Fixing a broken frame seat post tube

[us56456712]

I have had this 30s Snyder for quite awhile. I work on it and then loose interest and then work on it again. I got it cheap because the seatpost tube was broken off from someone putting the 5/8 inch lucky 7 seatpost too high. The lucky 7 was then sloppily welded on, probably years ago, with a stick welder. I got a one inch steel rod and drilled a 5/8 hole in it with my drill press. I then cut off the lucky 7 seatpost. I drilled out the old seatpost. I plan to insert a 5/8 rod through the hole in the one inch rod and into the frame. I will hold it in place with magnets and tack it in place once I clean up all the cutting oil. One of my buddies is a fabricator and a riding partner and he will do the final welding. I don't know when I will get around to finishing it. I have everything, I just need motivation.
Here it is with no seat post clamp with the lucky 7 welded onto the frame.

It's cold outside so I did the cutting and flat filing in my front hall.

Seatpost cutoff and ready to be flat filed.

Sometimes things work out as you hoped. The seatpost was only in the seatpost tube about 2 inches so drilling was a snap. I did bust off two smaller drills making pilot holes.

Mock up. I may cut it down shorter but I will have to consult my fabrication buddy first. I feel that a taller clamp would reduce some of the pressure around the brazing when the clamp is tightened. Any thoughts on this worry, or am I fussing about this needlessly?

 

[late for dinner]

I think that cutting the neck down a bit might be a good move.
The factory brazing should hold just as well as it has 'til now and a taller neck could possibly put more pressure on the brazing or be weaker itself due to extra leverage of the inserted post, Esp a lucky 7 type.
Before putting the bike back in use I'd also remind you to clean out the bottom bracket and service bearings due to any metal shavings and debris from this repair.
That's just my 2 cents, but your fab guy'll have a solid solution.

 

[LukeTheJoker]

You have done some good work there! Looking forward to the finished result!

Luke.

 

[us56456712]

I think that cutting the neck down a bit might be a good move.
The factory brazing should hold just as well as it has 'til now and a taller neck could possibly put more pressure on the brazing or be weaker itself due to extra leverage of the inserted post, Esp a lucky 7 type.
Before putting the bike back in use I'd also remind you to clean out the bottom bracket and service bearings due to any metal shavings and debris from this repair.
That's just my 2 cents, but your fab guy'll have a solid solution.

Thanks for the reminder, I was planning on rebuilding the crank but I have a tendency to forget stuff. It is really full of rough shavings and there was quite a bit of rust once I broke thru. I want to finish assembling it and then take it apart and rebuild everything. My buddy Ed the fabricator told me I should cut it down to. It does look a little silly sitting so high. Thanks for the input.

 

[Bicycle808]

That's awesome that you're gonna save that frame. I've always liked those "rainbow" frames; is yours a 20" or an 18"? In either case, Late for Dinner makes a good point about the leverage that may be created by putting the "collar" up too high....

 

[us56456712]

That's awesome that you're gonna save that frame. I've always liked those "rainbow" frames; is yours a 20" or an 18"? In either case, Late for Dinner makes a good point about the leverage that may be created by putting the "collar" up too high....

Sounds like I have to cut it pretty much flush with the pinch collar. Thanks for the advice. I would have left it without advice. Im glad I got lazy and didn't clean it up and tack it. I would have to cut it again. It's an 18 inch.