Monday morning quarterback: bicycle weld

[DaveO]

Kick stand on my daughter's bike is poorly designed: it attaches with a vertical bolt through two horizontal plates, but the weight of the bike makes the kickstand pivot around the bolt, so the bike falls over. Attempted to fix it numerous times but it kept failing and I thought, enough, just weld the dang thing and get it over with.

Saturday morning and I'm moving fast with a purpose: no research, it's not a critical frame joint, just touched a magnet to the bike and it stuck so I thought ok, cheap bike, steel, and cleaned off a little paint to get a clean electrical connection. I tack welded the plates with a 7014 stick electrode in the IMIG 200.

So now I'm actually applying the brain cells, did a search and found that chromoly is magnetic too, so the bike is likely chromoly. Did I just totally FUBAR this thing? What's the prediction for this weld?

[Big Paulie]

I had the same issue, but rather than welding the aluminum kickstand to the chrome moly frame (brazing with silicon Bronze is the only method), I think a better solution is to weld a piece of square stock to the top of the kickstand, so that it acts as an anti rotation plate/ledge, against the frame tube. This way the kickstand is still removable in case of a needed repair, and you are dealing with similar metals.

[DaveO]

Hey, BP, I should have mentioned the kickstand is steel too. The mounting surface on the bike is a plate between the forks, drilled to accept the bolt; the kickstand is more likely steel than chromoly with a threaded hole.

I actually had the same thought about attaching a ledge to prevent rotation, and yet another alternative would have been to drill another hole in the upper and lower plates to insert another bolt. The tack weld was quick and much more fun, although I'm wondering about the soundness of the weld. A web search directed me to WT&T, where Jody recommends er70-s2 filler for TIG, so I may not be too far off.

[zedron]

I highly doubt the frame is chromoly if its a cheap bike like you mentioned.

[Big Paulie]

I understand the desire to have a solution that justifies owning the welder.

how about drilling another hole in the mounting plate on the frame, through to the kickstand, then welding a stud to the kicstand that will protrude up thorugh the matching hole in the frame plate. this stud (short bolt) would serve as an anti rotation pin, and the weld would just need to hold it in place, but the stresses will all be on the stud. either way, there should not be any significant stress if it is just preventing rotation.