My son has an old chrome paramount with a dented top tube. The dent isnt any real problem but I do have an aluminum block set that would fit it. I know frame blocks will remove paint but does anyone know how chrome fares under these circumstances?

In my experience, chrome plating is prone to brittleness and cracking, depending on the plating thickness. I don't think the plating would emerge unscathed, but I can imagine that a top-of-the-line frame like the paramount likely received a decent thickness to the chrome in those days.

I've used home made maple blocks to roll out dents, and managed to keep the paint damages minimal. The blocks were quick an dirty with a rough surface in the bore. I used lots of grease and stopped when the clear coat showed damage but not the paint underneath. You can buy maple frame blocks that have a much better fit and finish. Thats what I would try.

Never done any of this, but when I watch the paintless dent removal videos they use a heatgun/blowdryer to get the paint warm before trying to move metal around to minimize chipping and cracking. might help here too.

I’ve never done any of that. The chrome could crack which could cause peeling to occur, but the surface is much harder than paint.

52t,
Unless the dent is really large, personally I would deal with it by putting a decal over it. Regardless of the how well the dent is "rolled" out it will still leave a slight impression in the tube and a decal will still be necessary to "hide" it.
Using blocks, even if soft runs the risk of marring the finish.
JMO, Ben

Well I think we will leave it be! Thankyou for all the input.

Is the dent where the bars could have come around and smacked the top tube? BITD, many riders would hide (or prevent) such a dent by wrapping some bar tape in the strategic spot. I'm guessing your son's chrome Paramount has red decals, so some red bar tape (cloth, please) would look spiffy and period-correct. For a more low-key approach, Newbaums makes a gray bar tape that should be more subtle without being too matchy-matchy.

Or just leave it alone. That is absolutely a valid option.

It's actually farther back on the top tube. Kind of hard to understand how it happened but the bike is 50 years old,

Automatic garage door.

Well, since there are questions about the location of the dent...why not post a picture?
Best, Ben

The bike is at my son's house. While recovering from the flu I was wondering about some issues. I'll see if I can find a pic.

The day I picked it up in August I think. The dent actually is way less noticable in person.

That would be a tricky one to roll out...but if the chrome didn't crack will being dented, the chrome is probably NOT going to crack when rolled.

Thanks for the picture.....If this was a frame that I owned and it bothered me, I would fill it with body filler (to reduce the depression) no sanding to level and cover it with colored opaque vinyl tape. I would "consider" placing another strip equidistance from the head tube.....making it appear as if it was a clear design decision.
JM2C's, Ben

Yeah, if a handlebar did that, it would have to have been a reeeaaaalllly long stem.

Personally, I wouldn’t mess with it. If you decide to roll it, the maple blocks are probably a better option. Less chance of marking the chrome.
Cheers,
Van

Is there any way to pop out the dent from inside the tube? It almost looks like you could slide something into the top tube from the seat post opening.

I've never heard of anyone trying this, but if you got a longer aluminum tube with an inner diameter that matches the bikes top tube and an outer diameter that matches a larger aluminum frame block, you could cut the aluminum tube in half, put it over the top tube, secure it with pipe clamps so it wont rotate, and then roll the assembly with the block, there would not be any rubbing on the top tube.

Trouble would be getting the stock inside the tube......125 to 200 and maybe "paint-less" dent remover would do it, but tube stock may be too thick for it to work.
Tape and Go would be my Motto...it will never be perfect!

I have wrapped a single layer of painters tape over a painted tube, then used frame blocks lubed with marine grease to roll out a dent, with out marring the paint. I have significantly improved dents, but never completely removed one.

I also removed a dent in a chainstay near the bottom bracket. I inserted a socket close to the diameter of the tube into the stay, then used an allen wrench to load the end of the socket against the dent and pushed it out.

I worked at an aviation plant at one time, we had this tool which had hydraulic lines with different size balls on the end to feed into a tube and hydraulically expand to the dent from the inside.It worked, but we never implemented it due to quality concerns with cold working a tube. I tried to find details on it unsuccessfully.

I would think something like this could work, if the tube openings at the seat tube, steerer tube are same size as the tube - install a ball or bullet and pull it thru with a cable.

https://www.flight-mechanic.com/rigi...nd-inspection/

These guys roll out a dent on the chain stay of a Team Mongoose bmx which seems to be chrome. Not a proof that the same happens to your TT but in theory it might work.

Hey Lattz,
Great video.....but, the dent is still there and most likely all dents that are rolled out will still have a small dimple left. In order to get the dent completely out, force must also be applied to the other side of the dent......the "bump" in the bumping dolly.
Dent less paint uses a similar type of pressure behind the dent. Cups can work if there are no creases in the metal AND if it is thin enough etc.
Depending on the type of dent, sometimes heat can also be used but chrome and paint are damaged in the process.
Best, Ben

Agree with you Ben its not a perfect solution, my intension with the video was rather '"just for the record, its possible with chrome" than "watch and follow." I personally would not touch that dent with or without wooden blocks but it's me. However good to know there are people out there who do such.

Lattz,
Understood and why I said great video......it is nice to see what one can expect when using blocks. Many folks see them as a panacea for removing a dent, when in reality they can remove a little but rarely remove the dent the completely, because of the nature of deformation of the metal. Thus the bump dolly or the addition of a small amount of filler to cover the "dimple", in my estimation in the end not worth the effort if one has to fill and repaint to get rid of the dent.
Personally, if I were to go down that route (slight filler) I would skip the blocks and lightly tap down the high spots and then fill.
Best, Ben