Bottom Bracket Drain Hole

I have seen pictures of Bicycles where someone put a small holes in the bottom of the bottom bracket tube (of course I can not find one now).

The chain stays, seat tube and down tube are all open to the bottom bracket tube. If any condensate, moisture or water accumulates in these tubes then it would drain into the the bottom bracket tube. Assuming one has a sealed cartridge bottom bracket or a sleeved cage bearing bottom bracket, does it make sense to put a small hole (maybe 1/8 inch diameter) to allow it to drain?

Yes, a drain hole makes sense. It needs to be big enough that water can drain out instead of being captured by capillary action, even when it's caked with filth. 1/4" is probably better than 1/8". And of course it should be at the low point of the BB.

Not all bikes have main tubes that open into the bottom bracket. If they don't, then there is no purpose for a drain hole

Chalo said:

...It needs to be big enough that water can drain out instead of being captured by capillary action, even when it's caked with filth. 1/4" is probably better than 1/8"....

Click to expand...

Excellent point. Thank you.

Many of teh bike frames I have had already have such a hole, at the lowest point of the frame. A few have two--one threaded for the screw that holds the plastic (sometimes metal) cable guide for derailers on the downtube, and one that's just open. A couple of those had the open hole blocked by the plastic piece. :/ (though water could still get out of there because the plastic never perfectly fits, it'd be a lot slower)

On the cheapo bikes, I've thought about drilling a hole for a grease nipple. Assuming the grease won't go fill the frame of course. Shove the sand and any water out with new grease from time to time. The extra weight no bother for an ebike.