Drilling a BB drain hole

[bikeyoulongtime]

I've come to realise that the BB shell was originally 2 pieces and it seems to have been welded down the middle so I wouldn't be drilling on that,

sounds like the 301 BB - Two forgings welded together. Theres a little bit of drillium installed in each half of the BB shell to let water out. I'd be reaching for a my calipers, a centre punch and a good, sharp 3mm drill.... one each side of the weld, avoiding BB threads or press fit bearing surfaces.

actually, here's a pic:

 

[jenk0s]

sounds like the 301 BB - Two forgings welded together. Theres a little bit of drillium installed in each half of the BB shell to let water out. I'd be reaching for a my calipers, a centre punch and a good, sharp 3mm drill.... one each side of the weld, avoiding BB threads or press fit bearing surfaces.

Yeah right, sounds like a plan. Does the 301 BB have any benefits over a one piece design? Interesting because it would probably take longer to manufacture and fabricate....

 

[bikeyoulongtime]

Yeah right, sounds like a plan. Does the 301 BB have any benefits over a one piece design? Interesting because it would probably take longer to manufacture and fabricate....

...actually no idea. Materials engineers? Welders?

There's no BB tube in there - the BB threads are just cut into the sides of a forged piece, so there's a lot of clever alignment going on at welding time - so yep, not the cheapest process there...

 

[racebmx]

Drill a hole and tap it. Then install a nice bolt.

 

[dontfeelcold]

...actually no idea. Materials engineers? Welders?

There's no BB tube in there - the BB threads are just cut into the sides of a forged piece, so there's a lot of clever alignment going on at welding time - so yep, not the cheapest process there...

BB threads would be done after welding. Lots of bikes are finished machined after welding. It's much easier to add a couple of millimetres for distortion and finish machine the headtube, bottom bracket and pivot points afterwards. My Kona is done this way and a friends NS soda FR is the same.

If the liteville use a straight section for the bottom bracket it would would just be tube. In the picture its a multi shaped structure, so they can save weight by making a hollow section following the outside shape. Not hard to do and cheaper if your going to be making a lot of an item.