How long should a bottom bracket last?

[Deleted member 35268]

Do you guys use the covers (like rather big washers) that cover the BB or do you go commando. I'm sure i'm getting less life as more water is getting in in the winter.

 

[Spinney]

Covers?
My problems could be due to stuff getting in. Not that I commute or ride much in horrid conditions, but the bike does get taken 200 miles up the motorway and 200 back on the back of the car several times a year.

 

[I like Skol]

A few things that can kill the Hollowtech Bottom brackets prematurely;

• over/under pre-loaded bearings
• badly faced BB shell
• water ingress

I found the BB in my hybrid was actually badly fitted in the factory and didn't have enough spacers installed (was probably only around 1mm short) but this meant the bearings were not held correctly and maybe also allowed more of the weather into the set-up than would otherwise have got in. I only found this out when replacing for the second time after the first two failed shortly before reaching 2k. The left crank arm was bottoming on the splines before making proper contact with the bearings. I also swapped to the slightly more expensive BB70 (£10 v £15) at the same time and then got around 6k out of that set before it got a bit rumbly again.

IMO it is a poor design that can be badly affected by too many outside factors when compared to the good old fashioned UN55 square taper BB which is a true cartridge BB that is fit and forget.

 

[Racing roadkill]

I've found BB's to be quite variable in their life spans. I've had Pressfit BB30's, ridden in good conditions, give up in less than 2000 miles, screw cup (external cup ) BB's ridden in poor conditions, last for 10000 miles plus. I've had Shimano Cartridge type square taper BB's last for over 15000 miles, in all sorts of conditions, and Truvativ BB's fail much sooner. They really do seem to fail randomly. I've also found a creak, which I thought was the 'death creak' wasn't coming from the BB at all, or that it was just the fact that the cups weren't seated properly, or the circlips behind the cups were broken, or the wave washer was broken.

 

[Drago]

A few things that can kill the Hollowtech Bottom brackets prematurely;

• over/under pre-loaded bearings
• badly faced BB shell
• water ingress

And simply using them.

 

[jefmcg]

BTW, I can't really believe that a Shimano BB would usually only last 2000 miles. Things do fail early, so I wouldn't be too suspicious of this failure. But if it only lasted 2000 miles on average, then you'd have to replace it before doing a long audax.

 

[Hacienda71]

Just to balance all the big figures I had a SRAM GXP (I think) BB seize solid after ~2k miles

To balance that my last to GXP BB's have both lasted for 10,000 miles plus.

 

[glenn forger]

3000 miles, anyone who says different is a wrong 'un.

 

[cyberknight]

Square tape, which yours is, 2500-10,000 miles depending upon use

Hollowtech II I get 6000-10000 miles.

I got about 6000 miles out of my truative powerspline BB on the commuter, about to replace it as its getting rough and a bit wobbly.

 

[Soltydog]

I don't keep exact records, but my FSA BB went after about 6 months of getting a bike, probably no more than 1500 miles & the second one did something similar I switched to Shimano & they lasted years rather than months. LBS said big/powerful riders are more likely to wear them out quicker

 

[I like Skol]

LBS said big/powerful riders are more likely to wear them out quicker

So was yours faulty then?

 

[ayceejay]

I don't know how the water gets in but it does and it is rare for a frame to have a drainage hole so make sure you or the LBS use a proper grease on the cup thread or whatever is equivalent for a press fit. Alternatively remove for drainage periodically.

 

[Soltydog]

So was yours faulty then?

he said big first, then maybe was worried I'd take offence so added powerful lol. but since them days I'm not as big & probably more powerful

 

[Deleted member 1258]

You're right - my error.

So 2,000 miles is too little imo.

The bottom bracket on my Tiagra equipped Eastway has started creaking after just over 12 months and 2500 miles, theres no play in it and it doesn't feel rough, it just creaks.

 

[Milkfloat]

You are lucky, my BB30 creaked after 200 miles. Grease stopped that for another 1000. Then it creaked again which grease did not fix, so I installed new bearings. It still creaked, so I have gone the loctite route - no more creaks now.