How worried should I be about this?

[phil653]

Number 2 son crashed on my bike today, after misjudging a corner and colliding with a metal road sign. He only suffered a graze on one finger but the main casualty was the top tube on the frame. It's an old'un, a 531 Roberts light tourer from the 1970's so maybe built by Charles snr.  There's now a significant ding in the middle of the top tube, about 2cm across. See pics.  How worried should I be about this?

[LittleWheelsandBig]

It probably won't crack. A steel top tube is lightly loaded and has a forgiving failure mode.

Most of the dent can be removed by the use of 'blocks' but the paint will be toast in that region. The remaining dent can be filled with braze or filler.

[phil653]

Thanks LWAB. That's reassuring. What are these 'blocks' of which you speak?

[LittleWheelsandBig]

http://www.bicycletool.com/frameblock1.aspx

Grease the inside and gradually tighten the vise as you rotate/ oscillate the dented tube in the blocks.

https://m.youtube.com/watch?v=JTDeXG0kweA

[aidan.f]

Good advice but we use a vice in the UK!

[phil653]

Ooh, steel being malleable is wonderful, isn't it?

Sadly, this is unlikely for me. I have neither bench nor vice and my 'workshop' is an open-fronted shed. Fettling and fiddling is fine and fun, but that's about the limit.  Maybe an old-fashioned LBS that doesn't pray only to the carbon gods might do the trick.

If I do nothing, aesthetics apart, is my frame compromised?  Your first reply suggests not.

BTW I should, er, advise aidan.f: I'm not in the UK either.

[hellymedic]

Have you checked the down tube, both visually and by touch?

[LittleWheelsandBig]

You could ride it without doing anything.

If you have no LBS to do the job, blocks are cheap and you must know somebody with a vise/ vice.

Personally, I count hard liquor as one of my vices.

[phil653]

Thanks Helly. Visual and touch test reveals no other damage, I'm relieved to report.

So, next step check the external diameter and track down some blocks, a vice and a big tin of grease.

[LittleWheelsandBig]

There is another option.
http://www.sheldonbrown.com/dent-removal.html

[robgul]

There is another option.
http://www.sheldonbrown.com/dent-removal.html

Brilliant  - I met the man at Harris Cyclery in Boston, Mass. years ago - totally nuts about bikes with incredible knowledge!

Rob

[Samuel D]

I grieved for the deaths of Sheldon Brown and Jobst Brandt. My own Princess Diana moment, twice. Even now, I get nostalgic when thinking about them, and I do that often since their writing is still everywhere on the web.

I don’t suppose we’ll see their likes again.

[phil653]

There is another option.
http://www.sheldonbrown.com/dent-removal.html

At least with this you know at a glance that it's a wind up, unlike a post on another forum that proposes filling a dented frame with water, freezing it and thus using the expansion of water into ice to push out the dents. Being written from a culture not known for their use of irony I think it was meant as a serious suggestion.