Framebuilders - Dent on underside of chainstay

Greetings - I spend most of my time in the C&V section and posted about this issue there, but realized this forum may be my best bet. I have a mid-70s Reynolds 531 frame with a sizeable dent on the underside of the chainstay (see pic). I would appreciate your thoughts on possible method for repair and on the ability to ride as is. I am keeping the frame and would love to be able to ride it. If repair is necessary, I would appreciate your recommendations for a repair shop - I am in the Atlanta area. Best regards.

From my experience with steel bikes there would be no problem whatsoever (except aesthetics) if you ride with this.

If you were set on repairing it. I would consider drilling a 1/8" hole on the opposite side, then apply a little heat and use a pin punch to tap out the dent. Careful with the heat though. Don't exceed 400C.

Thanks for your response. I am not overly concerned about the aesthetics. It can't really be seen when the bike is upright. Someone else in another forum suggested a diamond shaped reinforcement that covers the damage in all 4 directions, extending fore and aft. Is that really necessary? Others have suggested filling it. I would appreciate your response to those suggestions.

Are you sure it's not cracked? I would probably clean up that nasty rust just to see what's going on there. Then you can paint it to keep it from rusting more

People do fill dents like this, but I wouldn't in this case. If it were cracked, I would think about putting a doubler on, if it's not cracked there is no point.

I do not believe it is cracked, but will take another look. Excuse my ignorance, but what is a doubler?


Are you sure it's not cracked? I would probably clean up that nasty rust just to see what's going on there. Then you can paint it to keep it from rusting more

People do fill dents like this, but I wouldn't in this case. If it were cracked, I would think about putting a doubler on, if it's not cracked there is no point.

Force- I also doubt that it is cracked but the first thing you should do reguardless of your solution is to get down to bare metal. Sand blasting would be the best as it won't leave a surface texture that might hinder finding a crack (if one does exist). Any filling (bondo or brass) or brazing a layer on top (the doubler I believe) or just pounding it out will still need refinishing afterwards or a clean surface to start with.

If no crack exists then my first choice would be to fill with brass, braze a layer is #2 and drilling a acess hold and pounding it out is not what i would consider at all. No sense adding three (a hole, the pounded out dent and the application of heat) additional stresses/weakenesses to the already less then structurely complete area. I will add as 009jim did that the dent is not likely to be a problem. I have seen worse go for thousands of miles without issues. Andy.

OP wants to keep and ride it, so I think he should take it to a shop where a builder can take the CS out and replace it. How valuable is the frame to you? And is it time to put your interest into a different one?

On another thread out in the Interweb there is a discussion about tube replacement. The consensous is that a complete triangle replacement is the best option when needing to replace even just one tube. This seems like a whole lot of work for a small dent on a thick walled tube. Andy.

Thanks for your response. This is the first time that replacement of the stay has been suggested to me. Yes, I want to ride the frame, but replacement of the stay seems last resort and perhaps not cost effective. What would that even cost, by the way? I am not concerned about the monetary value of the frame - I bought it cheaply, but the frame is a somewhat desirable model and I want to ride it. I have many other bikes to put my interest into, but all I can think about now is getting this one on the road.


OP wants to keep and ride it, so I think he should take it to a shop where a builder can take the CS out and replace it. How valuable is the frame to you? And is it time to put your interest into a different one?

replacing the stay will probably cost you most of $200 before paint. It doesn't look like the bike is worth it to me,but it depends on how you are going to ride it. If you were planning on riding it in such a way that it could potentially leave you stranded, replacing the stay would be a good idea. There are a select few bikes that I would put that much effort into.

As far as replacing a triangle goes, that makes a lot more sense in the front triangle than the rear triangle. In that case it was the head tube. Also, a lugged bike gets a new tube, but then again a lugged bike probably wouldn't have a cracked head tube.

Thank you for this explanation. This sounds like a reasonable approach. I believe I will attempt to ride it and determine whether I want to invest in replacing the CS, or any of the other repair methods mentioned. Thanks to all for your comments.


replacing the stay will probably cost you most of $200 before paint. It doesn't look like the bike is worth it to me,but it depends on how you are going to ride it. If you were planning on riding it in such a way that it could potentially leave you stranded, replacing the stay would be a good idea. There are a select few bikes that I would put that much effort into.

As far as replacing a triangle goes, that makes a lot more sense in the front triangle than the rear triangle. In that case it was the head tube. Also, a lugged bike gets a new tube, but then again a lugged bike probably wouldn't have a cracked head tube.