress into the seals and then the balls rusting IME. One really wet ride and it's borked. Other than that they last a good while.
3-12 months depending on stuff.
Then I got a hope Stainless Steel one currently 2+ years on one and 18 months on the other one. Still perfect.
I ride mine till it's crunchy then keep riding it for another 6 months
My deore one is on it way out and isn't 3 months old yet I'm putting it down to the bog like conditions round here at the min a d having to commute on it whilst I short my single speed out
my deore BB is about 4 years old (i bought it 3rd hand with the cranks),
it's now on my commuter, where it's done at least 2000k (more than 50k per week, for more than a year).
it's fine.
7000+ on a dura ace bb and smooth as a baby's bottom.
I was going through HT2's at a fair old rate, then i found out it was partly incometence....
Then i found it it was partly buyinf the cheapo Shimano ones..
I bought the XTR's from Rose, that one is lasting MUCH better.... i'm actually not waiting for it to explode every ride.
My experience is that the Deore ones don't last that long after they get wet...the one on my hardtail has been used 10 times and is going back to CRC as its dead.
My Saint one which as been used loads more is smooth as. My XT ones have always lasted well in the past.
I'd be so happy to get a year out of XT/XTR BBs. At 10-20hrs use a week in mixed conditions, cranks lightly preloaded, 4 months on average / 3 replaced in just over a year. The sealing isn't good and the XTR are no better, from what I can see they are exactly the same inside as XT? Decent seals would help I think - they may be cheap but there's either a good reason for an open bearing or they're a poor design imo.
I think there's a reason for the design that I'm missing since shimano's stuff is otherwise excellent. But either way, when my stock of Shimano's run out I'm fitting a Hope or similar.
I had a deore one, didn't even make a year (6 months at the most), fitted an XTR one as a replacement and it's just gone past the one year mark and is as smooth as ever.
And that was roughly 50miles a week through the boggy crap and sandy granite that is Dartmoor.
Anyone know how thick the 6805 bearing needs to be? I've seen them advertised at 6 & 7mm thick
XTR are a little different internally to XT, but as far as I can tell it makes no odds.
6 months doing 4-500 miles a month riding in all conditions and hosing down between rides,
PF30 BB on my new bike 4 in 6 months,
14 months and counting on the commuter doing 125+ miles a week all weather, usually well over 12 months on the full sus, but only does a 5-600 miles a year - SLX