Has anyone got an explanation for this ?

[woodbutchmaster]

I am starting work on this 1970's frame and it has been pointed out to me that there are two non standard holes in the dropouts.
I have no idea why that was done but l'm not keen on it. Whats the verdict, live with it or fill them somehow ?

 

[keithmac]

Possibly to mount a mudguard or rack?.

Looks to significantly reduced the strength, could you have them brazed up?.

 

[Sittingduck]

Do you know how long they holes have been there for or can you find out? If they have been there 20 years I would probably be inclined to leave it. Curious to see others’ opinion on this.

 

[MichaelW2]

Some dropouts were drilled for added lightness. Others for fixing this:

https://www.bikeforums.net/classic-vintage/662574-campagnolo-portacatena-pictures.html

 

[woodbutchmaster]

Possibly to mount a mudguard or rack?.

Looks to significantly reduced the strength, could you have them brazed up?.

I will definitely look at having them brazed. l'd rather see a spot of braze than a hole which has no right being there !

 

[MichaelW2]

Would brazing heat affect the strength yet more?

 

[woodbutchmaster]

Do you know how long they holes have been there for or can you find out? If they have been there 20 years I would probably be inclined to leave it. Curious to see others’ opinion on this.

It's hard to know how long they have been there. The frame is approximately 1975 but the holes look relatively new , still got slightly rough edges where the bit went through.

Some dropouts were drilled for added lightness. Others for fixing this:

https://www.bikeforums.net/classic-vintage/662574-campagnolo-portacatena-pictures.html

That looks a bit dodgy to me and that dropout looks like it has two holes drilled to fit the chain guide whereas there is only one hole in each dropout on mine.

 

[midlife]

Having lived through the 70's Drillium period those holes (for a mudguard) wouldn't worry me too much. Any more pics of the rest of the frame.

 

[woodbutchmaster]

Would brazing heat affect the strength yet more?

Good point , not sure about that. Maybe l will just fill them with some silver coloured fibreglass resin. If only for appearances sake.

 

[woodbutchmaster]

Do you know how long they holes have been there for or can you find out? If they have been there 20 years I would probably be inclined to leave it. Curious to see others’ opinion on this.

They don't look that old to me but its not going to be easy to find out , l will just have to deal with them the best way l can.

 

[woodbutchmaster]

Having lived through the 70's Drillium period those holes (for a mudguard) wouldn't worry me too much. Any more pics of the rest of the frame.

Here you are.

 

[Ian H]

That the fork has mudguard eyes might be a clue.

 

[woodbutchmaster]

That the fork has mudguard eyes might be a clue.

I think you have hit the proverbial on the head

 

[sasquath]

Dropouts were usually low carbon steel not cro-moly even in golden era of Reynolds 531. You can stick weld it if you like with no adverse effect on strength.

I would not be surprised if chain and seat stays were "normal" steel too.

 

[woodbutchmaster]

Dropouts were usually low carbon steel not cro-moly even in golden era of Reynolds 531. You can stick weld it if you like with no adverse effect on strength.

I would not be surprised if chain and seat stays were "normal" steel too.

As a matter of interest ,how do l tell what the steel is ? l have stripped the paint off so can post photos of bare steel if that would help.