Damaged Frame Downtubes

Yorkie · Dec 2, 2017

I picked up a frame recently and I have to admit I did not inspect it thoroughly during the purchase process and now I'm the proud owner of a frame with two slightly crushed front down tubes. Looks like highway pegs were mounted to the downtubes and as a result both sides are neatly crushed. Any thoughts on what can be done to repair crushed tubes?

batrider · Dec 2, 2017

Andover Norton sells all the frame parts including the front downtubes. You'd have to have them welded in by someone who knows what they are doing.

Russ

splatt · Dec 2, 2017

drill a hole from the rear of the dent apply heat and work it out with a punch, tig or mig hole back up, file up and never think about what you've done again

jimbo · Dec 3, 2017

Frames are for sale often , get another better one.

eskasteve · Dec 3, 2017

Not sure where you're located , but in the Pacific Northwest the go-to guy for frame repair is Wasco Frame Service. http://www.wascoframe.com/ I've known Dick since the seventies and there is no one better. If you're in the USA it would be worth shipping it to him.

htown16 · Dec 3, 2017

You said slightly crushed. My Bonneville has the same thing and I've been riding it like that for over 15 years, no problems. Doubt a "slight crush" affects the frame geomety or compromises strength to any significance. Put some filler in them and repaint.

1up3down · Dec 3, 2017

When the purchased my 850 24 years ago the previous owner had also crushed the downtubes with highway pegs.
I mixed up some JB Weld and filled in the indents to make it look round again, been just fine ever since.
The down tubes are fairly thin walled and light weight on purpose as they really only are there to hang the motor from and are not subject to the more extreme forces like the much thicker and stronger main top frame. The fact that they are deformed by peg crushing does not necessarily weaken their function, it depends on the severity of the crush. No doubt most everyone will disagree with me, I am just fine with how I handled mine.

Stephen Hill · Dec 3, 2017

If it "slightly crushed", it is an aesthetic issue only. Not worth replacing the frame, or the downtubes. Just fill it with bondo and don't worry about it. You will have to go with paint rather than powdercoat, but that's no big deal.

Stephen Hill

Torontonian · Dec 3, 2017

I purchased "The Jumper" from the movie types a long time back with slightly crushed downtubes from highway bars. If you guys feel good using a little bondo or filler then I will do that come restoration time. Don't have time for it yet. Life.

tyborg15 · Dec 3, 2017

There was a recent thread on the same issue. Mine also has the crushed down tubes. Under normal condition the downtubes have mostly tension forces not compression and the general thought is that the frames are still ok.

dave M · Dec 3, 2017

Regarding powdercoating something that has been filled with a non metallic filler, I recently did a repair of a primary cover with a shallow dent that I wanted powdercoated, I mixed in some aluminium filings with the JB weld and the powder coating stuck to it very nicely.

Biscuit · Dec 4, 2017

splatt said:
drill a hole from the rear of the dent apply heat and work it out with a punch, tig or mig hole back up, file up and never think about what you've done again

Yup. in my opinion the best choice. Did this exact same repair to my BSA and there wasn't even a need for heat. A 1/4" or so hole in the back side of the dented tube and a patient "tap, tap, tap" with a punch got it round again. The welder tig'd the hole shut with no need to remove engine etc. A dressing with a file and paint and be happy with a great all-metal repair.
Grind a suitable radius on the end of your punch to prevent localized stretch marks on the tube.

Damaged Frame Downtubes

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