Bottom bracket failure - why?

dreamerb

Calling on the expertise of 410...

My bicycle had been creaking unnervingly for a couple of weeks, but for lack of time I only made it in to Commuting Solutions on Friday evening. They diagnosed it as bottom bracket needing replacing , so I've to drop it in during this week.

The bicycle (2014 Giant Dash 2) is less than a year old and can't have much more than 1200-1400 km on it. Bottom bracket is Shimano BB-ES25.

I commute to work pretty much every day: short journey, 4km each way, last 1.5km very stop-and-start due to high volume of traffic lights. I tend to coast up to reds, and try to gear up and down appropriately so I don't start off mashing. Never had BB issues with any previous bike.

That's all by way of background to my questions - is there any very obvious reason for bottom bracket failure? Have I just been unlucky? Or are there things I'm likely to be doing wrong that I should be more careful about?

lennymc

salt on the roads during winter

macnab

It might just be bad luck. It can be caused by power washing which can reduce lubrication or push dirt into the bearings which would reduce their life span.
Bearings usually have a long life unless they become contaminated with dirt, loose lubrication or are subjected to loads that they are not designed to withstand.

Outkast_IRE

There is a good bit of variation in the quality of bottom brackets. For example Shimano alone make about 5 varying quality BB for my mountain bike. With there being a generally consensus that the more expensive ones do last longer .

JBokeh

Washing with detergents can really shorten their lifespan,the detergent will make it's way in,but the water won't have the flow to wash it out,so it sits in the bearing breaking down the grease.

My MTB was a complete pig on BBs,got a new one about 700kms ago,after the old one failed spectacularly,with the bearings seizing,and then unseizing a split second later,when the bearing shell cracked. I drilled a small hole in the bottom of the BB shell in the frame. What was happening was muddy water was getting kicked up by the back wheel,onto the seat post,which was open at the top,flowing down the seat post,and actually filling up the frame with muddy water,the hole lets the frame drain,but I also stuck a handlebar plug into the bottom of the seat post

Took my "new" BB off over christmas,and popped the seals off the bearings,washed the out with alcohol,let them dry,then re-packed them with grease. Doing this will hopefully extend the lifespan of my BB,and prevent my getting stranded with an expensive scooter like the last time

dreamerb

Thanks all. Salt seems the most likely. Probably shows that I've hit the wimp list less this year than in living memory, so it's not all bad . Although OH reckons they've just put more salt on the roads...