dented steel seat stay, frame still usable?

[ultrazenith]

I managed to get myself one of my unicorns a few years back, a 1994 Dynatech DIablo STX frame, but on closer inspection it had a nasty looking dent (and slight bend) in the drive side seat stay. The frame and paint job is one of my favourites of all time, much better than even the cult Kleins in my opinion, and I'm toying with the idea of just building it and riding it and seeing what happens. I know the basic cromo tubing as used on this frame would have been overbuilt and the bike, while not heavy, was not intended to be a superlight race frame, my instinct is it should hold up to normal off road use, despite the damage.

Any suggestions about how bad the integrity of the frame has been damaged, and how likely it is to fail in use? My prejudice is that if it does fail it will bend out of shape or spend a long time growing a crack, rather than suddenly snapping. What would you do in this situation?

Some photos of the damage:

 

[BlackCat]

Re:

I think it’s fine to ride - assuming we are talking typical retrobike-grade xc, not hitting 6ft drops at Innerleithen.

If it fails, it will bend - probably fairly slowly, rather than snap. Just monitor it on your snack break and post ride.

If the worst happens and it does crack, which I think unlikely, the other stay will keep the bike from collapsing under you. Just remember to listen out for the tell tale chinking and grinding of metal on metal!

 

[Captain Stupido]

I ride worse.

As long as the alignment isn't out by too much (see sheldon brown page on cold setting) it should be fine. It's pretty hard to break steel by bending it, IME.

 

[Elev12k]

how bad the integrity of the frame has been damaged

Not

 

[Frankenorange]

Re:

I would happily ride that for normal duties. Thinking back to my yoof and the trackers that we made up from dented and bent frames, cold straightened in street drains, or in vices by big brothers i think it would manage some heavy duty work, too.

 

[davez26]

Re:

I'd ride that. I like that the dent is on the side rather than totally on the 'up' side.
I am no engineer, but my understanding is that most of the load is actually at the chainstays, rather than seatstays. Some of my road bikes have pencil thin seatstays, and more often than not when the interwebs report MTB frame failure-chainstays.
Build it - Ride-On!

 

[swannymere]

I'd ride that no fear, its not really in a super critical area, i would be far more concerned if it was in the top tube or seat tube. If you're feeling brave then take a look at this Youtube video from the legend Paul Brodie about repairing dents, i'm not sure it could be applied to the seat stay as it looks like it has a taper but for the sake of an afternoon in the shed with some tools and a block off hard wood it could be worth learning.

https://youtu.be/x4D_lLqj37c

 

[ultrazenith]

Thanks for the replies and advice everyone. I'm feeling a bit more confident about using the frame now.