Downtube tumor

A few years back I bought an '82 Heritage that had been sitting in a backyard for a while, got it cleaned up and running, modified it with wheels from an XJ550 Maxim. Ran it for the summer without many issues and then traded it in the fall for a project GS1100. The fellow I traded with, a person from work, used it the following summer without any problems. Last year though,the bike developed a high idle,symptoms of an air leak of some type? Anyway, he didn't solve the problem and hadn't ridden the bike for the past two seasons. Last month I asked him if he wanted to trade for the GR650 I've been riding. He agreed and dropped the XS off at my house yesterday. I was looking it over and noticed a bulge in the left downtube, just below the front engine mount. I'm assuming it is some type of rust. Has anybody else experienced something like this?

I left some exercise equipment outside over the winter, it rained, it froze, the tubes swelled up just like that. john

That is strange. My first thought would be a weld covered with body filler painted over. You could drill a small hole in the center of it to see how much metal is in that area, then weld and fill it or piece in a piece of similar size tube. Also, that may have been the area where a crash bar or highway bar was fastened, kinking the frame and then stiffened with weld. Dang, that's a mystery.

Scott

wrenchjohns said:

I left some exercise equipment outside over the winter, it rained, it froze, the tubes swelled up just like that. john

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Wow, that's possible. Maybe drill a small hole way south of that bulge to see if there is a glob of condensation and gunk in there.

Scott

hmusket said:

A few years back I bought an '82 Heritage that had been sitting in a backyard for a while, got it cleaned up and running, modified it with wheels from an XJ550 Maxim. Ran it for the summer without many issues and then traded it in the fall for a project GS1100. The fellow I traded with, a person from work, used it the following summer without any problems. Last year though,the bike developed a high idle,symptoms of an air leak of some type? Anyway, he didn't solve the problem and hadn't ridden the bike for the past two seasons. Last month I asked him if he wanted to trade for the GR650 I've been riding. He agreed and dropped the XS off at my house yesterday. I was looking it over and noticed a bulge in the left downtube, just below the front engine mount. I'm assuming it is some type of rust. Has anybody else experienced something like this?View attachment 87689 View attachment 87690 View attachment 87691

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Hi hmusket,
I'm with wrenchjohns, my primary suspect would be that the frame got filled with rainwater which froze, expanded and created the bulge.
I'd suggest drilling a small hole in the lowest part of the frame to see how much water runs out.
To fix the bulge you'll have to pull the motor so you can torch the bulge to red heat then carefully tap it back down again.
OTOH you could ignore the thing, the bulge don't really affect the frame strength, eh?
But about your wheel & fork swap:- What's the front wheel trail reduced to with the leading axle forks? And what forks are those?
I've managed to reduce my XS11 sidecar tug's trail by mix'n'matching triple tree parts but my XS650 rig is still using it's stock solo trail because I can't find suitable parts that'll swap. Until now.

hi that is a frost burst , seen and repaired lots of them over the years, roast it red hot knock it back into shape and weld it shut, job done

Don't waste your time drilling where the bulge is. Persuade it back and weld it to seal it up, then use that drill to give yourself a small weep hole at the bottom of the tube on each side just beyond the bend and a small vent at the top of the tube near the neck if you live in a climate where rain is common/freezing winters occur and you don't have somewhere indoors to store it in the winter time.

PS: That right there is why people use water and a freezer to pop tanks back to shape sometimes.

I was thinking it looked like a burst waterpipe, just hadn't seen anything like that before on a motorcycle frame. I was planning on dropping the engine and refinishing the frame, just one more thing to work on. Thanks for the replies.

To answer Fred's question: The front forks, swing arm and both wheels are from an XJ550, given to me (had a ruined engine).The forks are 36mm, the front wheel axle 15mm. The triple tree. IIRC, is from an '82 Virago 750, a straight bolt on.

I had a late shift at work today, so I had time to measure the trail and take some pictures. I would say the trail is somewhere between 3 and 4 inches. I also took some pix of the triple trees from both the '82 Heritage and the '78-'79 650 Special I'm working on. You can see the XS trees are offset by 1/2 - 3/4" more than the Viragos. If you have more questions let me know.