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Bottom Bracket

Rob's picture

By Rob - Posted on 15 March 2007

Replacing the BB this evening, I'm not convinced all is well in the frame here, so took a pic. One of these holes at least looks like it shouldn't be there Sad

My thumb is on the bottom of the frame, the illuminated hole centre looks very wrong. There's another at 12 o'clock in this shot that seems to line up with the bottom tube.

There's another view here.

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davis_jnr's picture
Its not isolated
Submitted by davis_jnr on Fri, 16/03/2007 - 07:08.

I noticed the same thing on my Norco a few weeks ago, where each tube attaches to the frame is a small hole...so now i am not so alarmed.....i guess you shouldnt be either????

pikey's picture
Trade practice
Submitted by pikey on Sat, 17/03/2007 - 19:44.

Prior to welding pipes together you drill a pressure relief hole in the centre of the but joint as the air in the tube expands and can blow out the "still hot" weld body before it gets a chance to cool and thus retain full strength.

Thats that the photo shows.

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