OEM Thorn BB: shot after ... only 2000 km!

[Roberto]

The BB that came with my frameset began to make creaking noises just last week, and these got worse and worse. I replaced it yesterday with an XT and everything was sweet again today. Does it happen frequently?

[marcg]

I haven't seen any mention of this kind of thing in the forum before so I suppose that the answer is that it doesn't happen very frequently at all.  I suppose that it is always possible to have a substandard item in any large batch and yours is probably the one.
You should send it to Thorn for them to have a look at.  It wouldn't surprise me if they refunded you the cost of your replacement as I am sure that they don't want important parts of Thorn bikes failing after 2000 miles.

I have to say that the BB which supplied on my Raven was a bulk item with a metal cap at one end and some kind of composite cap at the other.  I didn't like it at all, although I have no specialist knowledge but I wasn't comfortable with the two end caps being made of different materials.  Someone offered me a cheap secondhand Royce titanium BB of the correct length so I fitted that instead.  Just a whim.
I am very pleased with my Raven and hope to be getting a Thorn tandem in the near future.

[Roberto]

I'm absolutely pleased with my Club Tour, too. The quality and workmanship of the frameset are remarkable, but I didn't expect that such a key part as the BB would fail so soon!
As you mention, I assume that the reason of the failure was that mine was the black sheep in the big batch. Fortunately, I had a handy replacement and this was solved but just wondered if this had happened before because I regard the people at SJSC as highly competent.

[tynevalleycommuter]

Are you sure it was the BB and not either the BB needing tightening in the frame or cranks needing tightening on the BB pin? Both of these can work loose in time and need periodic tightening..... and can cause creaking noises... 'Creaking' to me doesn't really sound symptomatic of a bearing failure.

[Roberto]

From the very beginning, the left crank bolt used to come loose, but I cured this with a bit of super glue, and never heard of it again. However this was my first suspect when the 'creaking' began. When I checked that the bolt was tighten, I decided to take the BB apart from the frame. I was amazed at the amount of grease coming out between the seal and the axle.

[rogerzilla]

The UN52 that came with my new Nomad *seized* after only 70 miles.  Given the hassle and cost of postage etc I just bought a UN72 locally.