After removing the BB and having that grotty rusty water piss out, I finally got round to drilling a drain hole.

So, tell me that;
a) I’ve weakened the frame
b) It will go rusty where I drilled
c) That’s a great idea

APF

c

you have;
a) weakened the frame
b) made a rusty hole
c) had a shit idea

😉

depends what kind of frame you have drilled? steel or alloy? and how big a hole?

drilling a small hole less than 4mm shouldn’t cause any great issues in either type of frame.

to re-protect the frame i suggest painting the hole with some metal paint, hammerite etc… this should stop moisture getting at you frame.

a small crack will start from that hole and grow and grow and grow until the whole bike cracks into pieces.

nah good idea, just measure where the lowest point really is before you flip bike upside down and drill. i have a few holes in one now..

whytf isn’t this standard?

Did it on a Heckler I had that used to ‘fill’ up with water. BB lasted far longer and no longer had the huge amounts of mud encasing the plastic BB bit that runs between the two BB shells. All good :o) – mind you make it a small hole, I think mine was 2-3 mm

Used to work in a bike shop… Holes in BB shells lead to dog poo inside the frame…

Nothing worse than servicing a bike with dog poo inside it… Seemed to be a strangely regular occurance…

Lots of frames have hole in the shell for the plastic cable guide. So dot worry about it being weaker

Seemed to be a strangely regular occurance..

that was probably just the other mechanics windign you up 😉

Now that you’ve drilled it, you need to plug it up to stop water ingress and damage to your bottom bracket. 😀

that would have to be a dog poo cruise missile to make that entry.

anyone know about preventing stress cracks from cut/drilled aluminium? you just file around the hole or what? not worth worrying about? ditto with adding bottle cage mounts.

If it was alloy you could just screw a small bolt into it to protect the ingress suely, something like a bottle cage bolt with the excess thread sawn off..
Or a small rubber gromett thingy.

can’t say I’ve ever done this and can’t ever remember any water getting into my BB’s..

Still, first time for everything I guess.

anyone know about preventing stress cracks from cut/drilled aluminium?

Stress fractures tend to propogate from sharp corners, so as long as you’ve not drilled a square hole, you’ll be fine.

ah cool round holes here 🙂

water doesn’t get into the bb much if well greased, it gets into frame anywhere else though and drains to the bb shell, and can’t escape, rusting the bb bearings. isn’t the centre tube there to prevent this though? hmm maybe it doesn’t matter too much. on a steel frame it matters.

I thought about this for my carbon frame – water gets in the slot by the seat collar when it’s really wet. Agonised over it for ages, then had a look – there’s already a hole in there that holds the cable guide in!

Plugged the slot with some soft wax in the end. Needs replacing annually ish.