Bottom Bracket Noise

[beancounter]

On Saturday I was 30 odd miles into my third ride on my two week old Cannondale cyclocross bike, when a very unpleasant noise started emanating from the bottom bracket area (as far as I could tell). It was a loud graunching / grinding noise occurring on each pedal stroke (i.e. not continuously) and only under load (i.e. it didn't do it when I got off to have a look). Definitely wasn't front mech.

So back to Evans with the bike yesterday, very apologetic and helpful as you would hope and expect. Left it with them and picked it up after work, all fixed and ready to go.

The problem, apparently, an "incorrectly greased bottom bracket".

Now I gave the bike a good whizz round the car park there and then, and indeed the noise was no longer there and all felt fine. But I thought that modern bb's were sealed and therefore not possible to re-grease? The bb in question is an FSA MegaExo (according to the spec sheet) - anyone else using one of these?

Any comments gratefully received.

bc

 

[Bigtallfatbloke]

I had a similar issue but unfortunatly the LBS concerned were not as helpful as Evans. My galaxy was put into Les's cycle sin canvey for a service before my tours this summer. They told me they had replaced my BB and re greased everything etc. They tried to charge me £110 for thta job. IN th eend it cost me £85 after a row as they had not agreed any costs with me up front.Anyway, clearly they hadnt actually done th ework they tried to rip me off for as the BB broke in Basel after only 1000km. I took it to another LBS who took the BB apart in front of me and showd me the state of it. There was no way it had been recently replaced. Anyway I had them replace it and since then all has been well. The noise I had in Basel was like you describe.

 

[beancounter]

Sorry to hear about your issues with your LBS btfb. My bike is only a couple of weeks old so I would have expected it to be fixed without question or charge, which indeed it was. I'm just querying what I was told, as it doesn't seem quite right to me (although I'm no expert by any means).

bc

 

[Leadlegs]

I presume that sealed BB bearings are greased as part of the assembly process. Perhaps yours was a Monday morning/Friday afternoon example that missed this vital step.

 

[Soltydog]

I'm using the same bb & had to replace mine last week, after 2 years use. There is no greasing required as it is a sealed unit, unless they meant that it had been manufactured wrong

 

[02GF74]

^^^ don't sound right to me. unless the bottom bracket fitted is 10 years old, then all modern ones are in sealed greased bearings; grease cannot be added nor taken away.

It is not just a worn BB that has the symptoms you described - I had this recently - see my post - and it turned out not to be worn BB - I reckon it was one of the crank arms (fitted by someone else) not done up tight enough or loosened; that is what I do my maintenance myself as I know it gets done properly.

 

[beancounter]

^^^ don't sound right to me. unless the bottom bracket fitted is 10 years old, then all modern ones are in sealed greased bearings; grease cannot be added nor taken away.

It is not just a worn BB that has the symptoms you described - I had this recently - see my post - and it turned out not to be worn BB - I reckon it was one of the crank arms (fitted by someone else) not done up tight enough or loosened; that is what I do my maintenance myself as I know it gets done properly.

Yes, I did wonder if the bb was loose, or (as you say) one of the cranks.

bc