Repairing a dent in a steel frame

[Daz650]

I just discovered the frame of my impulse purchase has a ding, is this frame a lost cause? Can it be fixed or will it be more hassle than it is worth?

[robracer]

HI Daz, welcome to KSRC with that dent so close to the bottom engine mount I seriously doubt the frame would be out of alignment as the back curve looks to be intact, if you are rebuilding then look for another frame, Repair would require a section to be cut out & it would be tricky to get it to match up exact... as in trying to insert a sleeve in the bend would be a hassle & lots of time on the tube bender but not impossible.

[Daz650]

Thanks for the welcome robracer. I expected it would be a possible fix and most likely not an easy/cheap fix. If frames for these bikes were easy to come by I would happily bin it. Going to take it to someone to check it out and will weigh up the options then.

[seiko1]

Just build up the ding with fill weld and gring it back nice and smooth...
Thats what I would do anyway (and have)

Oh and Welcome

[Gosling1]

......I just discovered the frame of my impulse purchase has a ding, is this frame a lost cause? Can it be fixed or will it be more hassle than it is worth?......

No, not a lost cause at all. It can be fixed, with either Robs method of cut'n'shut, or fill'n'grind as per Psychos post.

Either way, the dent is actually pretty small, and is not going to make any difference whatsoever to frame integrity or handling or anything like that.

Keep the photos coming of the rebuild eh ? It's always good to see these old dungers getting fixed....

[oldman]

I would agree that it does not appear to be bad enough to cause structural weakness. I would, however not fill it with welding rod as this will heat the frame and take whatever temper out of the existing steel. Buff it down to the metal and fill it with a good body filler then sand it off and paint it. It will look like gnu. If you are concerned about it being out of alignment take some measurements from front to back on the wheels. Have a large shot of Jim Beam and your favorite brew and God will guide you through the process.

[timmyrocks]

if you dont want to fill it with filler,
id make a little slide hammer, weld one end of it to the frame to be fixed, heat the surrounding area and knock the dent out

then buff it smooth and use little bits of filler

works on cars lol

[Gosling1]

if you dont want to fill it with filler,
id make a little slide hammer, weld one end of it to the frame to be fixed, heat the surrounding area and knock the dent out

then buff it smooth and use little bits of filler

works on cars lol

- well, it works on thin sheet metal - but that frame is way thicker, you would need one hell of a slide hammer to pull a dent out of a frame !

[Daz650]

My first thought was to crack out my sculptural skillz and try and make it nice and round looking with some kind of bog, but the tube has been flattened so it bulges out toward the left side. If I knew it would pass rego as is I wouldn't bother doing anything to it. I don't want to spend time/money on it as it is, then get knocked back when it is all together and have to pull it all apart again to fix it.

Thanks for the input guys, much appreciated. I might start up a build thred once I get some momentum on it.

[oldman]

I could not see from the picture that it was buldging from the left side. That creates a definite structural issue. I would not trust it. take it to your trusted dealer and have them evaluate it. Better safe than having it give out on you at speed. A tubular frame gets it's strength from the tubes being round, if it's buldging your farked and I would hate to see you crash due to frame failure. Drown your sorrows in a fine shot of Jim and get it fixed properly. Good luck

[Daz650]

My bike is a '82 z650 F3. What other frames match mine so I can keep an eye out if one pops up. Does the early '80s KZ750 have the same frame?

[SLAC]

Give it to the pro to fix --- Laurie Alderton, prob cost under 100 bucks

[Sulli]

If the engine is coming out precisely where the frame is bent on the inside drill a hole the size to accomadate a pin punch proceed to carefully punch the dent out from the inside till it resembles the original shape then grind and fill the original dent and weld the hole

[Gosling1]

My bike is a '82 z650 F3. What other frames match mine so I can keep an eye out if one pops up. Does the early '80s KZ750 have the same frame?

the basic Z650 / Z750 frames are much the same - but they do have minor detail differences with small things like the position of the seat mounts and sidecover mounts. Nothing major - the engines will all bolt in and out of any of these frames, as the 650/750 bottom ends are all the same as far as the mounting positions are concerned. They all used 36mm forks as well, and the triple-clamps are pretty much interchangeable across the 650/750 range.

If you can get another z650 frame from 1979 through 1982, this would be your best bet. Just make sure you the frame is not the disc-brake model 650 - there were a couple of models made that used rear disc brakes and the frame has some mounting tabs for the rear m/c, which the drum-brake models don't have.

Personally - I would not be that concerned about that ding, unless the frame has actually developed a crack in the vicinity. If that was the case, then the frame should either be replaced or repaired by someone like Laurie Alderton. But if it is not cracked - apart from the cosmetic issues - I would just keep riding the bike with that frame, with the damaged spot tidied up as much as you can.

[the kid]

I used bronze to fill some frame issues . Not as much heat input .
Had to replace a section too . Was much easier having the original section to replace it with tho .