Anyone ever tried that? Saw a kit for cars but I'm sure it's way too big to try on a bike.
Gonna be pretty difficult on a tube but would probably work with the right rig.

The tin on a car body is thin, soft, and flexible compared to tubing on a bike. Car body not structural per se. Bike frame structural, Good luck

I returned to my car and some yahoo doubled my aluminum car hood with a piece of lumber...
might have to try.
or just pay the price.

Trouble with vac is it's limited to the pressure the atmosphere can push on the other side. If you completely evacuate the area over the dent, you'll get about 1atm of pressure. 1atm = 14.7psi. If the dent is a whole square inch (huge for a bike!), you're only going to get 14.7 pounds on it. Which probably isn't enough for a dent even a fraction of that size.

I recommend the Sheldon Brown solution...

I tried it. It sucks.

I’ll see myself out.

Unless it's a really nice vacuum, like an antique Hoover, I would just leave the dent in it.

I've done it on the thin sheetmetal of a late model car, it got "most" of the dent out. I've also removed a dent from a bicycle head tube with a steel bar a few thousands of an inch smaller than the I.D. of the head tube and I can say with total confidence that even if you COULD get it to seal on a tube there is NO way any vacuum or suction cup will pull a dent out of a bicycle frame.

Maybe a super epoxy or light cured acrylic adhesive and the vacuum dent puller combined with a slide hammer might get you somewhere, but I doubt it.
Best bet would be a tiny exhaust valve from a 4-stroke model airplane engine brazed onto the dent site, combined with a slide hammer. That might work. But then you would have to unbraze the valve from the tube when you're done.

Has anyone tried to use a stud welder/dent puller on bike tubing?


This is pretty routine in autobody work. You weld a stud to the dent, then pull on it with the puller (or better yet pull on the puller while hammering from the front). After you float the dent out you can cut the brass stud off and sand it flat.

Maybe check with a local dent wizard place.
They have a pretty wide skillset and truly unique tools.
How they'd get inside the tubing, no way of knowing.
The least they'd do is look at it and shake their head.

Braze the tube shut at both ends with a zerk fitting on one end, then pump grease in with a grease gun. Hydraulic dent removal!

Be careful of high-pressure injection injuries...

Back in my youth, I used a grease gun to push the pistons out of stuck brake calipers. Once I built up a ton of pressure and then the piston exploded out, flying across the room and embedding itself in a ceiling joist. Learned something in that moment...

Fill the dent with bondo and repaint.

A lot of metal beaters have gone studless.

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Back in the late 90's, I stacked big time in Mallorca whilst descending on hairpin bends and my (then new) road bike* flew through the trees until it hit one leaving a tidy dent in the top tube. Back home in the UK my frame-builder drilled a tiny hole in the opposite side of the top tube, pushed the dent out, filled the hole and touched up the paint.

* Columbus Max tubing, ovalized, lugged BB and fillet brazed elsewhere. Lovely.

Wow.
They sure never had that when I did my I-CAR training.
In Neenah.

I wonder what happens when you turn it up to 11?