drilling frame beneath bottom bracket?

oldwelshman

I have a merida carbon fram which I think has aluminim lug for bottom bracket, dont think it is carbon.
On the top side just behind dtube there is a hole for brake cable to go through and it emerges underneathm but not at the lowest point so does not allow water to run out.
I have already lost a bottom bracket which collapsed and I strongly believe it was caused by water building up inside as there was evidence of water when I fitted new one.
I have the idea of drilling a small hole in the fram just underneath bottom bracket so that any water that goes in can drain out during ride.
has anyone done this before?

Monty Dog

Apparently this is a mod the mechanics at Disco had to do with Trek OCLV frames - the hole will need to be about 5mm in diameter, otherwise surface tension won't let the water run out. Best take out the BB first and check what materials your BB is made from as well as deburring the hole on the inside, as well as outside - BB shells are typically overbuilt and therefore understressed, so don't worry about the naysayers telling you that your bike will crack and break in two because of a little old. Some old steel frames used to have massive cut-outs on the underside of the BB - both to save weight and let the water out

oldwelshman

I have recently fitted a fsa titanium BB so will remove it and drill 5mm hole.
The frame design is a bit silly having a hole for cable but no hole to let water out!!