There's a hole in my bicycle

[t47b]

There's a hole on the underside of my top tube.

Is it:

A) a drain hole
B) a hole for a braze on for attaching a racing number
C) a mistake but they didn't want to waste a bit of 531
D) none of the above

The hole...

 

[steadyrollingman]

Whatever it is, I discovered one on each of my Raleigh Record Sprint chainstays last night, so I'd be tempted to say A...

 

[t47b]

Re:

I wasn't sure about it being A) as it is the top tube you would have to be in very deep water for that to be a necessary drain point and it would probably be the least of your concerns just below drowning and sharks maybe

I can understand drain holes on chain stays/bottom brackets.

 

[FINNEY1973]

Re:

Any possibility its where a pump peg used to be brazed on? there looks to be a small indentation and bare metal suggesting its been snapped off? just a thought.

 

[Jonny69]

That hole looks like it has been drilled and it looks like it was drilled after it was painted. Also looks like it hasn't been deburred, so unlikley to have been done by a professional?

 

[half cog]

Re:

Tin worm. Needs treating or it will be all over the bike.Has it got a thread in it?Looks more the sort of hole that has been drilled to attach something to. A screw in thingamy perhaps hence my question re the thread.As I understand it the holes in chain and seat stays are more to do with allowing the hot gasses to escape during building than road water. You really would not want a joint spluttering hot flux at you. Bad for the complexion.
Regards
Peter

 

[pigman]

Re:

Yes, I'd heard the ones in stays and forks are for letting welding gases escape. I once did something similar to what the OP has, albeit on a cheap gas pipe frame. I did it to feed a dynamo wire through and thus hide the wire. Might this be similar? Possibly for a wired bike computer?

 

[oonaff]

That hole looks like it has been drilled and it looks like it was drilled after it was painted. Also looks like it hasn't been deburred, so unlikley to have been done by a professional?

elementary

 

[t47b]

Re:

It is not in the right place for a pump. There are two pump braze ons on the seat tube. It doesn't have a thread. There is no other exit/entrance point.

Good point about being drilled after painting. Or the piece that was there was removed at some point after painting.

 

[PANZR]

Drilled to allow for dent repair on the top of the TT?
Maybe there was a tiny dent that has been lightly tapped out from below. Or is that just a dumb idea?